Commercial Vegetable Production Research Articles

Comparison of chemigation versus foliar insecticide use: management of lepidopteran larvae and stink bugs in North Carolina field tomatoes with environmental and farmworker benefits

Commercial vegetable production in the United States of America (USA) often relies on foliar insecticide sprays for managing key insect pests. However, foliar applications of insecticides have a number of drawbacks to the health of consumers, farmworkers and the environment. Drip chemigation is the application of pesticides to the soil through trickle (drip) irrigation systems, and can overcome a number of the drawbacks typical of foliar insecticide applications. We conducted a two-year study in five commercial fields of staked tomatoes in western North Carolina to compare the efficacy, economics and environmental impact of drip chemigation versus foliar sprays. Drip chemigation significantly reduced insecticide inputs, utilized more selective and environmentally compatible insecticides, and reduced the time lost to reentry intervals, while maintaining comparable efficacy and economic returns. Drip chemigation was an effective tool for managing key insect pests, provided a broad range of human and environmental health benefits, and will likely become increasingly cost-effective in the future as insecticide patents expire and more insecticide options become available.

Micronutrient supplementation needs for halophytes in saline aquaponics with BFT system water

Saline aquaponics is a fast-growing research field, although little attention has been paid to micronutrients in water from aquaculture and their nutritional potential to sustain commercial vegetable production. This study evaluated the effects of micronutrient supplementation, direct in the water and by foliar spraying, against a no nutrient addition control, on growth and biomass production of the Brazilian halophytes Salicornia neei Lag., Apium graveolens L. and Paspalum vaginatum Sw., using saline aquaponics with one-year-old BFT system water from breeding stock tanks of the shrimp Litopenaeus vannamei. Plants were established in hydroponic units and clarified saline water from a BFT system was recirculated and replaced weekly over 30 days. Micronutrient addition in the water significantly increased the concentrations of iron, manganese and molybdenum, but water quality parameters and macronutrients were not modified. Micronutrient addition in the water increased P. vaginatum growth (shoot height and leaf number) and biomass production 20–30% compared to non-supplemented plants, showing the high micronutritional requirement of this species, most likely for iron. Salicornia neei plants showed no benefits when grown with the extra supply of micronutrients in the water, but a 73% reduction of shoot biomass occurred using foliar fertilization compared to the control treatment. Due to the poor development of A. graveolens plants, the response of this species to micronutrient additions could not be evaluated. Overall, clarified BFT system water can supply micronutritional requirements for halophytes, but supplementation may be necessary for species that have high demands and/or are more sensitive to the neutral-alkaline condition of marine aquaculture (e.g., impairment of Fe availability), such as P. vaginatum. Foliar spraying was not effective at improving halophyte growth, and caution should be taken when reusing water supplemented with micronutrients after it leaves an aquaponics system, due to the lack of knowledge about the toxicity of these added elements to animals.

Driving factors and impact of land-use change in a fragile rainfed lowland rice-sugar palm cultural agroforestry system in southern Thailand

The multi-functional agroforestry system associating rainfed lowland rice and sugar palm (RLR-SP) hedges has been sustaining emblematic cultural landscapes in the Indianized countries of Southeast Asia for centuries. Often established in areas facing very constrained soil–water conditions, it played a crucial role in the agro-ecological, social and economic resilience of these agrarian systems. Recent changes in communication infrastructure, commercialization, urbanization, state interventions and private initiatives have driven the transformations of these iconic cultural landscapes, but analyses of their socio-ecological impacts on household livelihoods and landscapes features are lacking. In this study, we quantified and analysed the transformations of a coastal RLR-SP cultural landscape in Southeast Thailand. We used remote sensing data to characterize and quantify land-use change during 1983–2015, and interviews with diverse stakeholders to understand the impacts of the driving factors of change on livelihood systems. After the mid-1980s, market integration facilitated by the construction of bridges and all-weather roads led to the diversification of farming and off-farm activities, increasing the mobility of farm labourers sizing wage-earning opportunities in neighbouring urban centres. In the 1990s, the RLR-SP system faced the introduction of an irrigation canal, shrimp farming, tree plantations, and the partial conversion of deep-water rice areas into mixed gardens. More recently, the demand for sugar palm fruits by the caning industry has revived an interest in sugar palm groves. A policy to raise the farm incomes associated with palm oil companies supported the conversion of paddy fields into small oil palm plantations, which is the most important recent land-use change and future threat to the survival of the RLR-SP system. Like in other Southeast Asian coastal areas, the increased frequency of extreme climatic events is another major threat faced by this emblematic but increasingly vulnerable cultural agroecosystem. The profitable and land/water resource efficient association of the RLR-SP system with commercial vegetable production on diversified smallholdings is a promising way towards a more sustainable landscape management that could be supported by improving on-farm water storage.

Factors influencing the adoption of urban commercial vegetable production in the Bangkok Metropolitan, Thailand

Factors influencing the adoption of urban commercial vegetable production in the Bangkok Metropolitan, Thailand

Factors influencing the adoption of urban commercial vegetable production in the Bangkok Metropolitan, Thailand

The objectives of this study were as follows: 1) to describe the socio-economic factors of urban dwellers who practise vegetable production; 2) to determine the factors influencing urban dwellers' adoption of urban commercial vegetable production (UCVP) in the Bangkok Metropolitan, Thailand. Questionnaires were administered to 134 respondents, who were randomly selected. A binary logistic regression model was employed to analyse the collected data. The results revealed that network membership and the practice of urban vegetable production has the potential to reduce the cost of buying vegetables and increase household income. The motivation that the consumption of urban vegetable products enhances people's health was found positively significant to the adoption of the UCVP practice. Moreover, the following factors were found to be negatively significant to UCVP practice adoption: access to information on urban vegetable production can also facilitate access to fresh vegetables and practising vegetable production as a recreational activity.

Effects of seed bed types and weed control methods on the vegetative parameters of long cayenne pepper (Capsicum frutesens L)

Effects of seed bed types and weed control methods on the vegetative parameters of long cayenne pepper (Capsicum frutesens L)

Chapter 1: Introduction

This document is HS710, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date June 1995. Revised November 2006. HS710/CV100: Chapter 1. Commercial Vegetable Production in Florida (ufl.edu)

Contribution of integrated forest-farm system on household food security in the mid-hills of Nepal: assessment with EnLiFT model

ABSTRACTAbout half of the households in the mid-hills of Nepal are severely food insecure, and the development of agriculture and forestry sectors could hold keys to reduce food insecurity and achieve other sustainable development goals. This paper presents results from a bio-economic model, Enhancing Livelihood from Improved Forest Management in Nepal (EnLiFT), that estimates a Food Security Index (FSI) across six household types in rural Nepal simulating selected agroforestry livelihood interventions. The FSI is calculated as the ratio between household expenditure capacity and household poverty threshold based on the national per capita poverty threshold. Market-oriented timber production shows strong potential to increase food security across all household types with greater benefits accruing to land-rich households. For land-poor households, remittances from household members working abroad remains the strongest route to their food security despite the underutilisation of agricultural land due to adult male labour outmigration. A drawback of market-oriented timber production is the long-term nature of timber production. As EnLiFT assumes that timber can only be harvested from Year 9, complimentary livelihood strategies are required to address food insecurity in the short term. Complimentary agroforestry interventions with the strongest potential to improve food security include combined high-yielding fodder production and commercial goat production, and production of non-timber forest products. Commercial vegetable production does not improve food security because of the high input costs. Currently, farmers in Nepal cannot yet fully obtain the financial benefits of agroforestry due to the complex and unsupportive forestry regulations surrounding harvesting and marketing of planted trees. While land-poor households are seen to rely on foreign remittances for food security, it is argued that policies encouraging use of remittances to promote agroforestry businesses is needed.

Differential Biomass Accumulation among African Leafy Vegetables as Affected by Wastewater Irrigation in Kitui County, Kenya

Water scarcity of fresh water in Sub-Saharan has led to utilization of the wastewater in home gardening and also in commercial production of vegetables. Wastewater is associated with various substances including nutrients and heavy metals hence it is pertinent to evaluate its effects on growth and yield of vegetables. An experiment was conducted to evaluate the effect of waste water released from the municipal council on the biomass accumulation in African leafy vegetables. Field experiments were carried out in two seasons and one greenhouse experiment. The field trial was laid out in a Randomized Complete Block Design (RCBD) and in the greenhouse the treatments were arranged in Complete Randomized Design (RCD) replicated three times. Four leafy vegetables were the treatments replicated three times. The vegetables were irrigated with waste water. Plant samples were collected at 6 WAP and 12 WAP, partitioned and dried in an oven and later weighed using electronic weighing balance. The findings revealed differences in biomass accumulation into various organs. Black nightshade depicted the highest leaf dry matter in the greenhouse at both 6 weeks after plant (WAP) and 12 WAP (24.62 g and 81.12 g respectively). Cowpea showed the highest increment (7 folds) in leaf weight between 6 to 12 WAP as compared to was paltry 3.6 folds. The highest stem dry weight was obtained in the amaranth species at 6 WAP and 12 WAP both in the greenhouse; recording 32.59 g and 90.12 g respectively. A similar trend was noted in root dry weight and root: shoot ratio. Cowpea had the least biomass accumulation potential across all the parameters in both seasons and in the greenhouse. The increased biomass growth is an indication sufficient availability of nutrient that promoted vibrant plant growth and also less toxicity from the heavy metals. Therefore, waste water can be put into use to enhance improved productivity of African leafy vegetables.

2018 Vegetable Production Handbook Chapter 1: Commercial Vegetable Production in Florida

This 2-page fact sheet is chapter 1 of the 2018 Vegetable Production Handbook. The objective of this publication is to provide updated information on crop cultivars, pesticide labels, and certain practices for vegetable production in Florida. Suggested practices are guidelines for growers to plan farm activities and are always subjected to review using the latest scientific data available. Written by Josh H. Freeman, Peter J. Dittmar, and Gary E. Vallad, and published by the Horticultural Sciences Department, 2018. HS710/CV100: Chapter 1. Commercial Vegetable Production in Florida (ufl.edu)

Increased percentage of fruit set of F1 hybrid of Capsicum chinense during high-temperature period

Low percentage of fruit set in fruit vegetables cultivated in greenhouses, such as tomato (Solanum lycopersicum), eggplant (S. melongena), and capsicum (Capsicum), in high-temperature seasons has been reported as one of the biggest problems in commercial vegetable production. In this study, C. chinense ‘Sy-2’ and ‘No. 3686’ were cultivated in greenhouses for a year. Remarkably low percentages of fruit set (3.2% and 0%, respectively) were obtained in the high-temperature season (40 °C/25 °C: day/night). However, the percentage of fruit set was recovered with the decrease in temperature in autumn and winter (30 °C/20 °C). On the other hand, in F1 (‘Sy-2’ × ‘No. 3686’), the percentage of fruit set was 40.8% even in the high-temperature season. On in vitro pollen germination test, the pollen of F1 was found to have a higher germination rate than that of ‘Sy-2’ or ‘No. 3686’ during the high-temperature season. After ‘Sy-2’ was cross-pollinated with ‘Sy-2’ and ‘No. 3686’ pollen, percentages of fruit set were 23.3% and 0%, respectively. It is noteworthy that the cross-pollination of ‘Sy-2’ with F1 pollen resulted in a considerably higher percentage of fruit set (73.3%). When F1 was self-pollinated, the percentage of fruit set (56.7%) was higher than that after when cross-pollinated with ‘Sy-2’ or ‘No. 3686’ pollen. Interestingly, no fruit set was obtained when ‘No. 3686’ was cross-pollinated with ‘Sy-2’, ‘No. 3686’, or F1 pollen. The results for ‘No. 3686’ indicated that not only does the male factor affect pollen germination ability but also unknown female factors are involved in reducing the percentage of fruit set of C. chinense under the high-temperature season. A significant increase in the percentage of fruit set in the high-temperature season was also observed in the reciprocal cross of F1, ‘No. 3686’ × ‘Sy-2’. Furthermore, 10 plants of (‘No. 3686’ × ‘Sy-2’) × ‘Sy-2’ and 31 plants of ‘Sy-2’ × (‘No. 3686’ × ‘Sy-2’) were cultivated in a greenhouse, but no difference was found in the percentage of fruit set between these two combinations. Therefore, our findings suggest that cytoplasmic factor(s) does not influence the percentage of fruit set.

Effect of soil edaphic factors on Rhizoctonia solani mediated diseases in major vegetable brassica growing districts of West Bengal

Gangetic alluvial region is the most fertile part of West Bengal where majority of farmers' livelihood is commercial vegetable production. Vegetable brassica such as cabbage, cauliflower and radish occupies 18 per cent of total vegetable cultivation in West Bengal and mainly cultivated in Nadia, Mursidabad, Purulia, North 24 praganas and South 24 praganas districts. Damping off, wire stem and root rot are the major diseases caused by Rhizoctonia solani in these districts. Different soil edaphic factors like soil temperature, soil pH, available carbon, available nitrogen etc. play a major role in survival and spread of Rhizoctonia solani and hence, this study was undertaken. The survey reveals that among different soil edaphic properties; soil pH, organic C and available N (kg/ha) are the important determinants of disease conduciveness and suppressiveness. Soil pH is the most important determining factor for disease development. The disease incidence is negatively correlated with the pH.

The dynamics of smallholders’ participation in the commercialization of high-value horticultural crops: a case of vegetable producers in Kenya

The high-value horticultural markets in Kenya were for a long time one of the best examples of how smallholders are able to participate in globalized food-market systems. However, participation of smallholders in these markets seems to have been declining over the recent past. This study exploits panel data of households from selected vegetable-producing regions in Kenya, in order to examine the dynamics of smallholders' participation in the commercialization of high-value vegetable crops. Results show that the number of smallholders participating in commercialization of vegetables is indeed declining. Key constraints are related to high costs of production, low and fluctuating market prices, stringent market regulations and insufficient water for irrigation. Farmers exiting from vegetable markets have significantly older household heads and they own less agricultural assets and livestock than farmers who continue to engage in the commercial production of vegetables. Policy interventions should focus on promoting the development of marketing infrastructure and institutional support for smallholders to be able to commercialize through export and domestic market channels.

Optimizing expenditures for agricultural land conservation: Spatially-explicit estimation of benefits, budgets, costs and targets

This paper presents an empirical analysis of the optimal use of financial resources for agricultural land conservation in the Alberta Capital Region, Canada. All elements of the analysis are spatially explicit, including estimation of benefits and budgets from a choice experiment with Capital Region residents, assessed farmland value and list price data on conservation costs, and priority targets for conservation. The performance and efficiency of four targeting criteria are evaluated and compared for alternative budgets that are derived from the benefit study, applied to two sets of data on costs. The results show considerable interest in farmland conservation in the Alberta Capital Region: we estimate that a one-time increase in property taxes or rent that would generate $CAD 17.6 million would be acceptable to 75% of the population. Willingness to pay for conservation was highest for land used for commercial vegetable production, located near to primary highways and outside of city limits. However, the difference in willingness to pay to conserve such land generally does not offset the higher costs of that type of land, and efficient use of limited conservation funds would result in the targeting of lower-cost grazing lands located further from the main population centres. As expected, the branch-and-bound optimization (OPT) and benefit-cost ratio targeting (BCRT) provide more efficient use of conservation funds than either benefit targeting (BT) or cost targeting (CT).

Clubroot – An Emerging Disease Faced by Czech Oilseed Rape Growers

AbstractClubroot is caused by the pathogen Plasmodiophora brassicae Woronin and has become a serious problem in oilseed rape production in the Czech Republic. The disease was previously widespread in commercial vegetable production and in hobby gardens. Whereas previously restricted only to the NE, since 2010 oilseed rape clubroot has been spreading across the whole country. A five-year monitoring of clubroot occurrence based on disease symptoms detection on oilseed rape fields was accomplished by the Union of Oilseed Growers and Processors. The presence of P. brassicae and clubroot symptoms was reported in all regions of the Czech Republic, except the Ústecký region, and in 31 out of 76 districts. At present, at least 130 fields are known to be infested by the pathogen, but this number is very likely underestimated. Some soil samples were also tested using the conventional polymerase chain reaction (PCR) method to evaluate the soil usability. All 14 suspected samples tested positive.

Plastic mulch and nitrogen fertigation in growing vegetables modify soil temperature, water and nitrate dynamics: Experimental results and a modeling study

Plastic mulch in combination with drip irrigation present a common agricultural management technique practiced in commercial vegetable production. This management can result in various impacts on water and nutrient distribution and consequently affect nutrient dynamics in underlying soil. The aim of this work was to: (i) compare the effects of different mulching types (color) on soil temperature and (ii) crop growth; (iii) estimate the effect of plastic mulch cover (MULCH) on water and (iv) nitrate dynamics using HYDRUS-2D. The field experiment was designed in the Croatian coastal karst area on main plots with three levels of nitrogen fertilizer: 70, 140, and 210kgha−1, which were all divided in five subplots considering mulch covering with different colors types (black, brown, silver, and white) and no covering (control). Monitoring of water and nitrate dynamics was performed through lysimeters which ensured input data for HYDRUS-2D model. The experimental results showed that plastic mulch had a significant effect on soil temperature regime and crop yield. The dark color mulch (black, brown) caused higher soil temperature, which consequently enabled earlier plant development and higher yields. HYDRUS-2D simulated results showed good fitting to the field data in cumulative water and also nitrate outflow. Water flow simulations produced model efficiency of 0.84 for control (CONT) and 0.56 for MULCH systems, while nitrate simulations showed model efficiency ranging from 0.67 to 0.83 and from 0.70 to 0.93, respectively. Additional simulations exposed faster transport of nitrates below drip line in the CONT system, mostly because of the increased surface area subjected to precipitation/irrigation due to the absence of soil cover. Numerical modeling revealed large influence of plastic mulch cover on water and nutrient distribution in soil. The study suggests that under this management practice the nitrogen amounts applied via fertigation can be lowered and optimized to reduce possible negative influence on environment.

Practices to Minimize Flooding Damage to Commercial Vegetable Production

Flooding is a major risk for commercial vegetable production in south Florida, especially in the south Dade County area. Flooding causes oxygen deficiency, or hypoxic stress, causing the plants to produce less energy. This shortage in energy prevents the absorption of nutrients like nitrogen, phosphorous, and potassium. This revised 4-page fact sheet discusses several different management practices for overcoming flood damage, including the use of nitrogen and potassium fertilizers, oxygen fertilizers, growth regulators, and fungicides. Written by Goudong Liu, Yuncong Li, and Xiangju Fu, and published by the Soil and Water Science Department, December 2015. SL 206/SS425: Practices to Minimize Flooding Damage to Commercial Vegetable Production (ufl.edu)

Site selection for catch crop processing facilities

For efficient biomass collection and transportation, it is important to determine the optimal locations for processing facilities, which are strongly affected by the geographical distribution of biomass in a given region. This study focused on identifying optimal locations, considering changes in the distribution of the available biomass. We developed a methodology to select the optimal locations for processing facilities based on minimizing transportation and on the biomass availability in a given region. The methodology was applied to selecting optimal locations for catch crop utilization; catch crops are vegetation grown in the fallow period of commercial vegetable production to absorb excess nutrients from the soil. The results of this study demonstrate a shift in the optimal location from the eastern part of the study area to the central part in the event of an increase in available biomass in the western region. In the case of two facilities, no shift was evident and the locations stabilized in the western and eastern parts of the central region of the study area. We evaluated these results within the context of transportation cost, transport distances, and the collected volume of catch crop. The methodology that we developed is relatively simple and easily applied to the collection of other biomass resources.

A rootstock provides water conservation for a grafted commercial tomato (Solanum lycopersicum L.) line in response to mild-drought conditions: a focus on vegetative growth and photosynthetic parameters.

The development of water stress resistant lines of commercial tomato by breeding or genetic engineering is possible, but will take considerable time before commercial varieties are available for production. However, grafting commercial tomato lines on drought resistant rootstock may produce drought tolerant commercial tomato lines much more rapidly. Due to changing climates and the need for commercial production of vegetables in low quality fields there is an urgent need for stress tolerant commercial lines of vegetables such as tomato. In previous observations we identified a scion root stock combination (‘BHN 602’ scion grafted onto ‘Jjak Kkung’ rootstock hereafter identified as 602/Jjak) that had a qualitative drought-tolerance phenotype when compared to the non-grafted line. Based on this initial observation, we studied photosynthesis and vegetative above-ground growth during mild-drought for the 602/Jjak compared with another scion-rootstock combination (‘BHN 602’ scion grafted onto ‘Cheong Gang’ rootstock hereafter identified as 602/Cheong) and a non-grafted control. Overall above ground vegetative growth was significantly lower for 602/Jjak in comparison to the other plant lines. Moreover, water potential reduction in response to mild drought was significantly less for 602/Jjak, yet stomatal conductance of all plant-lines were equally inhibited by mild-drought. Light saturated photosynthesis of 602/Jjak was less affected by low water potential than the other two lines as was the % reduction in mesophyll conductance. Therefore, the Jjak Kkung rootstock caused aboveground growth reduction, water conservation and increased photosynthetic tolerance of mild drought. These data show that different rootstocks can change the photosynthetic responses to drought of a high yielding, commercial tomato line. Also, this rapid discovery of one scion-rootstock combination that provided mild-drought tolerance suggests that screening more scion-rootstock combination for stress tolerance may rapidly yield commercially viable, stress tolerant lines of tomato.

Purple Nutsedge Control with Allyl Isothiocyanate under Virtually Impermeable Film Mulch

Nutsedge control is challenging in commercial vegetable production in the absence of methyl bromide, and therefore, an effective alternative is needed. This study investigated allyl isothiocyanate (ITC) as a methyl bromide alternative for purple nutsedge control under polyethylene-mulch. Greenhouse experiments were conducted to compare the retention of allyl ITC in treated soil (3,000 nmol g−1) under low-density polyethylene (LDPE) and virtually impermeable film (VIF) mulches. Field experiments were conducted to evaluate the effectiveness of allyl ITC (6 rates: 0, 15, 75, 150, 750, 1500 kg ai ha−1) under VIF mulch against purple nutsedge. Additionally, a standard treatment of methyl bromide+chloropicrin (67 : 33%) at 390 kg ai ha−1under LDPE mulch was included for comparison. In the greenhouse experiment, the predicted half-life of allyl ITC under LDPE and VIF mulch was 0.15 and 0.59 d, respectively. In the field experiment, it was predicted that allyl ITC at 1,240 and 1,097 kg ha−1under VIF mulch is required to control purple nutsedge shoot and tubers equivalent to methyl bromide + chloropicrin at 4 wk after treatment (WAT). It is concluded that allyl ITC under VIF mulch would need to be applied at 2.8 to 3.2 times the standard treatment of methyl bromide + chloropicrin under LDPE mulch for commercially acceptable purple nutsedge control.