Effect of Different Growing Environments of Pigeonpea Cultivars on Population Dynamics of Clavigralla gibbosa and its Relationship with Microclimate

Abstract

The field experiment was carried out at research farm of Department of Agricultural Meteorology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, during Kharif season 2017-18 to study the influence of different growing environments on Clavigralla gibbosa population dynamics and its relationship with microclimate of pigeonpea cultivars. The results revealed that the egg masses and adult population of C. gibbosa were first recorded during the 38th SMW and continued until crop harvesting in all cultivars and D1 (First fortnight of May), and D2 (First fortnight of June) sown crops, whereas it was observed during the 40th SMW and 39th SMW in the D3 (Second fortnight of June) sown crop, respectively. Mean number of egg masses of C. gibbosa (0.15 egg masses/plant) and population of adults (1.24 adults/plant) recorded highest under D1 sown crop, whereas, among cultivars, it was found higher (0.15 egg masses/plant) and (1.18 adults/plant) under cultivar Paras. The nymphal population of C. gibbosa initially noticed during 38th SMW in Manak cultivar sown on D1 and D2, while, in cultivars Paras and UPAS-120, it was noticed during 39th SMW and in D3 sown crop on 40th SMW. Among different date of sowings, higher nymphal population (0.22 nymphs/plant) was found in D1 sown crop while among different cultivars, it was highest (0.21 nymphs/plant) on cultivar Manak. Non-significant negative correlation was obtained between egg masses laid by C. gibbosa and temperature while non-significant positive correlation was obtained with relative humidity in cultivar Manak. In cultivar Paras, non-significant positive correlation with temperature while non-significant negative correlation with relative humidity. In cultivar UPAS-120, non-significant positive correlation was found with both temperature and relative humidity. Significant negative correlation was obtained between nymphal population of C. gibbosa and temperature while relative humidity showed significant positive correlation with tur pod bug nymphal population in all three cultivars. Adult population of C. gibbosa showed significant positive correlation with temperature while non-significant negative correlation with relative humidity in all cultivars. A negative linear relationship was found between temperature and nymphal population of C. gibbosa while relative humidity showed positive linear relationship on all the three varities i.e., Manak, Paras and UPAS-120 explaining the variability up to 65 and 49 per cent, 58 and 59 per cent and 53 and 55 per cent, respectively.