Effect of Larval Density of Helicoverpa armigera (Hubner) on Pod Damage and Yield of Chickpea

Background: Chickpea (Cicer arietinum L.) is cultivated in almost all parts of world covering more than 50 countries spread over Asia, Africa Europe, Australia, north America and South America countries and is the second most important food legumes crop after common bean (Phaseolus vulgaris L.). Chickpea has played a major role in realization of pulse Revolution in india making the country near self-sufficient in pluses. Gram is extensively grow in india. Due to its high nutritional value and its ability to fix atmospheric nitrogen, its more widely cultivated rabi pulse crop. The gram pod borer Helicoverpa armigera (Hubner) is most important pest of chickpea. Many pesticides were so far tested against this pest but due to over use of these pesticides resistance, residue and resurgence problems arises, beside destruction of natural enemies. Methods: To determination of per cent pod damage and yield of chickpea due to different larval density of H. armigera is an important tool to reduce the cost of cultivation by avoiding the unnecessary use of pesticides. Therefore, a pot experiment was conducted in arranged in a completed randomized design with four replications. The pots were placed under natural field conditions and take observation at Research farm, Rajasthan Agricultural Research Institute, Durgapura, Jaipur during 2015-16 and 2016-17. Result: The results revealed that least per cent pod damage (29.05, 24.78%) was recorded when the larval population was one per plant, while the maximum pod damage (64.55 and 67.76%) was recorded during 2015-16 and 2016-17, respectively. The simple liner correlation analysis indicated that there was a significant positive correlation (r= 0.989 and 0.999) between the larval density and per cent pod damage. Further, a significant correlation was noticed between larval density and number of healthy pods per plant, reduction in yield, yield per plant, total number of pod and damaged pods were -0.964, -0.976; 0.98, 0.986; -0.98, -0.986; 0.117, 0.126 and; 0.985 and 0.992, respectively during 2015-16 and 2016-17.

Morphological and biochemical traits in chickpea resistance against Helicoverpa armigera Hubner (Lepidoptera: Noctuidae)

Investigation undertaken with eight chickpea genotypes (Vallabh Kallar Channa 1, Ankur (CSJ 140), JGK-2, Ganguar (GNG 1581), Jawahar Gram-1 (JGK 1), WCG-10 (Pant G-10), Avrodhi and ICC 506-EB as resistant check) for their morphological and biochemical traits of resistance to Helicoverpa armigera, indicated trichome number, length and density, and nitrogen, total chlorophyll and potassium content as influencing the resistance/ susceptibility levels in chick pea.

Factors Affecting Adult Captures of the Cotton Bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Pheromone-Baited Traps

The effects of funnel-trap color, trap height and pheromone formulation on the adult captures of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) were evaluated in traps that were suspended in cotton fields in central Greece. Briefly, in a first trial, the efficacy of funnel traps of three different colors, i.e., green, striped (with black and white stripes) and white, was comparatively evaluated, whereas in a second trial green funnel traps were placed at three heights, i.e., 30, 60 and 90 cm from the ground. Finally, in a third trial we tested the efficiency of green funnel traps with three commercially available pheromone lures. Considering the overall captures, trap color and pheromone formulation affected male captures, whereas trap height had no influence. Captures notably increased in all traps from late August to mid-September. In total, the white funnel trap captured more moths than the green or striped funnel traps. Placement of the traps at different heights did not significantly affect captures, but seasonal differences were observed at individual dates during the trapping period. Barrettine’s pheromone lure provided significantly more captures than the other two (Russell, Trécé) in some of the trap-check dates. The results can be further utilized in the monitoring protocols of H. armigera in cotton fields.

Prediction of Helicoverpa armigera (Hubner) larval population using weather based forewarning model in soybean

Weekly larval populations of pod borer, Helicoverpa armigera (Hubner) collected from 20 districts of Maharashtra under Crop Pest Surveillance and Advisory Project (CROPSAP) during 2010-2015 were analyzed to work out the effect of weather variables on the incidence of this insect on soybean. The appearance of larva was observed throughout the soybean growing season, and the peak incidence was observed during third week of August to first week of September (34-35 SMW). The correlation analysis of the data revealed that larval population was significantly and positively influenced by the minimum temperature and rainfall of current week as well as previous two weeks. For the development of forewarning model, data for the period from 2010 to 2013 were used as training dataset and two year (2014-2015) data as validation dataset. The mean model used for forewarning the incidence of pod borer larval population was developed by using step-wise multiple regression analysis in polynomial form. The results of mean model revealed that the significant variables affecting the pod borer larval population in soybean were maximum temperature (current and 1st lag week), and rainfall (current week) and the model explained 48.93% variation. The pre-disposing conditions for the incidence of larvae have been worked out as maximum temperature ranging from 26.1 to 31.47 ºC and rainfall ranging from 6.63 to 141.46 mm with low or medium rainfall in previous weeks followed by high in current week. The model was validated with 2014-15 independent dataset with predicted R2 (R2 ) value 28.13%. Two sample t-test showed no Pred significant difference between observed and predicted values (p = 0.3691 > 0.05).

​Bio-efficacy of Chemical Insecticides and Biopesticides against Gram Pod Borer, Helicoverpa armigera (Hubner) and Spotted Pod Borer, Maruca testulalis (Geyer) on Greengram, [Vigna radiata (L.) Wilczek]

Background: Gram pod borer, Helicoverpa armigera (Hubner) and spotted pod borer, Maruca testulalis (Geyer) are important pod boring insects infesting the greengram, [Vigna radiata (L.) Wilczek] throughout the India. A number of synthetic insecticides are known to be effective against these borers but most of them have been phased out as a result of high toxicity to the pollinators and other biotic fauna, therefore, a group of new chemical insecticides with biopesticides have been tested for bioefficacy against these insect pests. Method: A field experiment was conducted at S.K.N. College of Agriculture, Jobner, Rajasthan during kharif, 2018 in randomized block design (RBD) with 9 treatments and 3 replications. The observations were recorded of Helicoverpa armigera (Hubner) and spotted pod borer, Maruca testulalis (Geyer) borers one day before and 1, 3, 7 and 15 days after application of insecticides and biopesticides in each the spray from ten randomly selected and tagged plants/ plot. From the data recorded per cent reduction in population over control was calculated. The per cent pod damage was calculated by counting damaged pods out of healthy pods of greengram. Result: The spinosad 45 SC (0.01%) proved to be most effective, indoxacarb 14.5 SC (0.01%) followed by fipronil 5 SC (0.01%), whereas, treatments of neem leaf extract (10.00%), Beauveria bassiana 1.15 WP 1X108 spore/ l proved to be least effective. The maximum seed yield of 9.13 q ha–1 was obtained in the plots treated with spinosad 45 SC (0.01%) followed by indoxacarb 14.5 SC (0.01%) (8.89 q ha-1), fipronil 5 SC (0.01%) (8.60 q ha-1).