scholarly journals Evaluation of Biorational Insecticides as Stand-alone Treatments for the Management of the Pigweed Flea Beetle, Disonycha glabrata (Coleoptera: Chrysomelidae), in Organic Production of Amaranthus spp.

2020 ◽  
Vol 9 (3) ◽  
pp. 58
Author(s):  
Roger V. Vorsah ◽  
Beatrice N. Dingha ◽  
Harmandeep Sharma ◽  
Louis E. Jackai
Keyword(s):  
Field Experiments ◽  
Insect Pest ◽  
Flea Beetle ◽  
Organic Production ◽  
Leaf Damage ◽  
Growing Seasons ◽  
Action Threshold ◽  
Treatment Action ◽  
Amaranthus Spp ◽  
Beetle Damage

The pigweed flea beetle, Disonycha glabrata, is the most damaging insect pest on Amaranthus spp. in the Piedmont zone of North Carolina (NC), United States. It is capable of causing severe yield loss on amaranth greens if uncontrolled. Field experiments were conducted over two growing seasons (Summer 2017 and 2018) in Greensboro, NC, to evaluate OMRI-approved biorational insecticides against D. glabrata in organic amaranth production. Insecticides evaluated included Azatin® O (azadiractin), Ecotec® (oils: rosemary, peppermint and geraniol), Entrust® (spinosad) and PyGanic® (pyrethrins) as stand-alone threshold-driven treatments applied at recommended label rates. Insecticide treatment action threshold (AT) was 2 (on a scale of 5) representing 20-40% leaf damage. The efficacy of the insecticides against D. glabrata population differed significantly within the amaranth varieties in comparison to their respective controls: treatments with Entrust® and PyGanic® on Green Callaloo and Red Leaf recorded 80% reduction in beetle population while Ecotec® gave only a 15% beetle reduction. The Azatin® O treatments recorded the highest D. glabrata population, sometimes greater than the control. Marketable fresh leaf yield from both Green Callaloo and Red Leaf amaranth was highest in the Entrust® and PyGanic® treatments. Hopi Red-Dye and Molten Fire amaranths showed some resistance to beetle damage; they are also intrinsically low yielding. These findings provide information that would make organic amaranth production possible with only limited and safe insecticide input using OMRI-approved insecticides in a threshold-driven manner, an important step towards the sustainable management of D. glabrata and amaranth production.

scholarly journals Organic Mulch Increases Insect Herbivory by the Flea Beetle Species, Disonycha glabrata, on Amaranthus spp.

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 162
Author(s):  
Roger V. Vorsah ◽  
Beatrice N. Dingha ◽  
Sudan Gyawaly ◽  
Sarah A. Fremah ◽  
Harmandeep Sharma ◽  
...  
Keyword(s):  
North Carolina ◽  
Pest Management ◽  
Insect Pests ◽  
Flea Beetle ◽  
Building Blocks ◽  
Organic Production ◽  
Leaf Damage ◽  
Yield Reduction ◽  
Vegetable Production ◽  
Amaranthus Spp

Amaranth (Amaranthus spp.) is an increasingly high-valued niche vegetable crop among small organic growers in North Carolina, due to its increasing demand among diverse immigrant groups. Production is however hampered by insect pests such as the flea beetle (FB), Disonycha glabrata (Coleoptera: Chrysomelidae), that cause significant yield reduction. Chemical insecticides are generally applied for pest control despite their known risks to health and the environment. Integrated pest management (IPM), which is a cost effective and environmentally friendly approach is still under-exploited in vegetable production by small growers. We studied IPM approaches, suitable for organic production of amaranth by screening nine amaranth varieties for resistance to the flea beetle (FB), D. glabrata, grown with, and without, mulch. D. glabrata population was 60% higher in plots with mulch compared to plots without. The amaranth varieties Molten fire and Green Callaloo recorded the lowest and the highest beetle population commensurate with low, and high leaf damage, respectively. Conversely, leaf yields in the mulched plots were 50% less than recorded in the zero-mulch counterpart, with Green Callaloo variety recording the lowest. These findings will serve as building blocks for a sustainable pest management plan that is appropriate for organic production of Amaranthus spp. in North Carolina.

scholarly journals Impact of Intercropping Sorghum and Okra on the Incidence of Flea Beetles of Okra Podagrica spp in Dalwa, Maiduguri Semi-Arid Zone of Nigeria

2014 ◽  
Vol 14 ◽  
pp. 51-58
Author(s):  
M.M. Degri ◽  
I.B. Richard
Keyword(s):  
Field Experiments ◽  
Insect Pests ◽  
Arid Zone ◽  
Flea Beetle ◽  
Fruit Weight ◽  
Fruit Yield ◽  
Leaf Damage ◽  
The Impact ◽  
Fruit Formation ◽  
Semi Arid

Field experiments were conducted at faculty of Agriculture teaching and research farm, university of Maiduguri in 2010 and 2011 rainy seasons. The aim was to investigate the impact of intercropping sorghum with okra on the incidence of flea beetle of okra (Podagrica spp) in the semi-Arid zone of Nigeria. The results showed that sole crop okra suffered flea beetle attack which affected its growth, fruit formation, fruit weights and fruit yield. Intercropping okra with sorghum significantly reduced the flea beetle populations, leaf damage caused by Podagrica spp (Coleoptera: Chrysomelidae). While increasing number of leaves for photosynthetic activities, plant height, fruit formation, fresh fruit weight and total fruit yield. The study concluded that okra intercropping at 1:1, 1:2 and 2:2 are the most efficient and productive intercrop systems in flea beetle management. Okra intercropping with cereal sorghum was found to be good for sustainable agriculture and organic farming in Nigeria due to its numerous advantages, particularly with respect to insect pests’ control.

scholarly journals Principal Insects Affecting Tobacco Plants in the Field

2018 ◽  
Vol 28 (3) ◽  
pp. 117-165
Author(s):  
Peter A. Edde
Keyword(s):  
Pest Management ◽  
Insect Pest ◽  
Flea Beetle ◽  
Tobacco Budworm ◽  
Monitoring Methods ◽  
Japanese Beetle ◽  
Black Cutworm ◽  
Action Threshold ◽  
The World ◽  
Scientific Name

SummaryTobacco, Nicotiana tabacum, is a high-value crop grown in many temperate and tropical countries of the world. Several insects attack tobacco throughout the season, from transplant production, growth in the field, during storage, and in the marketed product. This review focuses on economically important insects of the seedling tobacco or the growing crop in major tobacco-producing regions of the world. The species covered herein are tobacco aphid, black cutworm, tobacco budworm, tobacco hornworm, tobacco flea beetle, thrips, Japanese beetle, and tobacco wireworm. The occurrence and economic importance of these insects vary from region to region.For each insect discussed, the following information is provided: the scientific name and taxonomic position of the insect; its geographical distribution; the stage that causes the damage and plant hosts; a brief discussion on classification and description of the species; a summary of the biology and ecology; details regarding pest management, which include scouting-/monitoring methods, action threshold, cultural (non-chemical) methods, natural enemies, and chemical control. In addition, a concluding paragraph is presented on insect pest management for tobacco.

scholarly journals Host Range of Cotton Flea Beetle (Podagrica puncticollis) in a Hot Dry Tropical Environment of Ethiopia

2020 ◽  
Vol 19 (1) ◽  
pp. 21-31
Author(s):  
Agegnehu Eshetu ◽  
Mulatu B ◽  
Damte T ◽  
Wakgari M
Keyword(s):  
Host Range ◽  
Plant Species ◽  
Host Plants ◽  
Insect Pest ◽  
Flea Beetle ◽  
Tropical Environment ◽  
Leaf Damage ◽  
Growth Stages ◽  
Bidens Pilosa ◽  
North Western

Cotton flea beetle, Podagrica puncticollis is the most destructive insect pest of cotton in north-western part of Ethiopia. This study was conducted to identify and determine the host range of cotton flea beetle in Metema area. The field survey was undertaken from June 27, 2015 to January 9, 2016 in ten kebele administrations of the district. At least three fields were prospected after every 15 days, in each kebele for host plants as well as to determine population density and percent leaf damage by adult cotton flea beetle, at different growth stages of cotton plant. The composition of plant species with damaged symptom or infested by flea beetle was analysed using quantitative means and identified by comparing specimens with description of identification manuals. A total of 11 host plant species of cotton flea beetle were identified in the cotton growing areas of Metema throughout a season. Indigofera longibarbata (Fabaceae), Hibiscus articulatus, H. cannabinus, H. vitifolius, Abutilon figarianum, Sida alba and S. urens (Malvaceae), Bidens pilosa and B. setigera (Asteraceae), Corchorus olitorius and C. trilocularis (Tiliaceae) found to be common host plants of cotton flea beetle. Thus, among the host plants, H. vitifolius, H. cannabinus, H. articulatus, C. olitorius and C. trilocularis were the most suitable hosts for adult cotton flea beetle in respect of the number of adults per plant and percent foliage damage they sustained. These findings could aid in developing longterm management strategies for this important insect pest existing in a hot dry tropical environment of north-western Ethiopia.

scholarly journals Grape Cultivar Feeding Preference of Adult Japanese Beetles

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 196-199 ◽  
Author(s):  
Sanjun Gu ◽  
Kirk W. Pomper
Keyword(s):  
Field Experiments ◽  
Insect Pest ◽  
Feeding Preference ◽  
Leaf Damage ◽  
Leaf Position ◽  
Eastern United States ◽  
Japanese Beetle ◽  
Grape Cultivar ◽  
Chemical Inputs ◽  
Grape Cultivars

The Japanese beetle is a major insect pest of grapes in the eastern United States. An examination of Japanese beetle preference for currently grown grape cultivars would be useful to growers in developing pest control strategies with reduced chemical inputs. The objective of this study was to examine grape cultivar preference of Japanese beetles for commercially available grape cultivars in both cage choice and field experiments. Outdoor cage choice screening studies included 32 grape cultivars from various Vitis species and were conducted at the Kentucky State University Research Farm in Frankfort, KY. Feeding preference was determined by examining incidence of damage (percent of leaves damaged per vine) and leaf area loss, which was rated as 0 pt, 0%; 1 pt, 1% to 10%; 2 pt, 11% to 20%; 3 pt, 21% to 30%; 4 pt, 31% to 40%; 5 pt, 41% to 50%; 6 pt, 51% to 60%; and 7 pt, more than 60%, by leaf position from the first (shoot tip) to 10th leaves. Analysis of variance indicated that there were significant differences in Japanese beetle leaf damage for cultivar and leaf position main effects. Leaf damage by Japanese beetles varied by leaf position on the shoot, with the fourth through sixth leaves from the tip with the most severe damage. Generally, cultivars showing an incidence of damage greater than 70% were either European or French hybrid cultivars, and those with less than 70% incidence of damage were either American cultivars or American cultivars with a V. labrusca background. The grape cultivars Marquis, Reliance, Catawba, Concord Seedless, Concord, Edelweiss, and Einset showed promise as selections for growers interested in reduced chemical inputs for control of Japanese beetles.

Diverse sources of resistance to Spodoptera litura (F.) in groundnut

2019 ◽  
Vol 79 (01S) ◽  
Author(s):  
M. A. Saleem ◽  
G. K. Naidu ◽  
H. L. Nadaf ◽  
P. S. Tippannavar
Keyword(s):  
Recombinant Inbred ◽  
Spodoptera Litura ◽  
Hot Spot ◽  
Recombinant Inbred Lines ◽  
Insect Pest ◽  
Inbred Lines ◽  
Leaf Damage ◽  
Botanical Variety ◽  
Resistant Genotypes ◽  
Botanical Varieties

Spodoptera litura an important insect pest of groundnut causes yield loss up to 71% in India. Though many effective chemicals are available to control Spodoptera, host plant resistance is the most desirable, economic and eco-friendly strategy. In the present study, groundnut mini core (184), recombinant inbred lines (318) and elite genotypes (44) were studied for their reaction to Spodoptera litura under hot spot location at Dharwad. Heritable component of variation existed for resistance to Spodoptera in groundnut mini core, recombinant inbred lines and elite genotypes indicating scope for selection of Spodoptera resistant genotypes. Only 29 (15%) genotypes belonging to hypogaea, fastigiata and hirsuta botanical varieties under mini core set, 15 transgressive segregants belonging to fastigiata botanical variety among 318 recombinant inbred lines and three genotypes belonging to hypogaea and fastigiata botanical varieties under elite genotypes showed resistance to Spodoptera litura with less than 10% leaf damage. Negative correlation existed between resistance to Spodoptera and days to 50 per cent flowering indicating late maturing nature of resistant genotypes. Eight resistant genotypes (ICG 862, ICG 928, ICG 76, ICG 2777, ICG 5016, ICG 12276, ICG 4412 and ICG 9905) under hypogaea botanical variety also had significantly higher pod yield. These diverse genotypes could serve as potential donors for incorporation of Spodoptera resistance in groundnut.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Comparative Experimental Effects of Intercropping and Cypermethrin on Insect Pest Infestation and Yield of Maize, Cowpea and Okra in Two Cameroonian Agro-Ecological Zones

2021 ◽  
Vol 3 (2) ◽  
pp. 383-393
Author(s):  
Patient Farsia Djidjonri ◽  
Nukenine Elias Nchiwan ◽  
Hartmut Koehler
Keyword(s):  
Field Experiments ◽  
Insect Pests ◽  
Cropping Systems ◽  
Insect Pest ◽  
Maize Yield ◽  
Ecological Zones ◽  
Pest Infestation ◽  
Final Yield ◽  
Cropping Seasons ◽  
Agro Ecological Zones

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.

scholarly journals Late Leaf Spot Severity and Yield of New Peanut Breeding Lines and Cultivars Grown Without Fungicides

Plant Disease ◽  
2017 ◽  
Vol 101 (11) ◽  
pp. 1843-1850 ◽  
Author(s):  
Brian S. Jordan ◽  
Albert K. Culbreath ◽  
Timothy B. Brenneman ◽  
Robert C. Kemerait ◽  
William D. Branch
Keyword(s):  
Leaf Spot ◽  
Vegetation Index ◽  
Field Experiments ◽  
Organic Production ◽  
Canopy Reflectance ◽  
Cercospora Arachidicola ◽  
Early Season ◽  
Late Leaf Spot ◽  
Breeding Lines ◽  
Width Measurements

Peanut (Arachis hypogaea) cultivars with resistance or tolerance to Cercospora arachidicola and/or Cercosporidium personatum, the causes of early and late leaf spot, respectively, are needed for organic production in the southeastern U.S. To determine the potential of new breeding lines for use in such production systems, field experiments were conducted in Tifton, GA, in 2014 and 2015 in which nine breeding lines and two cultivars, Georgia-06G and Georgia-12Y, were grown without foliar fungicide applications. In one set of trials, cultivar Georgia-12Y and most of the breeding lines evaluated had early season vigor ratings, early-season canopy width measurements, final plant populations, and pod yield that were greater than those of standard cultivar Georgia-06G. In those trials, final late leaf spot Florida scale ratings were lower and canopy reflectance measured as the normalized difference vegetation index (NDVI), was higher all the breeding lines than those of Georgia-06G. In another set of trials, two of those same breeding lines had final late leaf spot ratings similar to those of Georgia-12Y in 2014, whereas in 2015, six of those breeding lines had final leaf spot ratings that were lower than those of Georgia-12Y. Yields were similar for Georgia-12Y and all the breeding lines in the Gibbs Farm trials. Across years and breeding lines at the Lang Farm, the relationship between visual estimates of defoliation and NDVI was described by a two sector piecewise regression with NDVI decreasing more rapidly with increasing defoliation above approximately 89%. The utility of NDVI for spot comparisons among breeding lines appears to be limited to situations where there are differences in defoliation. Georgia-12Y and multiple breeding lines evaluated show potential for use in situations such as organic production where acceptable fungicides available for seed treatment and leaf spot control are limited.

Do applications of sulfur or sulfate influence infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola?

2002 ◽  
Vol 82 (3) ◽  
pp. 599-610 ◽  
Author(s):  
L. M. Dosdall ◽  
R. -C. Yang ◽  
P. M. Conway
Keyword(s):  
Brassica Rapa ◽  
Field Experiments ◽  
Elemental Sulfur ◽  
Insect Pest ◽  
Soil Surface ◽  
Application Rate ◽  
Delia Radicum ◽  
Application Methods ◽  
Root Maggot ◽  
Sulfur Nutrition

While the importance of sulfur nutrition for the development of healthy stands of canola is well documented, the role of sulfur in the management of insect pest infestations has not previously been investigated in this crop. Field experiments were conducted at three sites in central Alberta in 1997 and 1998 to determine the influence of sulfur and sulfate applications on infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola (Brassica rapa L.). Different formulations (granules, powder, prills, and sprays), application methods (either drilled in with the seed or top-dressed on the soil surface), and application rates were evaluated. To assess the degree of root maggot infestation, oviposition throughout the season and damage to taproots at the end of the season were monitored. Sulfur contents were analyzed from leaf samples collected mid-season and seed yields were measured from all treatment plots. Root maggot responses to the different sulfur treatments and application methods varied among years and sites, indicating that environmental factors have great importance in determining infestation levels by these pests, and the oxidation rate of elemental sulfur in soil. Sulfur formulation and application rate had significant effects on root maggot egg deposition and root damage for some sites and years, but even at high rates of application (112 kg ha-1) reductions in infestation levels were not substantial relative to the controls. While sulfur additions alone will not greatly reduce root maggot infestation levels in canola, growers should employ adequate sulfur nutrition for optimum crop health to enable plants to better compensate for damage by these pests. Key words: Brassica rapa, Delia radicum, Delia floralis, elemental sulfur, sulfate, canola

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