Vegetable Agroecosystems Research Articles

The impact of biologically enhanced fertilisation systems on sweet potato (Ipomoеa batаtas) productivity and quality

The relevance of this research lies in determining the potential use of microbial preparations with varying functionalities to optimise the nutrition and stimulate the growth processes of sweet potato plants, as well as the synergistic effects of different preparations. The developed nutrient optimisation systems are designed to restore soil fertility, reduce the anthropogenic load on vegetable agroecosystems, produce high-quality yields, and increase sweet potato productivity without relying on energy-intensive production methods. This study aimed to investigate the impact of biological fertilisation systems on the biometric parameters, yield, and quality of sweet potato tubers. The research programme was implemented through field, statistical, computational-analytical, and laboratory methods. An increase in the number (7.33-9.83 per plant) and length (175.55-184.89 cm) of shoots was observed with the application of the biological preparations “Groundfix” + “Humifriend”, “Help-Rost for vegetables”, and “Mycofriend”. The use of foliar fertilisations in three terms of “Help-Rost for vegetables”, both in combination with “Mycofriend” during fertigation and with the foliar fertilisation “Humifriend”, resulted in maximal leaf mass formation on the plant (2.41-2.56 m2 /ha in the third decade of June and 23.12-27.45 m2 /ha in the third decade of August). Microbial preparations significantly increased net photosynthetic productivity by 28.9-63.9% during the period from the third decade of June to the third decade of July, especially when “Groundfix” and “Humifriend”, or “Humifriend” and “Help-Rost for vegetables” were combined. A substantial commercial yield of tubers (17.4 t/ha) was achieved by applying the mycorrhizal preparation “Humifriend” (1.5 L/ha) in the first fertigation and conducting three foliar applications of “Help-Rost for vegetables” at 2.0 L/ha. Treatments involving biological preparations demonstrated improvements in key biochemical parameters. The use of “Groundfix” + “Humifriend” and “Humifriend” + “Help-Rost for vegetables” resulted in a decrease in nitrate levels in the produce. The authors hypothesise that the optimal supply of micronutrients, particularly iron, manganese, and molybdenum, enhances the transformation of nitrates into organic matter. This research provides valuable insights for the rational application of biologically enhanced fertilisation systems to achieve high yields and quality of sweet potato tubers in various agricultural settings

Three years of cover crops management increased soil organic matter and labile carbon pools in a subtropical vegetable agroecosystem

AbstractCover crops have been widely adopted to improve soil functions in agroecosystems, including providing carbon (C) inputs that can contribute to soil C sequestration. However, soil C changes may be slow after introducing cover crops in unfavorable environments for soil organic matter (SOM) accumulation, like the Southeast United States subtropical region characterized by a warm humid climate, and coarse‐textured soils. We examined labile C pools as potential early indicators of SOM changes after cover crop introduction in a sandy subtropical vegetable production system. We compared the effects of four cover crop monocultures namely two grasses [sorghum sudangrass, Sorghum bicolor × S bicolor var. Sudanese and pearl millet, Pennisetum glaucum (L.) R. Br.], two legumes (sunn hemp, Crotalaria juncea L., and cowpea, Vigna unguiculata Walp.), and one four‐species mixture on soil organic carbon pools for 3 years. Soil samples were collected at a 15‐cm depth before cover crop planting and post cover crop incorporation to assess changes in SOM, permanganate‐oxidizable carbon (POX‐C), mineralizable carbon (Cmin), and water extractable organic carbon (WEOC). The incorporation of cover crops increased concentrations of SOM, POX‐C, and Cmin in year 3 relative to their baseline values in year 1. Concentration of SOM increased by 0.24 ± 0.05% (mean ± standard error) after 3 years of cover crop management. However, concentrations of WEOC significantly decreased in years 2 and 3 relative to the baseline. Monocultures and the mixture had similar effects on measured C pools, likely due to comparable aboveground biomass production. Our findings highlight the potential of POX‐C and Cmin as early indicators of SOM accumulation driven by cover crops use, as well as the capacity of cover crops to build SOM in similar subtropical systems and coarser textured soils.

Contrasting roles of landscape compositions on shaping functional traits of arthropod community in subtropical vegetable fields

Agricultural intensification and land use transformation are among the main driving forces of the unprecedented decline of biodiversity and ecosystem services in croplands. Trait-based approaches provide a unique framework to detect the potential mechanisms of how this intensification affects biodiversity and alter ecosystem services. However, the potential relationship between arthropod traits and various types of habitats is still poorly understood, especially in subtropical vegetable agroecosystems. Here, we conducted a trait-based approach to evaluate the variable roles of different habitats on functional trait diversity and the structure of the arthropod community in brassica vegetable crops. Twenty-three conventional cruciferous vegetables fields were sampled over two years in three regions in Fujian, China. We found that the increasing proportion of non-brassica vegetable plantations and water bodies negatively affected the functional diversity of arthropods, whereas forest and grassland habitats showed a positive correlation, indicating habitat filtering for certain traits or trait combinations. This study demonstrates the importance of landscape composition as an ecological filter for vegetable arthropod community, and identifies how the proportion of different habitats selected for or against specific functional traits. Our findings support that increasing forest and grassland areas adjacent to vegetable fields can play a vital role in promoting the functional diversity of arthropod communities. Since the natural enemy assemblages supported by these habitats bear combinations of diverse traits adapted to disturbance, they have the potential to enhance pest suppression in the highly variable environment of vegetable crops.

Optimizing control of flea beetles through ecological engineering of vegetable agroecosystem in Kashmir

Ecological engineering is a concept of habitat manipulation to reduce dependence on insecticides. It is the intentional involvement of plant communities and insectary plants in managed landscapes influencing natural enemies survival. These natural enemies lead to reduction in pest population in environmentally acceptable production practices. Field experiments were conducted during 2019 and 2020 to evaluate impact of ecological engineering on the flea beetles, P. striolata and A. himensis and their natural enemies on brinjal crop. Three treatments with different plant species were worked out for pest management study. Results showed that Treatment I caused maximum increase in mean number of natural enemies (1.11/ 10 plants) which in turn brought maximum mean pest reduction. Treatment II caused second maximum increase in mean number of natural enemies (0.92/ 10 plants). Treatment III caused minimum increase in mean number of natural enemies (0.68/ 10 plants). The diversity of predators was documented in different treatments. Simpson’s diversity index, Shannon-Weiner index and Evenness index were found higher in Treatment I followed by Treatment II and Treatment III. The maximum mean % increase of natural enemies in main crop over control (250.52 %) with maximum mean % reduction of target pest (63.46 %) was observed in Treatment I. The mean % increase of natural enemies in main crop over control (167.44 %) with mean % reduction of target pest (54.41 %) was observed in Treatment II. The mean % increase of natural enemies in main crop over control (20.97%) with mean % reduction of target pest (48.88%) was observed in Treatment III.

Dynamic of migration and labor productivity in the rural area of PATANAS villages

The agricultural sector still becomes a source of household income in rural areas, although its role tends to decrease. In the period 2011‒2015, the number of agricultural workers decreased about 1% per year and is inversely proportional to the increasing Indonesian labor, which reached an average of 1.2% per year. Several leading causes of labor decreases are migration and productivity issues in the agricultural sector. This paper aims to determine migration and labor productivity dynamics in three-time points in villages on Panel Petani Nasional Program (PATANAS) located at three agroecosystems: plantation, secondary crop, and vegetable. Amount of respondents in each agroecosystem were 312, 232, and 121 farmers. Data analysis was presented descriptively. The results of the study indicated that labor productivity varies between agroecosystems. The highest increase in productivity occurred in vegetable, then secondary crop, and plantation. Labor productivity in the agricultural sector is inversely proportional to the migration on an agroecosystem. There is not excessive migration in the vegetable agroecosystems since labor productivity is highest than the others. There is a phenomenon of increasing working family members followed by an increase in the number of migrations. This phenomenon negatively impacts the agricultural sector because there is no increase in the number of workers in the agricultural sector. There is a trend for young people in PATANAS villages to undertake permanent migration. Increasing labor productivity in rural areas predicted could reduce labor migration. Efforts that can be created are gradually encouraging off-farm and non-farm activities, including small-scale agro-industries.

An inventory of moths in the vegetable agroecosystems of northern kerala

An inventory of moths in the vegetable agroecosystems of northern kerala

Calneem: A commercial neem seed-based biopesticide for sustainable management of pests of vegetables in Ghana

The production of vegetable crops is a major agricultural activity of small and medium-scale farmers in Ghana and has a greatpotential to increase the income levels growers. However, vegetable production is constrained among other factors by attackby insect pests, diseases, nematodes and the declining soil fertility, necessitating the use of pesticides and artificial fertilizers.Currently, the main method of controlling pests and diseases of vegetable crops is the use of synthetic pesticides. This paperexamines the environmental, food safety, health and other problems inherent in the dependency on conventional pesticidesto control crop pests in Ghana and advocates the need to develop a sustainable and environmentally sound alternative pestmanagement strategy using neem pesticides as the major component. Native to India and Burma, the neem tree, Azadirachataindica A. Juss was introduced to Africa earlier this century and is now well established in at least 78 countries, including Ghanawhere it has become an important source of fuel, lumber and biopesticides. Neem products are broad spectrum bio-pesticideswhich are effective against several pests of vegetables, food crops, fruit and other tree crops. Using the results of extensive fieldtrials conducted in two locations in the Greater Accra Region of Ghana, the paper would demonstrate the practical utilization ofCalneem oil and Neem seed extract for sustainable protection of okra and cucumber against pest infestation in Ghana. It wouldalso show that neem pesticides are less harmful to some beneficial organisms in the vegetable agro-ecosystem such as certain antspecies, lady bird beetles, dragon flies and other predators. Practical challenges to widespread application of neem bio-pesticidesfor sustainable crop protection in Ghana are discussed.

The Effect of Conservation Tillage and Cover Crop Residue on Beneficial Arthropods and Weed Seed Predation in Acorn Squash.

Conservation tillage combined with cover crops or mulching may enhance natural enemy activity in agroecosystems by reducing soil disturbance and increasing habitat structural complexity. In particular, weed seed predation can increase with vegetation cover and reduced tillage, indicating that mulches may improve the quality of the habitat for weed seed foraging. The purpose of this study was to quantify the effects of tillage and mulching for conservation biological control in cucurbit fields. The effects of mulch and reduced tillage on arthropods and rates of weed seed loss from arenas were examined in field trials on sandy soils in 2014 and 2015. Experimental factors included tillage and cover crop, each with two levels: strip-tillage or full-tillage, and cover crop mulch (rye residue) or no cover crop mulch (unmulched). Arthropod abundance on the crop foliage was not affected by tillage or cover crops. Contrary to expectations, epigeal natural enemies of insects and rates of weed seed removal either did not respond to treatments or were greater in full-tilled plots and plots without mulch. Our study demonstrates the potential importance of weed seed predators in reducing weed seedbanks in vegetable agroecosystems, and suggests that early-season tillage may not be detrimental to epigeal predator assemblages.

English

Begomoviruses are the important pathogens of variety of crop plants and are responsible for causing huge economic losses. It is assumed that cotton vegetable agro eco system plays a vital role in the complex etiology of the diseases caused by begomoviruses. Therefore, the present work was planned to study the relationship among begomoviruses infecting cotton, chilli, radish, tomato and papaya. For this purpose, the symptomatic leaves of these plants were collected and were processed for DNA isolation. The amplified coat protein gene of begomoviruses was cloned and sequenced. The phylogenetic analysis showed that begomoviruses infecting cotton are totally different from the begomoviruses infecting other crops. Based on the coat protein gene sequences, the viruses infecting cotton were identified as cotton leaf curl virus, chilli leaf curl virus in chilli, radish leaf curl virus in radish, tomato leaf curl virus in tomato and papaya leaf curl virus in papaya. Key words: Begomovirus, cotton, vegetables, variability.

Hymenopteran Parasitoids Diversity Associated with Organic and Coventional Agroecosystems in West Sumatera, Indonesia

The use of pesticides in agricultural ecosystems does not only cause environmental pollution, but also impovert diversity of natural enemies such as parasitoids and predators as well as causes the emergence of pests resistance to pesticides. The study was focused to identify and compare the abundance, diversity and evenness of Hymenopteran parasitoid species in organic and conventional agroecosystems. This research was conducted in several organic and conventional vegetable agroecosystems in West Sumatera. The tools used for the collection of insects were farmcop, sweep net and yellow pan traps. A total of 717 individuals of Hymenopteran parasitoids belonging to 21 families and 131 species were recorded during the study. A total of 533 individuals collected in organic agroecosystem consisted of 20 families and 85 species of Hymenopteran parasitoids, whereas in conventional agroecosystems there were 184 individuals collected cosisted of 13 families and 46 species of Hymenopteran parasitoids. This study also demonstrated a strong relationship between crops and Hymenopteran parasitoid composition. Species diversity and evenness of Hymenopteran parasitoids were higher in organic than in conventional agroecosystems.

Seasonal changes in soil microbial biomass under different agro-ecosystems of Arunachal Pradesh, North East India

The study was carried out to investigate the soil microbial biomass C, N and P of major agro-ecosystems prevalent in East Siang district, Arunachal Pradesh viz., Soybean, Millet, Maize and Vegetable agro-ecosystem. The study was conducted for a period of an annual cycle during the year 2010-11. Microbial biomass C and N ranged between 199.61 and 238.35 μg g -1 and 15.46 and 26.55 μg g -1 respectively. It was found to be higher in the surface soil layer than the subsurface layer in all the agro-ecosystems. Microbial biomass P significantly varied among the seasons and sites (P DOI: http://dx.doi.org/10.4038/jas.v8i3.6087 The Journal of Agricultural Sciences, 2013, vol.8, no3 p. 142-152

Host preference of Lysiphlebus testaceipes (Hymenoptera: Braconidae, Aphidiinae), an alien aphid parasitoid in Benin

Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae) is a newly discovered species alien to Benin (West Africa) and the dominating aphid primary parasitoid in vegetable agroecosystems. A study on the preference of this parasitic hymenopteran for three key aphid pests of vegetables (Aphis craccivora Koch, Aphis gossypii Glover and Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae)) was carried out under choice and no-choice conditions at 26 ^ 1 8C in both Petri dishes and cages. The aphidiine rejected L. erysimi and did not oviposit in this aphid species in any of the trials. In all tests, A. gossypii proved to be the aphid host preferred most frequently by L. testaceipes. This study contributes to the fundamental knowledge on the oviposition behaviour of L. testaceipes and provides information for use in the development of sustainable aphid pest management strategies in Benin.

Mud Wasp, Sceliphron madraspatanum (Fabricius) (Hymenoptera: Sphecidae): A Threat or Nature's Regulation of Spider Fauna in the Vegetable Agroecosystem?

The biology and behaviour of mud wasp, Sceliphron madraspatanum (Fabricius) and its possible role in insect pest management were studied under vegetable agroecosystem. The gravid female lays a single egg (2.75±0.33 mm in length) in a mud chamber that is provisioned almost exclusively with orb-weaver spiders, wolf spiders and jumping spiders available in the vegetable agroecosystem. Total numbers of spiders provisioned in each cell was negatively correlated with their mean body weight. However, the wasps avoided provisioning of lynx spider, the most predominant spider in this ecosystem, due to its short and reduced abdomen and also the presence of large, strong and erect setae over its body. In the agroecosystem, mud wasp was found to constitute the third trophic level in the food chain comprising of the vegetable crops–insect pests–spiders– S. madraspatanum and thereby their role could be detrimental for the pest management.

Aphids and their natural enemies in vegetable agroecosystems in Benin

This study was undertaken to provide new knowledge on biodiversity of aphids and their complex of natural enemies in vegetable agroecosystems in Benin. During a 2-year survey (2007/2008 to 2008/2009), aphid species, their host plants and natural enemies were identified from samples collected from 29 vegetable and 22 weed species at 30 vegetable production sites across Benin. A total of 82% of the vegetable species and 12% of the weed species were infested with aphids. Aphis gossypii Glover infested a wide range of the vegetables and occurred on 62% of the species, while Aphis craccivora Koch, Aphis spiraecola Patch, Lipaphis erysimi (Kalt.), Myzus persicae (Sulzer) and Toxoptera odinae (Van de Goot) were collected from a limited number of vegetables, each with a frequency occurrence ranging from 3 to 28%. The weeds Commelina benghalensis L. and Euphorbia hirta L. were common alternative weed hosts for aphids. Common natural enemies were the predators Cheilomenes propinqua (Mulsant), Cheilomenes sulphurea (Olivier) and Ischiodon aegyptius (Wiedemann), the obligate entomopathogen Neozygites sp., and the parasitoids Lysiphlebus testaceipes (Cresson) and Aphelinus ficusae Prinsloo & Neser. Lysiphlebus testaceipes was usually the only primary parasitoid on aphids across the sites and its common host was A.gossypii. From parasitized mummies, five species of hyperparasitoids were collected, the most abundant being Syrphophagus africanus (Gahan). These are the first records of L.testaceipes,S.africanus andA. spiraecola from West Africa. These findings provide baseline knowledge on the aphid fauna of Benin and contribute information for use in the development of sustainable vegetable pest management strategies in the country.

Insecticide dissipation from soil and plant surfaces in tropical horticulture of southern Benin, West Africa

In Sub-Saharan Africa, horticulture provides livelihood opportunities for millions of people, especially in urban and peri-urban areas. Although the vegetable agroecosystems are often characterized by intensive pesticide use, risks resulting therefrom are largely unknown under tropical horticultural conditions. The objective of this study therefore was to study the fate of pesticides in two representative horticultural soils (Acrisol and Arenosol) and plants (Solanum macrocarpon L.) after field application and thus to gain first insight on environmental persistence and dispersion of typical insecticides used in vegetable horticulture in Benin, West Africa. On plant surfaces, dissipation was rapid with half lives ranging from 2 to 87 h (alpha-endosulfan < beta-endosulfan < deltamethrin). Soil dissipation was considerably slower than dissipation from plant surfaces with half-lives ranging from 3 (diazinon) to 74 d (total endosulfan), but persistence of pesticides in soil was still reduced compared to temperate climates. Nevertheless, for deltamethrin and endosulfan, a tendency for mid-term accumulation in soil upon repeated applications was observed. The soil and plant surface concentrations of the metabolite endosulfan sulfate increased during the entire trial period, indicating that this compound is a potential long-term pollutant even in tropical environments.

Seasonal Abundance of Liriomyza sativae (Diptera: Agromyzidae) and its Parasitoids on Vegetables in Southern Vietnam

Native to the North America, Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) is widespread worldwide but mostly occurs in the temperature regions including South East Asian countries (Spencer, 1973; Murphy and LaSalle, 1999). Recently, L. sativae has been also recorded from China (Zhao and Kang, 2000) and Japan (Iwasaki et al., 2000). In Japan, L. sativae was found for the first time in 1999 in Kyoto and Yamaguchi Prefectures (Iwasaki et al., 2000). This species has quickly spread and become a serious pest of vegetable and ornamental crops in the fields and greenhouses. This rapid spread was mainly caused by transportation of plant materials for greenhouses and plastic tunnels. In northern areas beyond latitude 34 N in China, L. sativae can not overwinter in the outdoors (Zhao and Kang, 2000). In Vietnam, L. sativae is an economically important pest of a wide variety of vegetable and ornamental crops in the open fields (Andersen et al., 2002; Tran et al., 2005a, b). Recent outbreaks of the leafminer were treated by a wide range of conventional insecticides, but control was unsatisfactory (Johansen et al., 2003; Tran and Takagi, 2005). Frequent applications of these broad spectrum insecticides can adversely affect parasitoid abundance in the vegetable agro–ecosystems (Saito et al., 1996; Johansen et al., 2003), can promote the development of pesticide resistance within fly populations (Keil et al., 1985, Johansen et al., 2003; Hofsvang et al., 2005) and frequently lead to an increase in leafminer density (Oatman and Kennedy, 1976; Murphy and LaSalle, 1999). Agromyzid leafminers are known to have rich natural enemy communities. Eighteen species of hymenopteran parasitoids have been recovered from Liriomyza leafminers in central and southern Vietnam. Among them, Neochrysocharis beasleyi Fisher & LaSalle, Neochrysocharis okazakii Kamijo, Neochrysocharis formosa (Westwood) and Asecodes delucchii (Boucek) (Hymenoptera: Eulophidae) are numerically dominant species (Tran et al., 2006). They have played a very important role in leafminer suppression in natural ecosystems and cultivated areas with reduced insecticide use (Johnson et al., 1980; Murphy and LaSalle, 1999). The objectives of this study were to survey damage caused by L. sativae in two important vegetable–growing areas of the Ho Chi Minh City, southern Vietnam, and to monitor the seasonal abundance of the leafminer and its parasitoids. In this paper, the seasonal occurrence of L. sativae in Vietnam and Japan was also discussed. Seasonal Abundance of Liriomyza sativae (Diptera: Agromyzidae) and its Parasitoids on Vegetables in Southern Vietnam

An Assessment of Management Practices to Control Nutrient and Pesticide Levels in Vegetable Production Areas in the Rattaphum Catchment, Thailand

The over-use of agrochemicals may have adverse effects on soils along with surface and groundwater. An assessment of alternative management practices to reduce the application of agrochemicals and minimise the pollution of water resources was carried out in the vegetable agro-ecosystem in the Rattaphum Catchment. This paper details the factors that govern the volume of agrochemicals used on high intensity crops in this area, covering the choice of crop and cropping patterns, level of pest and weed infestation and the socio-economic status of farmers such as capital, size of holding and labour availability. Alternative management practices tested included (i) a reduction in the use of pesticides and chemical fertilisers; (ii) the use of bio-insecticides and bio-fertilisers; and (iii) the development of buffer zones near streams to reduce nutrient leaching into surface water systems.

Movement and persistence of methamidophos in vegetable agroecosystem.

Movement and persistence of methamidophos in vegetable agroecosystem.

Major species of the dung beetles (Superfamily: Scarabaeoidea) in three ecological systems in western Saudi Arabia

Members of the dung beetles superfamily Scarabaeiodea (families: Scarabaeidae and Aphodiidae) represent a major part of the ground‐dwelling fauna in a natural (fallow) and two agroecosystems in Western Saudi Arabia. The most abundant species include Pentodon algerinum Herbst and Aphodius assectora Balth. during the main activity period October‐May. Statistical analysis showed that there were no significant differences in the population density of both species between the three ecosystems under investigation. A pronounced peak of P. algerinum observed during November in the vegetable agroecosystem whereas a sharp peak observed during March in the natural (fallow) ecosystem. A. assectora was the dominant species with a sharp peak during February‐April in the vegetable agroecosystem which might be attributed to the abundance of decaying organic matter that resulted from crop harvesting. P. algerinum is active during early and late seasons October‐December and February‐April in the vegetable agroecosystem and natural (fallow) ecosystem respectively, whereas A. assectora is active during late season, February‐April in the vegetable agroecosystem. Low population numbers of both species were recorded in the datepalm agroecosystem which might be attributed to the predatory pressure exerted by residents of both Avian and vertebrate predators having continued presence and feeding on a high protein diet of immature and adult stages of both beetles.

686 Using an Agroecosystem Approach in Systems Research

Because cropping systems must fit into the environmental, social, cultural and economic reality of the farming community, it is essential that practitioners are included in designing experimental techniques and evaluating application for their farms. Iowa State Univ. conducted a series of Focus Groups with growers and agribusiness professionals to assist in the design of vegetable cropping systems research trials. Trials were established to investigate vegetable agroecosystem status and needs. An agroecosystem analysis seeks to identify indicators of sustainability in a system, including plant health, biological diversity, soil/water quality, and level of biological control of insects and diseases. From this work, a checklist of ecological parameters has been developed for use in cropping systems research. Examples from Iowa, California, and North Carolina will be presented as case studies, exploring multi-disciplinary approaches to cropping systems research.