Horticulture

The mean DLI in the greenhouse was significantly lower than GREENBOX, with average values of 14.52 and 10.44 mol/m2·d over summer and winter, respectively. Thus, the light conditions in the GREENBOX could be consistently regulated at the grower’s discretion for optimal growth. Although the DLI in the GREENBOX showed a slight decline over each growing cycle due to the depreciation of light bulbs , the variations were so small that open field or greenhouse structures could not replicate due to changes in weather conditions and length of daytime over the year. The temperature regimes inside GREENBOXES were in the optimal range  to sustain lettuce growth over summer and winter without significant variation over the day . However, the greenhouse temperatures exceeded the optimal temperatures with a significantly higher variation, especially during summer . The main heating source in the GREENBOX is the lighting element. Due to the insulation from external weather fluctuations provided by the warehouse and the thermally insulated walls of GREENBOX structure, the seasonal and diurnal temperature variations were minimal over the year compared to the greenhouse . The GREENBOX structures also sustained ambient humidity conditions between 40% – 60%  for most of the time, higher in summer and lower in winter. In any case, the relative humidity was below 70% and thus did not affect crop growth. The average relative humidity was lower over summer  and winter  in GREENBOX, and higher in greenhouse in the summer  and winter,with a much higher variation over the day in the greenhouse .

The fluctuations are significantly higher and immediate to weather events such as cloud cover and precipitation as the greenhouse is directly exposed to external elements. Overall, the lettuce crops’ environmental conditions over the summer and winter indicated that GREENBOX technology could provide the desired environment to sustain growth year-round, with lower fluctuations and higher consistency . The biomass and productivity data collected at harvest found that measured variables were similar across growing locations,mobile grow rack with slightly higher values over summer than winter, as presented in Table 2. The dry weight at harvest was higher in the greenhouse  than GREENBOX .We found the wet weight is consistently higher in summer  than in winter.Wet weight and dry weight represent the cumulative amount of gas exchange in photosynthesis and evapotranspiration over the growing cycle. The productivity across growing locations was not significantly different in the same season but was higher over the summer than in winter . There were subtle differences among seasons, but such differences did not cause a significant difference in crop growth and productivity over growing locations. The results indicate that the GREENBOX provided the required environmental conditions to sustain lettuce crop growth from seedling to full bloom and ready for consumption. The growth in the GREENBOX followed similar patterns to greenhouse crop production . Furthermore, the environmental conditions provided in both growing locations were within the optimal range for crop sustenance. Environmental parameters were more consistent and controllable in the GREENBOX. The temperature variations over summer were almost five times higher in the greenhouse  than GREENBOX . However, the variations over winter were not that drastically variable over both growing locations. We attribute the higher variability in the greenhouse over summer due to the lower capability of the greenhouse climate control in response to the high variation in solar energy.

Summer has the longest duration of light over the year, and despite using shade curtains to control the intensity of sun rays hitting the crops, the trapped infrared rays led to higher temperatures in the greenhouse . Care must be taken to maintain relative humidity at an optimum level, as high relative humidity can lead to fungal disease, and if relative humidity is too low it can cause stunted growth. The GREENBOX and greenhouse provided these conditions comfortably during growth over the summer and winter. As expected, the humidity over winter in both growing locations was lower than in summer. Variations in relative humidity over winter were significantly higher in the greenhouse  than GREENBOX . The variation over winter was higher in the greenhouse  than GREENBOX . The relative humidity trends in the greenhouse were directly affected by external weather, sometimes rising to almost 96% during a rainstorm and decreasing to lower values when there is no rain for an extended time. By virtue of the GREENBOX having an independent lighting source, crop production is not dependent on sunlight and variation on cloud covers and weather events. There are advantages to growing crops in a controlled environment. The GREENBOX is not as drastically affected by the external weather due to the sole reliance on an artificial lighting source for its photosynthetic needs. Lettuce crop production times vary year-round due to differences in daylight  length over the year. However, year-round lettuce production is possible by maintaining a consistent DLI, lighting intensity, and time length. Controlled environment agriculture can achieve uniform crop and extension ofgrowing seasons by controlling environmental and cultural factors. Future GREENBOX trials include a heater/air conditioners combination to precisely modulate temperature levels and a combination of humidifier/dehumidifier to control moisture levels at optimal levels. While the productivity was similar in the GREENBOX and greenhouse, there was a noticeable difference in productivity  and wet weight  at harvest between the summer and winter. We attribute this phenomenon to a higher evapotranspiration rate and subsequent growth due to higher temperatures.

The GREENBOX primary heating source was the lighting element; future iterations may include a heat pump to supplement heat sources to combat colder conditions. In response to the growing awareness of the carbon footprint associated with increased food miles, a growing social movement has been to eat locally sourced food . As a result, there is a growing consumer base of locavores willing to pay a premium for locally grown produce that is hyper-fresh. The total supply chain of food needs 4200 miles  of movement, and 1020 miles  is the final average food miles traveled in the United States. Therefore, ebb and flow table a decrease in food miles traveled can be linked to a lower carbon footprint and alleviate the effects of climate change. When placed in strategic areas, GREENBOX can potentially reduce the food miles problem by making fresh produce more accessible. Scaling up localized high yield controlled environment agricultural setups  can help increase the resilience of the food supply systems. With GREENBOX technology, one can design plant factory setups closer to the point of consumption  such that the produce can be quickly harvested and sold, saving resources on preservation and transportation, along with space saved for inventory. There is promising potential for the GREENBOX in leafy green crop production in urban areas. Consumption growth and increasing populations will mean that global food demand will comfortably exist for forty years at a minimum. Over twenty years, a five-fold increase in sales has been noted for salad-mixes in the United States. As of 2018, worldwide controlled environment agriculture was valued at 26.8 billion USD, with a projected 9.19% growth between 2020-2025. Leafy vegetables such as lettuce are also gaining popularity as they represent practical and convenient foods with high nutritional content. Clinical investigations have demonstrated a direct inverse link between a lower incidence of chronic disease  and high consumption of green leafy vegetables, owing to it being a good source of antioxidants, phytochemicals, vitamins, and minerals. GREENBOX can potentially serve as an excellent resource for educational purposes. Students from various disciplines such as engineering, life sciences, and technology can learn of all ages. Urban areas can easily meet the resources requirements for a viable urbanagricultural setup, such as light, heat, carbon dioxide, water, space, and airflow. GREENBOX may use water from the city water supply but can use greywater or stormwater streams in cities. There are many potential avenues in urban areas that GREENBOX can be used such as underground unused tunnels and basements, flat, unused rooftops, vacant spaces in occupied buildings such as atriums, open planned spaces and corridors, and abandoned vacant spaces within buildings . There is great potential for incorporating CEA setups in urban areas as more than 60% of construction is pending to match the projected urban area to be developed by 2030. There are new commercial establishments in this field, such as Gotham Greens claims that their crop production is 30 times more compared to traditional methods with locations in New York and Chicago and are rapidly expanding across the United States. There are many goals future iterations of GREENBOX can aim for as a CEA setup. An ideal CEA setup must strive for a decrease in variation in environmental parameters. An ideal CEA setup should be designed to be upgraded with the least cost and minimum modification and maintenance. An ideal CEA setup should strive for the right balance between automation , labor-saving measures, and job security. CEA setups have the advantage of a small physical footprint. We may also include different types of crop growth such as spinach, pakchoi, kale, swiss chard, among many others. We may also use fruiting plants such as cherry tomatoes, strawberries, among many others.

Our current study used warehouse conditions for GREENBOX crop production; we can also use other areas such as abandoned mills, strip malls, or shipping containers. The current project was a pilot study as a proof of concept, and therefore we used commercially available materials to assemble the GREENBOX. Future trials may include materials that use low-cost thermally insulated prototypes and are explicitly designed for this purpose. Workers often suffer in heavy, especially those who are using. The equipment with the nature of the seismic events of significant health problems was encouraged to study and analyze and measure the vibration of workers in this area, which is one of the most interesting engineering applications. This physical factor that acts on the human body is vibration which transmits the mechanical energy from sources of oscillation. Vibration can effect in different way to the operators; machine operators are always meeting two different types of vibration: vibrations effect to the whole-body produce through seat or floor and feet, and vibration which produced by the hand-grip. Both forms of vibration can effect on the operator which reduce on his job performance and health. Farm tractors and other earth-moving equipment contribute to some of the most common, prolonged, and severe occupational exposures of vehicle vibration among equipment operators. Disturbances in finger blood flow, and in neurological and motor functions of the hand and arm can produce by excessive exposure to hand-transmitted vibration. It has been estimated that 1.7% – 3.6% of the American and European workers are exposed to potentially harmful hand transmitted vibration. The European list of recognized occupational diseases inserted these disorders. The term “handarm vibration syndrome”  is a case resulting with the exposure of machincal vibrating transmitted through hand and arm that affect in disorders vascular, neurologic, and musculoskeletal. Although that are a very important issue and serious in many nation, small concern are paid to that. Nearly any user of agricultural tools is exposed to “whole body vibration “or” hand arm vibration”. Even people on work that seems simple careers such as cutting the grass in the garden by the machine or driving the tractor in the orchards can be exposed to sudden vibration; especially vibration resulted from the handle to the driver’s hands. This vibration was known as a trouble. Vibration in tractor depends on many factors velocity of tractor, topography of field, tractor condition and design tractor and configuration which is by dynamic response. Vibration power resulting to use a lot of different types of agriculture’s tools can cause hand vibration in the tractor driver, and used density of these tools can affect the nervous system such as changes in tendons, tissue diseases, muscles, bones and the vascular injury which also results lower blood flow that is the most common complication of this type of vibration which can produce white fingers. The vibration entering to the operator hand not only causes health problems, but also lowers the driver working skills and sensation; using this type of tractors is very common in small and medium orchards and vegetable farms; these tractors considered easy to use and the cheapness, and these types known as small size tractor or single-axle tractor can be used in many agricultural operations like harvesting, plant protection, irrigation, threshing, and transportation.

Cultivars can be combined with early,mid, and late season ripening to extend the harvest season over 6 to 8 weeks.The intended method of harvest also affects cultivar selection, such as mechanical harvesting or hand harvesting . For mechanical harvesting, plants should exhibit concentrated ripening periods, moderate vigor, a moderate number of narrowly upright canes , a large number of flower buds and canes, a high resistance to wound pathogens, small to moderate fruit size, a light blue color,small scars, loose fruit clusters, moderate ease of fruit removal, crisp flesh texture,a firm berry, tough/elastic skin, and desirable sugar/acid ratio to assure extended shelf life . According to Ne Smith et al . , “Climax” is considered the standard in Georgia for mechanically harvested blueberries for the fresh market. It has an upright form, narrow crown, and a concentrated harvest . When compared to blueberry crops harvested by commercial hand-pickers,Van Dalfsen  found mechanical harvesters had a reduction in yield of 14 to16%, and roughly ten times as many immature berries.Historically, high yield and firmness to withstand shipping were the primary characteristics selected for, but over the past two decades fresh blueberry consumption has increased, leading to emphasis on other qualities such as berry size, increased shelf life, and increased berry quality .

Fresh blueberries are being shipped longer distances as blueberry gains popularity, causing an increase in demand for fruit that are of high quality, reduced softening, and increased shelf life . Marketing of rabbiteyes in the southern states ranges from 90%local sales in South Carolina to 95% shipping in Georgia . Berry size and quality are extremely important for fresh market blueberries, flower pot and firm varieties are well-suited for long-distance shipping . Crops grown for farmers’ markets need to be of very high quality, but firmness for shipping is not as much of a concern .Firmness is one of the key factors analyzed for cultivar selection , and rabbiteye blueberries are more firm than those of northern high bush or the evergreen blueberry. Cultivars with softer berries will often bruise if they are harvested mechanically and do not withstand ship ping well.Machine harvested berries have been found to be softer and show a higher incidence of post harvest decay than hand harvested berries due to damage from the machine harvester . As farms and farm cooperatives continue to grow in size with large plantings and shipping distances increase, firmer rabbiteye fruits will be needed for mechanical harvesting and shipping . Marshall et al .  showed that when breeding efforts are aimed at producing firmer fruits, cultivars may be selected that are susceptible to rain induced cracking, as firmer varieties tend to have more susceptibility to cracking. Cultivars should be screened for both firmness and susceptibility to cracking .The quality of fresh fruit is usually indicated by four major aspects: visual quality ; organoleptic quality ; nutritional quality and hygienic quality.

Fruit size is among the most important traits for the fresh blueberry market, but cultivars that consistently produce large berries over multiple harvests are needed . In a study comparing sensory and instrumental qualities of blueberries, Saftner et al .  found that sensory scores for appearance were best correlated with berry size. In other words, consumers prefer larger berries. The sensory qualities, such as berry size, color, size, and taste are likely the most influential factor on blueberry preference in farmers’ markets .Customers of farmers’ markets expect higher quality produce, but are also willing to pay premium prices .Berry color is an important factor of fruit quality, and deep-blue berries with a waxy coat, producing a light-blue berry tend to be the most desirable.Blueberries are deep purple to black, but the berries are covered by a glaucous covering, giving blueberries their bluish color . Berry color is affected by both the total anthocyanin content coupled with the quantity and structure of the waxy coating and is a highly complicated attribute . The color is highly influenced by the state of the epicuticular wax found on the berries and the presence of rodlet wax structures, which are responsible for the light blue color found on some blueberries . Generally, the lack of a waxy bloom is an indicator of post-harvest mishandling or overripe berries .A blueberry’s taste is a component of several factors, particularly the aromaticvolatiles, SSC, TA, and the SSC/TA ratio . It is difficult to accurately rate flavor, but blueberries should have a good balance of sugar to acid with a good aftertaste.

The tangy taste in blueberry is due partially to the tartness whichcounter balances the sweetness . Austin and Bondari  determined that high soluble solids content with low acid tended to be a pleasant tasting berry, but that low total acid negatively affects storage capacity. Soluble solids, pH, and SSC/TA ratio have been shown to be correlated with berry deterioration, but the SSC/TA ratio is the best indicator . Rabbiteye blueberries are tart when they first turn blue, and often get a negative image in the marketplace because fruit are often picked at this stage . Berry maturity at harvest is one of the main factors affecting storage life and berry quality, as berries do not continue to ripen after harvest. Ultimately there must be a compromise between ensuring the optimum eating quality and providing the flexibility needed for marketing as well as transportation .Rabbiteye blueberries tend to be more resistant than high bush to post harvest decay, and they also typically have a smaller, dry picking scar . This scar is considered to be the primary path of entry for post harvest decay organisms, thus a small, hydroponic grow system dry picking scar is a desirable fruit characteristic. Large berries with small, dry picking scars are the most desirable, but cultivars that produce larger berries often produce larger picking scars .This study is aimed to evaluate the performance of 11 new releases and well-established rabbiteye blueberry cultivars in North Alabama. Science-based cultivar evaluation will help growers select the best suited blueberry cultivars for their growing location and targeted market, to sustain blueberry production, and can lead to increased profits. There is limited information available on blueberry cultivar performance in Alabama and particularly in North Alabama. A study by Dozier et al .  conducted nearly two decades ago in southern Alabama evaluated several rabbiteye cultivars, but information is lacking on the performanceof newly released rabbiteye cultivars in various locations throughout the state.Our objective in this study is to evaluate the vegetative growth and development,yield potential, and fruit quality of newly released and well-established rabbiteye blueberry cultivars for their performance in Alabama. Flower bud density was determined as a number of flower buds per cane cross sectional area  in 2009. The diameters of 2 canes per bush, with a diameter between 1.0 and 3.0 cm, were measured and flagged, and the number of flowers was counted on each cane.

Flower bud density was expressed by the number of flower buds per unit cross sectional area. Due to an increase in plant size and crop load, this method was not feasible in the 2010 season, when fruit set was determined by flagging 2 fruiting shoots of a similar size  on each bush. The length of the fruiting shoot was measured and the fruit were counted. The shoot length was divided by the number of fruit set in order to determine the number of fruit per unit fruiting shoot. To obtain the initial fruit set, data was collected in May, and then the same shoots were counted again just before harvest in late June to determine the final fruit set.Experimental bushes were hand-harvested on a weekly basis, starting when approximately 50% of the berries on the bush were fully colored, and bushes without a significant number of ripe berries were not harvested. Yield data were recorded on each harvest date for each experimental plant. In addition to determining the average yield per bush per harvest, the average total yields per bush were determined across both seasons.Berry sub samples were collected from each harvested bush to determine cultivar fruit qualities characteristics. Berries were placed in a cooler and kept at4˚C before analysis. A 20 g sub sample from each plant harvested was stored at−80˚C for later determination of soluble solids content , titratable acidity, and pH.The fruit quality analysis was performed by measuring berry surface color,average fruit weight, firmness, number of berries with wet scar, berry dry weight,soluble solids content , titratable acidity , the SSC/TA ratio, and pH.The average berry weight was determined on a 50 berry sub-sample/bush. Fruit firmness was determined on a 10 berry sub-sample/bush using a handheld FT 02penetrometer  using a 1.5 mm probe. Accordingto NeSmith  berries that have firmness exceeding 175 g/mm are likely a good threshold for berries that are suitable for mechanical harvesting.Fruit were held stationary between the thumb and index finger on a flat surface,and the probe was pressed against the fruit in a slow and steady motion until the erry was pierced. The percentage of berries with wet picking scar was determined by examining a 50 berry sub-sample per bush. Berry dry weight  was determined by drying 10 berry sub-sample/bush at 77˚C in a Grieve model sc-350oven  for 36 hours, and then the berry weight was recorded.SSC, TA, and pH were determined using a method described by Vinson et al .. SSC was determined by first pureeing approximately 20 g of frozen fruit and20 ml of HPLC water, obtained from a Millipore Direct-Q 5 filter system , using a ceramic mortar and pestle into a homogeneous liquid . The resulting liquid was analyzed using a digital refractometer  to determine the % SSC at room temperature. To determine TA, the homogeneous liquid was clarified with a centrifuge at 15,000 gn at4◦C for 20 minutes , and the supernatant was filtered with double-layered cheese cloth. The resulting supernatant was brought to a final volume of 40 mL with HPLC water and thoroughly mixed. Five mL of supernatant were diluted to a final volume of 30 mL with HPLC water, which was used to determine TA with an automated titrimeter . The titrimeter was maintained at 10◦C in a Fisher Scientific refrigerated chromatography chamber . A 0.1 M solution of NaOH was titrated to an end point ofpH 8.1. The results were expressed as citric acid equivalent through the following formula: . SSC: TA ratio was determined by dividing SSC by TA. The titrimeter also determines the pH of the sample used to determine the TA . Cultivar vegetative characteristics were evaluated by determining leaf area,chlorophyll readings, and plant growth index.

Average leaf area was based on a30 leaf sample per bush collected late summer and measured with a LicorLI-3100 area meter . Mature leaves located at least 5 nodes away from the terminal bud were used. Chlorophyll readings were taken on 10leaves per experimental bush. Mature leaves located at least 5 nodes back from the terminal bud were used. Bush heights, as well as the plant width measured perpendicularly and diagonally to the planting row were measured to determine plant growth index of each experimental plant. Phosphorus  deficiency contributes to reduced yield potential of dry bean. The most pronounced effect of P deficiency on plant growth is reduced leaf size, and increased root growth . Accordingly, phosphorus deficiency in dry bean decreases shoot to root biomass ratio but has no effect on the rate of photosynthesis per unit leaf area .Often P is limiting in tropical soils due to low pH of the soils and high P fixation capacity. Correcting P deficiency is possible through organic or inorganic fertilizer inputs . While applying inorganic fertilizers at low rates can be cost-effective, crop response is often hampered by high P fixation in the soil.

Plant breeders have been successful in selecting carrot, sweet potato, and tomato cultivars with comparably high carotenoid levels and vitamin A content; onion and tomato cultivars with longer shelf-lives, sweet corn cultivars that maintain their sweetness longer after harvest; cantaloupe and watermelon cultivars with higher sugar content and firmer flesh, etc.. These are just a few examples of how genetic manipulation has contributed to improving the quality of vegetables and post-harvest po- tential. Breeders have also developed vegetable cultivars with improved storage characteristics, including resistance to storage fungi and pests, as well as physiological disorders. More adequate and sustained funding for this work is required, as well as improved linkages among breeders, nutritionists, health sector experts, and policymakers.Many opportunities exist for applying biotechnology to improve the post-harvest quality and safety of fresh vegetables. The year-round provision of safe, nutritious vegetable crops to consumers has, over the past 50 years, primarily been through a combination of locally-produced and imported vegetable crops that have been handled through various transport and storage regimes, and shipped to both local consumers and to opposite hemispheres using such methods.

The high costs of energy for transport and for storage, changes in consumer consumption preferences, grow lights and changes in consumer concerns , increasingly mean that these options may no longer be viable for some markets that want vegetables produced under a reduced carbon footprints. Many vegetables particularly in tropical and sub- tropical countries have now a gross over-supply during a very concentrated production season. The aim is to ex-tend the production season, and consequently the period available for marketing. The use of different vegetable cultivars in different seasons, and photoperiodic and vernalization sensitive cultivars for changing the flowering and therefore the production season, together with the use of special fertiliser and water regimes for shifting the flowering and vernalization time are effective and proven approaches that can be used for year-round sup- ply of vegetable markets. Temperate vegetable crops can also be developed for extended production seasons as evidenced by the change in day length dependency in strawberry. Improved production using improved landrace vegetables and production under greenhouses should be also considered. The production and marketing of vegetables crops is undergoing continuous change globally. This is mainly due to the growing demands of consumers for safe and healthy vegetables, increased urbanisation of societies, and the growth in scale and influence of supermarkets chains. The changes outlined above are merely some of the factors that are impacting on current production practices for vegetable crops. They also provide a plethora of opportunities for vegetable breeding and horticultural science to solve many of the current problems facing producers and to offer solutions to those issues that are concerning consumers.

Horticultural science can respond to many of these challenges through research, breeding and innovation that can seek to gain more efficient methods of crop production, refined post-harvest storage and handling methods, newer and higher value vegetable cultivars and demonstration of their health benefits. Horticulturists will need to develop cultural practices and vegetable breeders to breed vegetables for a multi-functional horticulture  and to cope with harsher climate conditions and lower inputs than they have come to expect. Improved production systems that can cope with climate extremes must allow vegetables to produce under high temperatures, greater drought stress, increased soil salinity, and periodic flooding. This will involve a combination of improved vegetable cultivars and modified production systems. The continued globalisation of the vegetable industry will see a rapid transfer and adoption of knowledge. This will include the transfer from developed to developing countries as major enterprises move to year-round production and in response to securing lower-cost land and labour. Many of these activities will, however, be carried out by the private sector where the protection of intellectual property, the development of unique and proprietary vegetable cultivars and the advocacy of brands will, undoubtedly, see a markedly diminished involvement of the public sector. Modern trends indicate that consumers are seeking increased variety, novelty, and healthy options in their eating choices. Creation of vegetable hybrids is a key means towards the development of cultivars for modern vegetable production. Hybrid seed production is high technology and a cost intensive venture.

Only well organized seed companies with good scientific manpower and well equipped research facilities can afford seed production. Due to globalization most vegetable breeding research and cultivar development in the world are presently conducted and funded in the private sector, mainly by huge multinational seed companies. Public vegetable breeders and cultivar development activities and research are disappearing worldwide. This means in general that there are fewer decision-making centers for vegetable breeding and cultivar development. This has also resulted in the focus on relatively few major vegetables produced world-wide, to the detriment of all the other cultivated vegetables. It is imperative that national governments and policymakers, led grow lights as part of a social duty, invest in breeding re-search and cultivar development of traditional open-pollinated cultivars and in the minor and so-called ‘‘forgot-ten’’ vegetables. Developing vegetable cultivars that are more tolerant of environmental extremes should not be limited to only those of global importance. Many landrace vegetables from the tropics already are well adapted to the climatic conditions likely to be more wide-spread in the future. Many are highly nutritious and familiar to smallholder farmers, and can provide excel-lent opportunities to help farmers cope with climate change. Smaller seed companies, which are usually specialize in few vegetable crops, must be supported, possibly through autonomous affiliation with the larger companies. More investments in this area will mean less expensive seed for growers to choose from, and an increased preservation of vegetable biodiversity. The accomplishment of this goal may require new approaches to vegetable breeding research and development by both the public and private sector. Public plant breeding remains a key component of vegetable research systems worldwide, especially in developing countries. However, the increasing presence of private sector breeding and a decrease in national and international support make it difficult for the public sec-tor to continue operating in the traditional manner. Declining funding for public vegetable breeding coupled with the rapid increase of vegetable production and consumption and an urbanizing population, has created a difficult situation. Public sector breeding must be strenghened. More public sector vegetable breeders are needed worldwide to select and to produce non-hybrid cultivars of the minor and ‘‘forgotten’’ vegetables. Breeding of vegetables and other minor crops must continue as a viable endeavor. Improving landrace vegetables is particularly important for the poorest. This will benefit small farmers, and will safeguard biodiversity and food security in developing countries. Currently there are too few vegetable breeders to satisfy global demands and opportunities in the public and private sectors of developing and developed countries. In order to meet future needs, it is important that educational programs incorporate rapidly changing new technologies along with classical content and methods in order to meet professional needs for vegetable cultivar developers, researchers, teachers and support scientists. Vegetable crop improvement powered through plant breeding is critical for sustainable production of vegetable crops that contribute to healthful diets and enhance quality of life for people around the world.

Policymakers and investors have to turn their attention to enhanced funding for the vegetable and horticultural sector, allowing farmers to compete with their products on a world market increasingly determined by market quality standards and phytosanitary concerns and regulations. Many current vegetable breeding efforts remain under-funded and disorganized. There is a great need for a more focused, coordinated approach to efficiently utilize funding, share expertise, and continue progress in horticultural technologies and breeding programs. Only then will the silent vegetable and horticultural revolution currently underway benefit a significant portion of the world’s poor nations, farmers, and landless laborers. Vegetables and fruits are grown worldwide and make up a major portion of the diet of humans in many parts of the world. They play a significant role in human nutrition, especially as sources of vitamins , minerals, dietary fiber and phytochemicals.Vegetables and fruits in the daily diet have been strongly associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke,chronic diseases such as diabetes, and some forms of cancer .Vegetable and fruit consumption worldwide is rising, reflecting the consumer’s increased income, desire of diversity, and awareness of nutritional benefits. A world vegetable survey showed that 402 vegetable crops are cultivated worldwide, representing 69 families and 230 genera. Leafy vegetables—of which the leaves or young leafy shoots are consumed—were the most often utilized , followed by vegetable fruits, and vegetables with below ground edible organs comprised 17%. Many vegetable crops have more than one part used. Most of the vegetables are marketed fresh with only a small proportion processed because most vegetables are perishable. Consumption shortly after harvest guarantees optimal vegetable quality.Vegetable and fruit production, due to their cultivation intensity, suffers from many biotic stresses caused bypathogens, pests, and weeds and requires high amounts of pesticides per hectare. Because of the high diversity of vegetable crops, pest loads vary and are complex vis-à-vis field crops. The main method for controlling pathogens,pests, and weeds has been the use of pesticides because vegetables and fruits are high-value commodities with high cosmetic standards. Synthetic pesticides have been applied to vegetable crops since the 1950s, and have been highly successful in reducing crop losses to some insects, other pathogens, and weeds. Vegetables account for a significant share of the global pesticide market. About 20% of the world’s annual pesticides expenditures are spent for growing vegetables . Only cotton used more insecticides than vegetables on an area basis. Insecticides are regularly applied to control a complex of insect pests that cause damage by feeding directly on the plant or by transmitting pathogens, particularly viruses. Despite pesticide use, insects, pathogens, and weeds continue to cause a heavy toll on world vegetable production. Preharvest losses are globally estimated as 15% for insect pests, 13% for damage by pathogens, and about 12% for weeds.

Pesticide residues can affect the health of growers and consumers and contaminate the environment. Vegetables are often consumed in fresh form, so pesticide residue and biological contamination is a serious issue.Consumers worldwide are increasingly concerned about the quality and safety of their food, as well as the social and the environmental conditions under which it is produced. Vegetable prices will therefore increase by enhancing their quality and safety .Transgenic crops, commonly referred to as genetically modified , crops enable breeders to bring favorable genes, often previously inaccessible, into already elite cultivars, improving their value considerably and offer unique opportunities for controlling insects and other pathogens. Many vegetable and fruit crops have been genetically modified to include resistance to insects, other pathogens , and herbicides and for improved features, such as slow ripening, higher nutritional status, seedless fruit, and increased sweetness. Recently,Dias and Ortiz  did a review  about the status of transgenic vegetables to improve their production. They analyzed the advances and potentials in transgenic research until 2010 on tomato,eggplant, potato, cucurbits, brassicas, lettuce, alliums, sweet corn, cowpea, cassava, sweet potato, and carrots.Some experimental transgenic vegetables show host plant resistance to insects, nematodes, fungi, bacteria, and viruses, extended shelf-life of the produce, herbicide tolerance, enhanced nutritional status, and seedless fruit and better flavor. Host plant resistance or product quality will increase the value of the vegetable throughout the chain, thereby benefiting farmers, traders and consumers. The most promising traits to reach vegetable and fruit growers seem to be host plant resistances to insects and other pathogens, especially for tomato, potato, eggplant,summer squash, sweet corn, papaya, plum and banana.Breeding transgenic pest resistant and herbicide tolerant vegetable cultivars can decrease management costs and release growers’ time for other economic activities, while also contributing to a less toxic production environment.Transgenic vegetables with tolerance to abiotic stresses or enhanced input efficiency could also provide various benefits to farmers and the environment, e.g. Bt cry genes could provide eggplants with host plant resistance to shoot borer while reducing today’s insecticide spraying during the crop season: 40 to 80 times in India or 50 times in the Philippines. Consumers could also benefit further from the use of more nutritioustransgenic vegetables, e.g. an increase of crop carotenoids by metabolic sink manipulation through a transgenic breeding approach appears feasible in some vegetable crops . Genetically engineering carrots containing increased calcium  levels may boost Ca uptake, thereby reducing the incidence of Ca deficiencies such as osteoporosis.Fortified transgenic lettuce with zinc will overcome its deficiency that severely impairs organ function.

Therefore disease resistance is most important when the disease is a limiting factor in production, and is especially important for many virus diseases. The high interest in, and the increasing present demand for breeding for disease and pest resistance is related to a generalized interest in releasing “environmentally friendly” vegetable cultivars requiring sparse or no use of pesticides. Breeding for post harvest traits, mainly transport quality, shelf life and cosmetic problems, is of increasing importance in vegetables. For example, in tomato, textural properties of fruits are important contributors to the overall quality for the fresh market and to the properties of products processed from tomatoes . Because cell wall disassembly in ripening fruit contributes to fruit texture, hydroponic channel modification of cell wall proteins and enzymatic activity during ripening can impact cell wall polysaccharide metabolism and influence texture.

Lettuce and other leafy vegetables used for salads deteriorate rapidly fol-lowing harvest, requiring a considerable investment of effort to maintain quality and shelf life of cut material. Harvesting increases respiration, stimulating deterioration, with increase in the synthesis of phenylalanine ammonia lyase and phenolic compounds, such as chlorogenic acid which cause tissue browning . Conse-quently, delaying leaf senescence is an important target for breeding of leafy vegetables. Also in lettuce, breeding efforts have targeted tipburn, marginal browning, and rib discoloration, which detract from overall appearance . Vegetable products with good transport quality, better shelf life and good appearance will be preferred by traders and also by consumers. Since vegetables are rich in vitamins, minerals and other micronutrients, and therefore vital for health, breeding objectives should include improving their nutritional value.

Historically vegetable breeders have applied selection pressure to traits related to agronomic performance, particularly yield and quality, because these are the traits important to the producer. Rarely have growers been paid for nutritional factors, so there have not been economic incentives to pay much attention to these traits. However,hydroponic dutch buckets consumers are becoming more aware of these traits . Vegetable breeding for nutritional quality was not mentioned as a primary goal in plant breeding text books through the mid-20th century.However vegetable breeding efforts targeting improved micronutrient content and composition had begun in the 1940s and 1950s with research describing the inheritance and development of tomato breeding stocks and lines high in provitamin A carotenoids and vitamin C . Lincoln et al.  noted a fourfold variation in vitamin C among commercial cultivars and up to 1194 ppm in red-fruited tomato interspecific crosses with Solanum pimpinellifo-lium.

Similar research leading to the development of darker orange, and consequently high provitamin A, car-rots began in the 1970s . Yellow core color occurs only in older open-pollinated carrot cultivars since uni-form orange storage root color has been a trait of interest in carrot for over a century . Similar studies were made in squash where rapid gains in carotenoid content have been made with phenotypic selection for orange color versus green and cream . Genetic improvement to increase levels of specific micronutrients has been pursued in several other vegetables such as melon, spinach, sweet potato, potato, lettuce, broccoli, pepper, watermelon, collard, kale, peas, and bean. This field of study is relatively new, and also complex because of mineral interactions with each other, and numerous other com-pounds in the soil and in the plant . There is usually a large environmental effect, when the component is present in tiny amounts, such as for some micronutrients and phytochemicals.

Success in vegetable breeding for higher vitamin and mineral content must consider not only substance concentration but also organic components in plants that can be abundant and either reduce or increase bioavailability.With these numerous considerations, breeding vegetable plants for improved nutritional value is a complicated goal that needs expertise in many disciplines such as plant breeding, nutrition, and soil science. When a vegetable compound  is found to be important for human health, and growers, vegetable markets and seed companies can capitalize on the value of the compound, there may be an opportunity for vegetable breeders to increase the amount of this compound. Breeders can be successful in reaching this goal, if the vegetable crop contains genetic variability for the com-pound, if selection is effective without detrimental pleiotropic effects, and if there is an easy method to measure the compound. Enhanced nutritional content would add value for poor, malnourished populations.

Vegetables make up about 35% of per capita food consumption in China, a much higher share than the world average . Besides India, other southern Asian countries such as Bangladesh, Cambodia, North and South Vietnam, Laos and Philippines are also high producers and great consumer of vegetables. For example, vegetables comprise 40% of the Bangladeshi diet . Many vegetables are consumed near where they are produced, especially in China, India and other Asian countries. The per capita consumption of vegetables in Asia has increased considerably from 41 kg to 141 kg between 1975 and 2003 , particularly in China where the per capita consumption has increased from 43 kg  to 154 kg . In Africa,grow table hydroponic the per capita consumption of vegetables lags far behind the world average, with less than the FAO/WFO  recommended minimum uptake of 200 g of vegetables/day .

Rapid growth in mean per capita incomes in developed countries during the 1990s enabled consumers to purchase a broader range of relatively expensive vegetable commodities such as off-season produce, relatively new or renewed vegetables and organic produce. Higher incomes of consumers in developed countries have also raised the demand for other attributes such as better quality vegetables and more variation in the daily menu. In developing countries, consumption and domestic vegetable markets are also expanding because of an emerging educated middle class with increasing incomes. China, India and Indonesia, countries with the largest populations, have large emerging middle classes, which impact the demand for high-value vegetables .

Al-though the overall downturn in the globally economy over the past decade has seen a decrease in the discretionary income of consumers in many countries. As a con-sequence the consumption of many high priced items such as fresh vegetables has been static or declining. This has also impacted on the rate of growth in exports from some countries. Globally, an increasing proportion of the world’s population is living in urban environments where their inter-est in and knowledge of farming, and therefore of food production, grow table is becoming increasingly deficient. In 1950 approximately 71% of the world’s population lived in rural locations while in 2010 this had declined to 50% , and is projected to be as low as 30% globally by 2050 . There is, in all developed countries, a growing expectation and dependence on the supply of a low-cost, year-round supply of premium quality vegetables.

Paradoxically, these same urban-based consumers have become increasing vocal about issues such as carbon taxes, the use of pesticides and safety of vegetables, labour conditions for farm workers, the sustainability of production methods, and the environmental conditions under which it is produced. These are often driven as “matters of conscience” and are in isolation from the reality of current production methods or of the opportunity to realistically meet these consumer demands. This trend, in turn, has led to the in- creased importance of organic vegetables and labeled brands . Most of the total organic arable land for vegetables  is located in Europe , fol-lowed by North America  and Latin America , but represents only 0.04% of the total area of vegetables in the world . Organic vegetable trade from developing to developed countries is currently growing at over 20% per year  but represents only 3% of total vegetable production .

Populations in developed countries are also shifting dramatically towards greater proportions of older people as a consequence of the “baby boom” of the 1940s and 1960s, and as a result of the lower birth rates in last re-cent decades. For example, in Japan and Europe , within twenty years many countries will face a situation where the largest population cohort will be those over 65 and average age will be approaching 50. These shifts are impacting strongly on consumer consumption patterns as evidenced by smaller households, increased dining out, and increased demands for healthier vegetabes and foods. Desire for year-round availability, increased diversity, and growing health awareness, have also been important reasons for increased consumption of vegetables in developed countries. For example, the dietary benefit of fresh produce, is the major reason for the 25% increase in fresh vegetable consumption in the United States during the 1977-1999 period . On the other hand, factors such as increased participation by women in the labor market have created demand for processed, ready-to-eat convenience vegetable products.Vegetables are purchased partly based on eye appeal, which means that the development of desire to consume, increases market demand. Diversification also tends to increase consumption.

A testing of four modeling methods  across 18 species with different levels of ecological specialization using six different sample size treatments and three different evaluation measures revealed that MAXENT was the most capable of the four modeling methods in producing useful results with sample sizes as small as 5, 10and 25 occurrences. MAXENT also predicted the largest area of all modeling methods at sample size 5 and remained fairly level at sample sizes of 25 and above . In the present study MAXENT was used to develop the model using very low sample size over a smaller area of 16,579 km² to predict the climatic suitability of the target species.

The model was able to bring out interesting insights on the climatic parameters which are playing an important role in the survival of the target species; the model defining precipitation as the most important predictor for the model grow lights. During field survey it was observed that occurrence areas are mostly hot and humid with high rainfall and the possibility of precipitation playing an important role in maintaining the population of the target specie sis quite relevant. The basic target for conservation works are on those species that are under high threat and those species in high threat category usually have low occurrence and it will be insignificant for conservationist unless working models are developed for these threatened species. In this study only climate data was used as our target species is plant species and climate plays a major role for its well being however, this does not negates the possibilities of anthropogenic and other biological factors contributing to the habitat loss and low occurrence of species.

The predication ability of the model with low sample size over a smaller area can be used to develop a mosaic of prediction models in areas where occurrence points are less and are in considerably distant pockets. Our study was able to give a success rate of 70%  with just4 sample over a small well defined area. Bottle gourd  originated in Africa and from there, it spread over the world . At present, it is grown in many countries including Bangladesh, India, Malaysia, Indonesia, Japan, China, The Philippines, Taiwan, Thailand, South Africa and Sudan . Bottle gourd fruits are used as cooked vegetables. Its leaves and tender stems are used as delicious and nutritious vegetables.Each 100 g bottle gourd contains protein1.1 g, carbohydrate 15.1 g, fat 0.1 g, minerals 0.6 g, and several vitamins .Bottle gourd is a popular winter vegetable in Bangladesh. The climatic condition of winter in Bangladesh favours better growth and yield of bottle gourd but hot and humid summer and summer rainy season gives poor yield. The average day temperature of 20˚C 27˚C with lower night temperature of 18˚C 23˚C is optimum for growth and fruiting.

Anthesis of flower in different cultivars is influenced by both temperature and rainfall. Bottle gourd is widely cultivated throughout the country. Its cultivation and uses are wide in winter season but nowadays it is cultivating during summer and rainy season. At present,led grow lights the acreage and annual production of bottle gourd are 7217 ha and 85,267 tons respectively in Bangladesh with an average yield of 11.81 tons per hectare ,which is very low compared to other countries.The identification and utilization of the most heterotic and useful crosses are very important in hybrid approach to make the commercial cultivation of hybrid beneficial . So a well-planned and dynamic bottle gourd breeding research programme is needed to meet the required demand of bottle gourd production.The understanding of the nature and magnitude of gene action is an important factor in developing an effective breeding programme. The diallel analysis provides an efficient means of rapidly obtaining an overall picture of the genetic control of a character in a set of parents in the early generations.

The analysis of combining ability helps in selecting suitable geno types as parents for hybridization and crosses for characterizing the nature and magnitude of gene action involved in quantitative traits . The use of contrasted lines in breeding programmes could contribute to create high yield varieties . On the other hand,plant selection for high yield can be effective only if the variables under selection have high heritability values . In Bangladesh context, the information on this aspect of bottle gourd is not sufficient. This study would be very important in developing hybrid varieties for Bangladesh conditions. Therefore, the present investigation was undertaken to investigate the genetic architecture of yield in bottle gourd. 

SSCM is defined as reformist SCM “which manages the material, information and capital flows as well as cooperation among companies along the supply chain while taking goals from all three dimensions of sustainable development, i.e. economic, environmental and social,into account which are derived from customer and stakeholder requirements”.The holistic view on sustainable supply chain management  coversenvironmental, economic and social aspects. SSCM as strategic,nft system transparent integrationand achievement of an organization’s social, environmental, and economicgoals in the systemic coordination of key interorganizational businessprocesses for improving the long-term economic performance of the individualcompany and its supply chains.

SSCM relates to the long-term improvement of organizations and has implications for companies’ economic bottom lines . The concept of SSCM is considered across the entire supply chain; the upstream, the focal organization and the downstream supply chain. In the upstream,the suppliers are considered while in the downstream the consumers and ultimately its disposal are taken in consideration. Environmental and social issues do not only affect the focal organization, but also other stakeholders across the entire supply chain. The organizations need sustainability not just for the sake of practicing but because it is a primary management principle that needsto be observed . At the intersection of the three dimensions of the TBL is thecore of sustainability and there are a number of activities that not only positively affect the environment and immediate society but also have positive economic implications on the organization.

There is a direct relationship between sustainability and TBL performanceoutcomes of the organizations . The application of Elkington’s TBL in SC ismeant to ensure that organizations operate sustainable supply chains . The aim of TBL is not to suggest that firms should identify and engage in social and environmental activities not likely to harm economic performance but instead it guides managers to identify activities which improve economic performance anddictates the avoidance of social and environmental activities that lie outside ofthe intersection . The application of TBL in supply chain is meant to ensurethat organizations operate sustainable supply chains. Horticulture sector being avery important sector in any economy in the world, it is therefore of essence thatthe sector to be self sustaining by adopting all the three dimensions of the TBLconcept.From the above literature review and studies,hydroponic gutter it was evident that there existedlittle on the TBL and most importantly none of existing study on Sustainabilityand TBL Performance in Food sector with specific interest of Horticulture. Figure1 presents the proposed conceptual framework.The study adopted a descriptive design to all the 25 registered horticulturalfirms in Nairobi. The data was collected by use of questionnaires that were administeredby drop and pick method. The questionnaires contained four sections. Section 1 sought data on firm profile, Section 2 had questionson environmental, social and economic variables, Section 3 sought data on thetriggers/drivers of Sustainability in Horticulture Sector; and Section 4 containedquestions on the relationship between SSCM Practices and TBL Performance.Two respondents were considered from each firm to participate in the study.The author was interested in the supply chain managers or its equivalent as therespondents from the twenty-five horticultural firms.

The data was sorted and coded accordingly to allow more appropriate analysisto be carried out. Frequencies were used to show both the firm profile and theextent to which horticultural firms have adopted TBL concept and sustainability of supply chain; factor analysis was used for triggers/drivers of sustainability and regression analysis was applied to explain the relationship between TBL and performance outcomes. Tables and histograms were also used to enhance outputpresentation. The authors successfully collected back 37 out of 50 questionnaires from therespondents thus representing a response rate of 74%. The authors sought information of the ownership of the horticultural firms inNairobi area and its environments and the responses showed that 75.7% are locallyowned while only 24.3% of the firms are foreign owned. It was also notedthat most of the firms were not too old as it is depicted by the number of years the firm has been in operation which, majority registered 54.1% being below 10years in operation and only 45.9% having operated in Nairobi Kenya for yearsspanning between 10 20 years. 86.5% of firms have employees of above 50 thus this confirms the need for sustainability and triple bottom-line.

Lake Sebu’s Municipal Agriculturist claimed that the Department of Agriculture provides farm inputs , farm equipment , farming seminars and trainings, and livelihood programs. These interventions are provided through farmers’ organizations. Free seedlings and fertilizers from the government are distributed by recognized farm organizations to their members. Farm equipment and implements such as thresher and corns heller, on the other hand, are given to the farm association and thus become communal properties of the members who are assigned schedules for use.Hence, only farmers who are members of a recognized farmers’ organization are able to avail of the government programs and support services.

There are many cases where farmers can not comply with the responsibilities and deliverables required of members and beneficiaries of government programs and assistance.For example,mobile grow rack farmers in far-flung, upland areas find it so hard to attend regular meetings and to comply with tedious reporting requirements and other protocols.Hence, not so many farmers are able to benefit from the government’s agricultural assistance program.Further, there are issues about the quality of farm inputs provided by the government.FGD participants revealed that corn seedlings from the government are not growing either because of poor quality and/or they are not suited for the soil chemistry in Lake Sebu.

The Municipal Agriculturist did not deny this claim of the farmers, but they argued that they have no control over the quality of the farm inputs as their office only depends on the provisions of the Department of Agriculture. The poor performance record of the farm inputs is another reason why many farmers in Lake Sebu are forgoing government assistance, particularly the free farm inputs program.In terms of infrastructure, five projects—three farm-to-market roads and two bridges—are soon to be completed in the Municipality as part of the Department of Agriculture’s Mindanao Sustainable Agrarian and Agriculture Development Program. These projects are expected to make the transport of farms products to market centers fast, safe and convenient, ebb and flow table thereby benefiting primarily the agricultural barangays . A look into the plight of farmers in the Municipality of Lake Sebu mirrors the conditions of low-productivity subsistence agriculture that is still prevalent in predominantly Muslim and indigenous people-inhabited areas of Mindanao in the southern Philippines  due to the twin constraints on sourcing and financing of farm inputs and on marketing of produce in the absence of a link with high-value markets .These twin constraints maintain the dominating presence of the middlemen that set high input prices and low farm-gate output prices.

First is a comprehensive logistics program that will expand farm-to-market road networks up to the far-flung and upland farms in Barangay Ned. The lack of roads necessitate the use of horses and motorcycles to bring produce from the uplands to the lowlands and the lack of internal connectivity result in double handling, food wastage, and failure of product consolidation, leading to higher per unit transport and handling costs.Because of these complicated and high logistics costs, Lake Sebu farmers prefer that traders pick up their produce and do not pursue higher prices by delivering their products directly to buyers. The three roads and two bridges project must just be the start of a complete farm-to-market infrastructure program.Second is a broad facilitation program for linking farmers and markets. Small farmers struggle to access inputs and output markets. Farm produce buyers, on the other hand, are having difficulty getting the quantity and quality of the produce they need on a consistent and timely basis. Government assistance in overcoming this market failure by bringing together buyers and producers is needed. Government must also provide support for the preparation and implementation of profitable business plans.This response can include investments and technical assistance for the formation of producers’ organizations or groups and for strengthening the organizational and entrepreneurial capacity of producer organizations, if they already exist.

Both at 60 and 75 DAS, Agrodhan-14 was the tallest cultivar which was followed by BRRI hybrid dhan3, and BRRI dhan28 was the shortest one which was at par with BRRI dhan59 and BRRI dhan50. At harvest, plant height ranged from 74.4 to 91.97 cm. Agrodhan-14 appeared as the tallest variety which was at par with Binadhan-6, and BRRIdhan50 was the shortest variety which was closely followed by BRRI dhan58.Weed infestation reduced plant height at all growth stages. The magnitude of reduction varied with growth phase, and reduction in plant height in weedy treatments followed a declining trend with advancement of crop growth. Presence of weeds markedly decreased plant height by 3, 16, 14, 3.5, 3.5 and 10% at15, 30, 45, 60, 75 DAS and harvesting time, respectively.

In case of interaction,dutch buckets for sale the tallest variety was Binadhan-6  which was followed by Agrodhan-14 in weed free condition at 60 DAS. The shortest variety was Binadhan-10 which was statistically similar with BRRI dhan50 in weedy condition and BRRI dhan28 and BRRI dhan59 in weed free condition . Relative yield loss is an excellent indicator of weed tolerance of a variety. Lower the relative yield loss, higher the degree of weed tolerance, since weed tolerance refers to the ability to maintain high yield in the presence of weed competition.The rice varieties showed wide diversity in relative yield loss, which ranged from43.4% to 82.1% . The relative yield loss was lowest in BRRI dhan59, followed by BRRI dhan67 and Binadhan-10 which exhibited high weed tolerance. The cultivars evaluated in this study varied not only in yield and weed suppressing ability, but also in all the agronomic traits measured.

Although a wide variation in traits was observed among cultivars, none of them gave satisfactory yield under aerobic conditions. Binadhan-5 emerged as the most productive, whereas BRRI dhan59 appeared as the most weed suppressive rice variety. The least productive cultivar was BRRI dhan55, which was closely followed by Binadhan-8and BRRI dhan58. Based on reports in earlier studies , the present study included a variety of commonly cited traits including plant height, tillering ability,early visual vigor, duration, and SPAD values. Significant variations among the varieties were recorded suggesting that selection based on those traits was practical.Plant height is considered as desirable characters for weed suppressive cultivars.Although plant height varied widely among the cultivars, early plant height i.e. height at 30DAS was strongly and negatively correlated with weed dry weight. Earlier and faster growth allowed the rice crop to compete with weeds for plant resources,hydroponic net pots and this was reflected in the crop yield. The results indicate that only early plant height can be considered as vital selection criteria for weed competitiveness under aerobic soil conditions. Similar type of results has also been reported by Gibson et al . , Caton et al . , Zhao et al . , Anwar etal . .Early visual vigor or vigor index, a reliable predictor of crop biomass integrating both height and tiller number, is an important selection criterion for weed competitiveness.

Yield and weed competitiveness are effectively predicted by early visual vigor. Vigor rating is rapid, non-destructive, less labor-intensive and reliable, and therefore a promising and feasible tool for making decisions on weed competitiveness. In this study, early visual vigor varied widely among varieties, and its strong correlation with other parameters confirms its acceptability.It has been reported previously that early season vigor is directly linked with the competitive ability of the crop and later in the crop growing season, it confers competition against weeds .The SPAD  meter provides a very easy, swift and non-destructive method for estimating relative leaf chlorophyll content.Higher SPAD values indicate greener healthier plants. The results showed SPAD values varied among the varieties.Weed interference negatively and markedly affected all yield components which cumulatively impaired grain yield. The rice varieties used in the current research showed wide diversity in relative yield loss, which ranged from 43% to 82%. Weed biomass was strongly and negatively correlated with grain yield, indicating that weed suppressive ability can be combined with yield potential. Anwar et al.  and McGregor et al.  also observed a similar relationship.

Also,nutrients are taken up from deeper layers by roots of trees and shrubs and returned to the top soil via litter fall and root senescence.Restoration of soil fertility by this means requires several years of fallow and has become inadequate in the face of increasing populations and food demand as well as competing alternative land uses. This has led to considerable reduction in the fallow period and the cultivation of marginal lands.In Sierra Leone, the uplands account for about 80% of the total arable land. The bush fallow system is a very common farming practice on the uplands of Sierra Leone although it is also practiced in almost all agroeclogies. Upland rice farming system involvesinter cropping rice with a variety of other crops such as cassava, maize, sorghum,sesame, pigeon pea, okra,hydroponic nft system garden egg, and other leafy vegetables. Rice normally occupies about 50% of the cropland .

Generally, the length of fallow period is reported to differ across the country with a mean of 8.8 years . In recent times, it is reported that the fallow period has dropped from the recommended period of ten or more years  to about 5 years in rural areas and 3 – 4 years along major highways .Apart from the FAO/UNDP survey in 1979 which estimated an average fallow period of 8.8, there has been very little work done to update information on length of fallow period in different parts of the country. There is lack of information on the current extent of reduction in fallow period in different parts of the country particularly in the eastern region of Sierra Leone which is home to the remaining rainforest of the country.The continued decline in the fallow period is a major threat to the persistence of the rainforest in the eastern region of Sierra Leone as farmers are tempted to slash-and- burn the remaining forest for upland rice farming. An understanding of the extent of reduction in fallow period in the Eastern Region of Sierra Leone will throw light on the magnitude of the problem and inform policy makers and land use planners to enable them develop intervention strategies to counteract the negative impact of the practice.

This study was therefore conducted to determine: 1) the extent of reduction of the fallow period in the Nongowa Chiefdom of Kenema District; 2) the causes of reduction in the fallow period; 3) farmers’ perception of the relevance of fallow period and the implications of reduction of fallow period on crop production. Sierra Leone is divided into four administrative blocks: the Provinces, nft channel the Districts, the Chiefdoms, and the Sections in decreasing sizes and administrative authority respectively.The study was conducted in four  Sections of the Nongowa Chiefdom: GboLambayama, Gbo Kakajama, Kagbado Kamboima and Dagbanya.The natural vegetation in these communities consists of secondary forest or farm bush with small trees or shrubs as a result of frequent felling of trees for farming. In each Section, a list of farmers practising slash-and-burn agriculture on the uplands was prepared and a total of twenty farmers were randomly selected from the list by balloting. In total, eighty farmers were randomly selected for the study in the four Sections of Nongowa Chiefdom. Farmers’ interviewed revealed that the reduction of the fallow period is affected by the general level of development of the community.

As the community grows in size, the corresponding increase in economic activities results in more land being used for settlements and construction of infrastructure. Additionally, the advent of investors coming to acquire land for large scale agriculture has led to less land becoming available for cultivation. Consequently, for the remaining portion of lands to which farmers have been confined, the fallow period becomes increasingly shortened or reduced and people begin to move from one community to another in search of lands that have fallowed long enough for crop cultivation. Human activities such as mining, logging and cutting down of forest trees for poles, fuel wood and charcoal production were also identified by farmers as competing alternative land use practices that have had serious effects on the farming communities in terms of land availability. Although historical evidence seemed to blame shifting cultivation for much of deforestation in the tropics , evidence from this study showed that other competing land uses such as mining, commercial agriculture, logging and charcoal production have a dominant effect in recent times.