Studies on seasonal incidence of sucking pests and pink bollworm, <em>Pectinophora gossypiella</em> (Saunders) in cotton (<em>Gossypium </em>spp.)

Abstract

A field experiment was conducted at AICRP on cotton, Haradanahalli, Chamarajanagara during kharif 2018 to know the population dynamics of insect pests of cotton on HB2110 cultivar. The peak incidence of aphids (64.28 aphids/3 leaves), leafhoppers (5.24 leafhoppers/3 leaves), thrips (5.51 thrips/3 leaves) and whiteflies (4.97 whiteflies/3leaves) were observed during 36, 28, 40 and 38 th SMW. Pink bollworm incidence was started during 32 SMW and attended its severity at 46 th (15 larvae/20 bolls).The correlation results of the meteorological variables with insect population revealed that aphids, thrips, whiteflies and PBW showed significant positive correlation with maximum temperature while, leafhopper showed positive non-significant correlation. However, all the above pests showed nonsignificant negative correlation with minimum temperature, evening relative humidity and rainfall except leafhopper and aphids showed significant positive correlation and non-significant negative correlation with morning relative humidity, respectively.

Influence of abiotic factor on incidence of Pink bollworm, Pectinophora gossypiella (SAUNDERS) on Bt cotton

“…However, the peak green boll damage was observed in 46 th , 47 th and 48 th MW. Divya et al (2020) [5] reported that the pink bollworm incidence was started during 32 nd SMW and attended its severity at 46 th (15 larvae/20 bolls). In the present study, the pink bollworm population was at the highest level during 46 th SMW (23 th WAS), while damage on flower and bolls was during 40 th SMW (17 th WAS) and 44 th SMW (21 st WAS), respectively.…”

“…Whereas green boll damage had positive correlation with minimum temperature but nonsignificant (Shravan et al, 2017) [11] . Divya et al (2020) [5] reported that the correlation results of the meteorological variables with insect population revealed that pink bollworm showed significant positive correlation with maximum temperature and non-significant negative correlation with minimum temperature, evening relative humidity and rainfall. In present findings more or less similar trend is observed, hence our findings are accordance with the findings of earlier researches.…”