1Acharya N.G. Ranga Agricultural University, Andhra Pradesh, India
2Professor Jayashankar Telangana State Agricultural University, Hyderabad, Telangana, India
3YSP University of Horticulture & Forestry, Solan, Himachal Pradesh, India
4International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Hyderabad, Telangana, India
*Email: vcuhf@yspuniversity.ac.in
Online published on 23 December, 2020.
Pest incidence in chickpea was studied across sowing dates to understand the effect of climatic factors on pest incidence on five genotypes of chickpea. The egg laying by the pod borer, Helicoverpa armigera decreased across sowing dates from October to December, with a slight increase in oviposition was observed in the January sown crops. ICC 3137 was most preferred for egg laying (9.5 eggs/5 plants), followed by KAK 2 (6.8 eggs/5 plants). The incidence of H. armigera decreased with a delay in time of sowing (60.0 larvae/ 5plants in the October sown crop to 21.9 larvae/5plants in the December sown crop). However, a slight increase was observed in the January sown crop (34.8 larvae/5plants). The highest incidence of H. armigera larvae was recorded on ICC 3137 (55.1 larvae/5plants), and the lowest on ICCV 10 (29.9 larvae/5plants).The numbers of H. armigera larvae were negatively correlated with open pan evaporation, temperature (both maximum and minimum), wind velocity and solar radiation in all the chickpea genotypes, except in ICCV 10. However, oviposition by beet armyworm, Spodoptera exigua was positively correlated with open pan evaporation, temperature (both maximum and minimum), and solar radiation in ICC 3137 and ICCV 10. The abundance ofS. exigua larvae was significantly and positively correlated with rainfall, open pan evaporation, temperature (both maximum and minimum), wind velocity and solar radiation, except in ICCV 10, which showed a non-significant negative correlation. The pod borer damage was significantly and positively correlated with rainfall, open pan evaporation, temperature (both maximum and minimum), wind velocity and solar radiation, suggesting the global warming will lead to an increase in pest incidence in chickpea. The numbers of H. armigera larval parasitoid, Campoletis chlorideae cocoons were significantly and negatively correlated with rainfall, open pan evaporation, temperature (both maximum and minimum), wind velocity and solar radiation, indicating that increase in temperature will decrease the efficacy of natural enemies. Grain yield decreased with an increase in rainfall, open pan evapouration, temperature (both maximum and minimum), wind velocity and solar radiation, but was positively correlated with relative humidity. The present studies suggested that global warming will decrease the incidence of H. armigera, but with result in an increase in the incidence of S. exigua. Increase in temperature will also decrease the extent of parasitization of H. armigera, which will result in a significant decrease in crop yields. Therefore, there is a need to develop strategies to mitigate the effects of climate change on crop production and food security.
Chickpea, Climate change, Helicoverpa armigera, Pest incidence, Spodoptera exigua
