Pod Damage Research Articles

Research progress and mitigation strategies for pod shattering resistance in rapeseed.

Mature rapeseed pods typically shatter when harvested, resulting in approximately 8-12% yield loss. Adverse weather conditions and mechanized harvesting can diminish pod yield by up to 50%, primarily owing to delays in harvesting and mechanical collisions. The pod shatter resistance index (PSRI) assesses pod damage. Recent research focused on comparing pod shatter resistance among varieties, evaluating methods, and studying gene knockout mechanisms. However, there remains a pressing need to broaden the scope of research. In particular, it is essential to recognize that pod shatter, a complex trait, influenced by genetics, environment, agronomic practices, and harvest techniques. Future studies should integrate these factors to develop comprehensive strategies to mitigate pod shatter, enhancing rapeseed yields and agricultural mechanization. This review explores factors affecting pod shatter resistance and strategies to improve it. Scoping literature review that adhered to the methodological framework for systematic reviews was performed using search engines such as Google Scholar, Web of Science, and the Chinese National Knowledge Infrastructure. This review aimed to identify pertinent articles, which were subsequently subjected to thorough screening and evaluation. The protocol for this literature review involved the following key steps: definition of research questions, development of a search strategy, development of data extraction strategy, synthesis of the extracted data, and organization and analysis of the extracted data. The review presents strategies for enhancing rapeseed yield during mechanized harvesting, focusing on four key areas: (i) selecting and breeding shatter-resistant varieties using DNA markers to establish a robust germplasm resource; (ii) optimizing cultivation technologies and agronomic measures to elicit favorable interactions between compact plant-type genotypes and the environment, thereby facilitating nutrient-related regulatory mechanisms of rapeseed pods to improve pod dry weight and resistance; (iii) innovating combine header design and structure to better suit rapeseed harvesting; and (iv) providing training for operators to enhance their harvesting skills. These comprehensive measures aim to minimize yield loss, increase production efficiency. To effectively reduce yield loss during mechanized harvesting of rapeseed, it is crucial to enhance resistance to pod shattering by addressing both internal physiological factors and external environmental conditions. This requires a holistic approach that includes genetic improvements, optimization of ecological conditions, careful cultivation management, and precise harvesting timing, along with ongoing research into traits related to machine harvesting to boost production efficiency and sustainability.

Damage Intensity of Pod Borer Attack on Seven Soybean Cultivars on Mahogany and Pine Agroforestry

Damage Intensity of Pod Borer Attack on Seven Soybean Cultivars on Mahogany and Pine Agroforestry

Assessment of Plants Alkaloids Isolated from Calotropis Procera for Managing Pod Sucking Bug, Clavigralla tomentosicollis Stal (Hemiptera: Coreidae) Infestation on Cowpea

Crude plant extracts used to control insect pests are less specific and the active compounds may have antagonistic effects. The trials were thus conducted to assess the effectiveness of alkaloids from Calotropis procera in controlling the pod sucking bug Clavigralla tomentosicollis on cowpea. Three cowpea varieties, Ife brown, IT07K-318-33, and IT07K-292-10, were grown in beds assigned to four treatment groups: 500µg/ml, 250µg/ml, 125µg/ml, and 0µg/ml of the extracts as a control. Each treatment was replicated three times in a randomized complete block design. The findings revealed a significant decrease (p<0.05) in the population of C. tomentosicollis in the treated plots compared to the control. The highest level of protection was observed in plots sprayed with 500µg/ml and 250µg/ml, with no significant difference (p>0.05) between treatment and spray regimes (1-week after spray (1-WAS) and 2-weeks after spray (2-WAS). The average percentage of pod damage was significantly lower at higher treatment concentrations (500µg/ml and 250µg/ml) compared to lower concentrations and the control. There was no significant difference in pod damage among the three cowpea varieties. The relative adult mortality of C. tomentosicollis followed a similar pattern, with higher concentrations (500µg/ml and 250µg/ml) resulting in a significant decrease in ITOK-292-10 compared to other varieties. In the ITOK7-318-33 variety, there was no significant difference in mortality rates between treatments (500µg/ml, 250µg/ml, and 125µg/ml) and spray regimes. This implied that treatment of cowpea ITOK-292-10 with the higher concentration of the Alkaloid (2-piperidinone, N-(4-bromo-n-butyl) would yield an optimum level control of the notorious bug.

Preliminary Evaluation of Onion Bulb and Tobacco Leaf Extracts for Insect Control and Yield of Cowpea in the Southern Guinea Savanna of Nigeria

The study evaluated the effects of onion (Allium cepa) bulb and tobacco (Nicotiana tabacum) leaf extract on the insect pests and yield components of cowpea. The extracts were tested on number of the flower thrips, Megalurothrips sjostedti Trybom, the pod-sucking bug, Clavigralla tomentosicollis Stal, the pod borer, Maruca vitrata (F.) and cowpea aphid, Aphis craccivora Koch. Also evaluated were the dry seed weight, 100-seed weight, pod length, number of pods per plant, number of seeds per pod, pod load, pod damage and pod evaluation index. Field experiment was conducted in the Faculty of Agriculture, University of Ilorin, Ilorin, Nigeria. Plots were laid out in a randomized complete block design with three replications. Treatments included 10% (w/v) of each of onion bulb and tobacco leaf extracts, synthetic insecticide (Cypermethrin 1 L/ha) and untreated control. Results revealed that cowpea treated with the plant extracts had significantly (p<0.05) lower insect pest population than plants in untreated plots which suffered greater insect pest attack. However, plots treated with Cypermethrin produced significantly higher number of seeds per pod than other treatments. Nevertheless, tobacco leaf extract produced significantly (p<0.05) heavier 100-seed weight than other treatments including the control. It could be concluded that the plant extracts had potential to replace the synthetic insecticide for control of insect pests of cowpea, thus ensuring environmental safety.

The Mathematical Model of Relationship Between Population of Pod Sucking Bug Nezara viridula L. and Soybean Pod Damage

The aims of this research are: (1) to predict the damage of soybean pod through the mathematical model of relationship between population density of N. viridula and pod damage, (2) to predict the soybean yield through the mathematical model of relationship between population density of N. viridula and pod damage where made by modification of Reynolds Transport Theorem. This research was used Completely Randomized Design with nine treatments and each was replicated three times. The treatment were : P0 = control, P1 = 1 nymph, P2 = 2 nymphs, P3 = 3 nymphs, P4 = 4 nymphs, P5 = 1 adult, P6 = 2 adults, P7 = 3 adults, and P8 = 4 adults. The population density of pod sucking bug was the independent variable, while dependent variables were : rate of pod damage, and dry pod weigh. Analysis of mathematical modeling was made by approaching of Continuum Theory and Reynolds Transport Theorem. The results showed that : (1) Relationship between population of N. viridula and pod damages in the form of mathematical model which is used to predict the soybean pod damage has error 0,02 – 0,10%, and (2) Mathematical model where made by modification of Reynolds Transport Theorem which is used to predict the soybean yield has error 0,01 – 1,00%.

Screening of Soybean Advanced Breeding Lines for Resistance Against the Southern Green Stink Bug Nezara viridula L (Hemiptera: Pentatomidae) under Free-Choice and No-Choice Tests

Background: The southern green stink bug (SGSB), Nezara viridula, is a potentially harmful pod sucker insect found in soybean. Objective: The objective of this study was to evaluate the resistance level of several soybean advanced breeding lines against the southern green stink bug N. viridula under the free-choice and no-choice tests. Methods: The research materials were 14 advanced breeding lines and four check cultivars. The experiment was conducted in Malang, East Java, Indonesia, during the dry season I and II 2022. The resistance evaluation of the soybean genotypes against the N. viridula was under the Free-Choice test (FC) and the No-Choice test (NC). The newly emerged adults N. viridula were infested when plants reached the R5 stage. The data were observed for damage intensity, yield and yield components. Results: The intensity of pod damage in the FC ranged from 20.09 to 46.40%, meanwhile, in the NC was 25.63 to 67.63%. This shows that the NC condition provides more selection pressure than the FC. Each genotype exhibited different resistance reactions in the FC and NC. The pod damage intensity had a significant negative correlation with seed yield both in the FC and NC. Conclusion: The No-Choice test (NC) provided a higher selection pressure for resistance to SGSB than the Free-Choice test (NC). The use of SGSB-resistant cultivars will prevent soybean seed yield losses. A new finding in this study, two soybean genotypes Anj/Rjbs-305 and Anj/Rjbs-306 were resistant to SGSB. Both genotypes exhibit good agronomic performance (high yield and large seed size), thus can be proposed as new soybean varieties to be developed in the country.

Synergism of Plant Oils with Different Insecticides against Pod Borer, Helicoverpa armigera (Hubner) Hardwick Infesting Chickpea

Background: Gram pod borer, Helicoverpa armigera (Hubner) Hardwick has developed high level of resistance against so many insecticides due to some operational and biotic factors. The resistance can be managed by many ways among which adding of plant materials in insecticidal solution, which is having a synergistic effect, is one of the better ways to overcome this problem. Methods: In aim to break the resistance of insecticides towards this pest, an experiment was carried out to know the synergistic effect of different plant oils along with different insecticides against pod borer infesting chickpea at Junagadh Agricultural University, Junagadh (Gujarat) during two consecutive years i.e., 2017-18 and 2018-19. The experiment was laid in randomize block design having nine treatments (two oils and three insecticides) along with control. Result: The results revealed that the minimum (10.98 %) pod damage was observed in the treatment of chlorantraniliprole 18.5 SC 0.006 % + neem oil 0.5% which was found at par with flubendiamide 48 SC 0.015% + neem oil 0.5% (12.04 %). As far as the yield and economic is concern, highest (2634 kg/ha) yield and net realization (57,008 Rs /ha) was recorded in the treatment of chlorantraniliprole 18.5 SC 0.006 % + neem oil 0.5% followed by flubendiamide 48 SC 0.015% + neem oil 0.5% (2432 kg/ha and 45,934 Rs /ha ). The highest (1:10.33) ICBR was obtained in the treatment of chlorantraniliprole 18.5 SC 0.006 % + neem oil 0.5% followed by chlorantraniliprole 18.5 SC 0.006 % (1:9.36) and flubendiamide 48 SC 0.015% + neem oil 0.5% (1:7.13).

Assessing Pigeonpea Genotypes for Resistance against Maruca vitrata Fabricius and its Sustainable Management through Biorationals

Background: The spotted pod borer (SPB), Maruca vitrata Fabricius is a key insect pest of major legume crop i.e. pigeonpea, Cajanus cajan in India and semi-arid tropics. Identifying a SPB resistant genotype will help in sustainable management of SPB and in attaining nutritional security. The SPB has developed insecticide resistance to most of the chemical insecticide like Organophosphorous group of insecticides and also it is expanding its geographic limits. These factors are the driving forces for identifying tolerant genotypes for its sustainable management along with a suitable biorational. Methods: Forty seven pigeonpea genotypes were screened during kharif 2015 to 2017 at ICAR-IIPR, Kanpur based on percent pod damage and Pest Resistance Susceptibility Rating (PRSR) under insecticide free condition. The 4 biorationals were tested against SPB in ICPL 87 along with untreated control in Randomised Block Design. Further the SPB molecular identity was confirmed by phylogenetic analysis of partial Cox 1 gene amplified from M. vitrata adult. Results: Two indeterminate genotypes (Pusa2001 and Pusa33) as SPB resistant based on lowest mean pest resistance susceptibility rating (PRSR 1.7) The next best genotypes were a determinate (AL-15) and indeterminate genotype (LRG-30) with a PRSR of 2.0. The highest PRSR (6.0) was recorded from the ICPL 87, a susceptible check in the present experiment. Spinosad 45SC has recorded significantly lowest mean pod damage (6.67%) and highest mean yield (4.36kg/35m2) compared to 4 other treatments in the field efficacy trial. The phylogenetic analysis of Cox 1 gene from Kanpur population (KY559101) with 19 other M. vitrata populations in India revealed that it is more similar to Raichur population (KT070892) and it confirms M. vitrata has same ancestral homology in India.

Mpact of Chickpea Varieties and Sowing Dates on Pod Borer Helicoverpa armigera (Hubner)

Background: Global warming and climate change will have a major bearing on population and incidence of insect-pests and their associated yield and quality losses in different crops. In chickpea, a number of insect-pests are observed which mainly limit its production and productivity. Among these, gram pod borer, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a major and prominent pest in different chickpea growing areas of the country. The increased demand of residue free crop produce will definitely motivate farmers to select alternative management strategies instead of insecticides for management of insect-pests. Therefore, the current study aimed to determine the effect of different chickpea varieties at different dates of sowing on the population and incidence of gram pod borer. Methods: The present study was conducted at Regional Research Station, PAU-Gurdaspur during Rabi seasons of 2019-20 and 2020-21 to determine the effect of chickpea varieties (PBG 7 and PBG 8) and different sowing dates viz. 25thOctober, 05, 15 and 25thNovember on the larval population and per cent pod borer infestation of Helicoverpa armigera. Result: It was concluded that both the tested chickpea varieties had non-significant effect on population of pod borer, pod damage and gram yield. However, the pod borer’s larval population and pod infestation decreased across sowing dates from last week of October to last week of November. The mean larval population and incidence of H. armigera decreased with a delay in time of sowing i.e. 7.88 and 5.29 larvae/3 rows and 62.96 and 42.27% pod damage in the 25thOctober and 25thNovember sown crop, respectively. The maximum grain yield (17.45 q/ha) was obtained from 15th November sown crop.

EVALUATION OF DIFFERENT IPM MODULES FOR THE MANAGEMENT OF CHICKPEA POD BORER, HELICOVERPA ARMIGERA (HUBNER)

A field experiment was conducted at the Agricultural Research farm of Rani Lakshmi Bai Central Agricultural University, Jhansi during the Rabi season 2021-22 to find out the efficacy of different IPM modules on the larval population of Helicoverpa armigera (Hubner) in chickpea. Among the different tested management modules, module-2 comprising of Spinosad 45% SC (75 g a.i./ha) + Datura leaf extract 25% was found to be most effective in minimizing the larval population (0.69 larvae/ 5 plants) along with that the lowest percent pod damage (6.91%), the highest yield (1.57 t/ha) and the highest net profit were also obtained. However, the highest incremental benefit-cost ratio was recorded in module-1 [NSKE 5% + Marigold (Transplanting 15 days after sowing of chickpea in 3:1)] (6.32: 1) due to less pesticide application and more return obtained from Marigold.

Effect of soybean variety and pest management on the sustainable production

Pests are one of the limiting factors in increasing soybean production. Pest control carried out by farmers using pesticides is feared to threaten the sustainability of soybean production in Indonesia. This study aimed to identify the effect of different pest management systems and various soybean varieties on pest population dynamics, abundance and diversity of natural enemies, plant damage, and soybean production. A split plot design with three replications was applied, where the main plot was pest management systems i.e. (1) control (which received neither chemicals nor integrated pest management), (2) chemical control, and (3) integrated pest management, and the sub-plot was soybean varieties i.e. (1) Anjasmoro, (2) Demas 1, and (3) Dering 1. Results indicated that variety affects pest diversity and abundance, however, it affected leaf damage, pod damage, and production. The pest management systems influenced the diversity and abundance of pests and natural enemies, plant damage, and production. Interaction between variety and pest management system affected plant damage. We conclude that the use of resistant varieties combined with integrated pest management could reduce plant damage, maintain the natural enemy population, and optimize soybean production.

Evaluation of cowpea genotypes for resistance to the legume pod borer, Maruca Vitrata (Fabricius) (Lepidoptera: Pyralidae)

16 cowpea varieties were screened for resistance to the legume pod borer, Maruca vitrata F. under natural infestation in the field. Plants were planted in a randomized complete block design in three replicates; each plot consisted of four rows, 3m long. Spacing was 1.5m between plots and 0.75m between rows. Intra- row spacing was 0.2m.Two weeks prior to planting experimental materials, a susceptible cultivar was planted perpendicular to every range of rows within a plot to serve as a reservoir of the test insect, M.vitrata. Plants were sprayed with Monocrotophos at 200g a.i /ha once at the vegetative stage and at the onset of flower bud initiation and later during podding to control other pests apart from Maruca. Larval density, flower damage, pod damage, seed damage, pod load (a measure of the degree of successful pod production) and Index of pod evaluation (Ipe), calculated as [PL X (9-PD)], (a measure of the varietal performance of the cowpea genotypes) were used to assess resistance in cowpea varieties. Significant variations were observed in the level of resistance among the cowpea genotypes in the field. The findings show that Tvu 4578 is resistant while Tvu 1544, IT97K-499-35, IT93K452-1 and IT90K-76 show promising level of resistance. The probable factor contributing to resistance may be non- preference or host plant resistant factors.

Bio-Efficacy of Spinetoram 6% W/V (5.66% W/W) + Methoxyfenozide 30% W/V (28.3% W/W) SC against Pod Borers Infesting Greengram [Vigna radiata (L.) Wilczek

Background: Spotted pod borer, Maruca vitrata (F.) and blue butterfly, Lampides boeticus (L.) are important lepidopteran borers infesting greengram [Vigna radiata (L.) Wilczek] throughout India. Therefore, novel insecticide mixture in comparison with other standard synthetic insecticides has been tested for its bio-efficacy against these two borers in greengram. Methods: A field experiment was conducted at Vagurani, Usilampatti Block, Madurai district, Tamil Nadu during June to August, 2020 in randomized block design (RBD) with eight treatments and three replications. The experimental field was monitored for the population of pests and natural enemies (No./ 10 plants), per cent pod damage, total grain yield and phyto-toxic symptoms. From the data recorded, per cent reduction in population over control was calculated. The per cent pod damage was calculated by randomly picking 100 pods from each plot of each replication. The grain yield from each plot was recorded after each picking and converted into kg/ ha. Result: Two sprays of spinetoram 6% w/v + methoxyfenozide 30% w/v SC @ 144 g a.i/ha and flubendiamide 34.35 SC @ 48 g a.i/ha from 45 DAS at 15 days interval proved to be most effective and superior in reducing the lepidopteran pod borers like M. vitrata and L. boeticus and no lethal effect was recorded towards the coccinellid predators, Menochilus sexmaculatus, C. transversalis and spiders. This combination did not cause any phytotoxic symptoms like leaf injury, wilting, vein clearing, necrosis, epinasty and hyponasty at any day after treatment on stems, leaves, flowers and pods of greengram.

Bio-efficacy of newer insecticides against gram pod borer Helicoverpa armigera (Hubner) on chickpea (Cicer arietinum L.)

Six insecticides namely Emamectin benzoat 5% SG, Spinetoram 11.7% SC, Spinosad 45.0% SC, Flubendiamide 48 % SC, Chlorantraniliprole 18.5% SC, Novaluron 10% EC were evaluated against Gram Pod Borer (Helicoverpa armigera Hubner) larvae. The Gram Pod Borer (GPB) larval population was counted on five randomly selected plants, 24 hrs. before spray and at 3, 7 and 10 days after spray. The two-year experiment was conducted during Rabi 2018-19 and 2019-20 at the Rehti Farm of school of agriculture, Mhow, experimental field of Department of Entomology, BRAUSS, (MP). All the Chemical insecticides significantly reduced the GPB larval population. The Pooled GPB population varied from 2.23 to 2.57 larvae/ plant during Rabi season at one day prior to first spray. The population was significant lower with, Chlorantraniliprole 18.5% SC, followed by Spinetoram 11.7% SC, Spinosad 45.0% SC, Flubendiamide 48 % SC and Emamectin benzoat 5% SG these five insectiicdes are showing best management effects on the GPB larvae and pod damage .Novaluron 10% EC gave are least effective on larval population and pod damage. The highest chickpea grain yield (19.13q/ha) was obtained with Chlorantraniliprole 18.5% SC.

Induced defense responses in cultivated and wild chickpea genotypes against Helicoverpa armigera infestation.

Five desi (GL 12,021, GL 29,095, GL 29,078, H11 22 and CSJ 515) and three wild (GLW 22, GLW 58 and GLW 187) chickpea cultivars showed induced defense response against Helicoverpa armigera infestation as a result of enhanced activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, polyphenol oxidase, phenylalanine ammonia lyase, tyrosine ammonia lyase in leaves, pod walls and seeds. Catalase activity increased in leaves of GL 12,021, H11 22, GL 29,095, CSJ 515, GLW 22, and GL 29,078 after infestation compared to resistant check; catalase and peroxidase activities in GL 29,095 and GL 29,078; ascorbate peroxidase and glutathione reductase activities in leaves of GLW 58. The increased activity of superoxide dismutase in pod wall of H1122; catalase in pod wall of 29,078, GL 29,095 and GL 22; ascorbate peroxidase and glutathione reductase in pod wall of GLW 58; phenylalanine ammonia lyase and tyrosine ammonia lyase in pod wall of GLW 187, H11 22, GL 20,978, GLW 22 and GLW 58 after infestation as compared to resistant check might be responsible for mitigating infestation induced oxidative stress. MDA content decreased in leaves, pod wall and seeds of GLW 187 and GL 12,021 after infestation. Lower percent pod damage (9.58-12.44%) in GL 12,021, GLW 187, GL 29,095, H11 22, GL 29,078, GLW 22 and GLW 58 as compared to resistant (16.18%) and susceptible (21.50) checks might be attributed to differential induced defense mechanism in them. The identified desi and wild genotypes might be used in breeding program to develop cultivars with improved resistance to herbivore.

Screening of pea germplasms against insect pests

A field experiment was conducted to screen fifteen germplasms of peas against different insect pests at Pulses Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat during rabi 2019-20 and 2020-21. The germplasm HFP 1502 recorded significantly minimum aphid (Aphis craccivora Koch) (3.78 aphids/10 cm shoot) whereas, the germplasm Pant P 476 recorded significantly lowest leafhopper (Empoasca kerri Pruthi) population (1.96 leafhoppers/3 leaves). Out of fifteen field pea germplasm significantly lowest whitefly (Bemisia tabaci Gennadius) population (0.94 whitefly/3 leaves) was noticed on the IPFD 10-12. The Helicoverpa armigera Hubner larval population indicated a significant minimum (0.39 larva/plant) on germplasm Pant P 418 and also recorded significantly lower (3.24%) pod damage. The significantly highest seed yield (937 kg/ha) was recorded on Pant P 476 followed by genotypes IPFD 10-12, Prakash, and IPF 18-14.

Screening of Cowpea Genotypes for Field Resistance to the Spotted Pod Borer (Maruca vitrata)

Background: Cowpea [Vigna unguiculata (L.) Walp.] is an important legume crop known for its nutritional value. However, the cultivation of this crop is greatly hampered by a destructive pest, a spotted pod borer (Maruca vitrata Fab.). Keeping the caustic nature of the pest in view, the present study was undertaken. Methods: Field evaluation of thirty cowpea genotypes was carried out by raising cowpea plants in an open field. Observations on the M. vitrata incidence were recorded at three days’ intervals starting from the development of the first buds to the end of flowering. Based on the level of infestation of buds, flowers and pods, the cowpea genotypes were categorised into four groups viz., resistant, moderately resistant, susceptible and highly susceptible. Results: Results of the study revealed a significant variation between the genotypes in terms of total damage (0.21 to 48.46%). Genotype IC 2918 recorded remarkably low damaged (0.12%) and was on par with Palakkadan thandan payar, Hridya, EC 300039, EC 101216, EC 98668, IC 39945, IC 52110, IC 39922 and IC 39916. The genotype Bhagyalaxmi recorded the highest damage (48.46%) followed by the variety Lola (30.04%). Flower buds were more susceptible to M. vitrata and suffered severe damage as compared to flowers and pods. Conversely, genotypes EC 98668 and IC 39922 were free from bud damage. Genotypes EC 300039, EC 98668, IC 52110, IC 39945, IC 2918 and IC 39922 recorded no flower damage and Palakkadan thandan payar, IC 39945, IC 2918 and IC 39947 recorded no pod damage.

Chemical Management of Spilosoma obliqua Walker in Greengram

Background: Greengram the most important pulse crops in India suffers a lot due to infestation of many lepidopteran caterpillars mainly at its reproductive stage. Spilosoma obliqua Walk. Arctiidae, Lepidoptera commonly called Bihar hairy caterpillar (BHC) is categorized as the most devastating. Methods: Field efficacy of nine new generation popular insecticides were tested in coastal saline zone of West Bengal against BHC in greengram (IPM 2-3) during 2021-2022. Leaf dip bioassay study of those selected insecticides were also conducted to compute the LC50 value against the field collected as well as laboratory reared F2 generation 3rd instar larvae of BHC. Result: All the test insecticides showed lethal effect towards BHC but the magnitude of protection over control was significantly higher in spinosad (70.92%) followed by flubendiamide (70.35%). Pyriproxifen+fenpropathrin (29.92%) was proved to be the least effective treatment followed by pyriproxyfen+bifenthrin (31.91%). As per LC50 value (ppm) flubendiamide showed the highest toxicity against BHC in respect of laboratory reared caterpillar and field collected caterpillar (4.49 and 6.71 respectively), while pyriproxifen+fenpropathrin the lowest (624 and 637 ppm). BHC was recorded as potent defoliator which was reflected in yield, while pod damage is not so pronounced.

Management Approach Against Pod Borer, Eucrysops Cnejus F. Attacking Yard Long Bean

Several management approaches were evaluated against pod borer attacking yard long bean during April - July, 2019 at Entomology Research Field, Bangladesh Agricultural Research Institute (BARI), Gazipur. The management package namely sanitation + spraying bio-pesticide Antario (Package 1), sanitation + spraying bio-pesticide Spinosad 45 SC (Package 3) and sanitation + alternate spraying of Antario and Spinosad 45SC (Package 4) showed almost equal effectiveness in reducing flower and pod damage by pod borer and higher yield. But the management package sanitation + spraying bio-pesticide Antario (Package 1) appeared best as it provided the highest marginal benefit cost ratio (MBCR) (10.09), which was followed by sanitation + alternate spraying of Antario and Spinosad 45SC (6.97) (Package 4), and sanitation + spraying biopesticide Spinosad 45 SC (5.29) (Package 3). The effectiveness of sanitation +Bt kurstaki) (Package 2) was poor in respect of yield (12.06 tha-1) and MBCR (3.44).
 Bangladesh J. Agril. Res. 45(3): 233-237, September 2020

The Chickpea Pod Borer, Helicoverpa armigera (Hübner): Yield Loss Estimation and Biorational Insecticide Assessment in Morocco

Helicoverpa armigera (Hübner) is considered one of the most destructive insect pests of chickpea crops in Morocco; however, the extent of the yield loss it causes in Morocco is unknown. This study assessed the yield losses and pod damage caused by the chickpea pod borer H. armigera on four improved Kabuli varieties with insecticide treatment at two different locations. The second part of this study investigated the contact and systemic toxicity of different biological and selective insecticides in the control of the larvae of H. armigera under controlled laboratory and field conditions. The results demonstrated that the yield losses due to H. armigera infestation were in the range of 14.3–31.2%. Chickpea pod borer infestation resulted in losses in the total seed weight for all the chickpea varieties, with the highest yield losses for Zahor (F84-145C) being 31.18% at Allal Tazi followed by Farihane (F84-79C) with 27.38% at the Marchouch station. Emamectin benzoate at 250 g/ha showed a high level of larvicidal and systemic activity, with 100% mortality 24 h after application. Indoxacarb at 25 mL/100 L water, recorded 100% and 92% larval mortality in larvicidal and systemic activity, 48 h after application, respectively. The bioinsecticide spinosad in 30 mL/100 L water resulted in 88% and 92% larval mortality in contact and systemic activity, 48 h after application, respectively. Under field conditions, the two insecticides emamectin benzoate and indoxacarb were found to be highly effective in reducing the H. armigera larval population and pod damage after two sprays. Both insecticide treatments significantly increased grain yields compared with the untreated plots, with 25.8% and 24.5%, respectively. These findings showed that two applications of the selective chemical insecticides emamectin benzoate or indoxacarb with a week interval starting from the pod setting could be incorporated into the management strategies for the control of H. armigera.