Vol. 11, Issue 9 (2022)

Author(s):
NK Kavad, KA Patel, NV Radadiya, KM Patel and VA Patil

Abstract:
In a field experiment on study the population dynamics of rice leaf folder, Cnaphalocrocis medinalis on rice in relation to weather parameters during Kharif 2020 to 2021. Result revealed that the maximum number of larvae (11.22) were observed during third week of September (38^th SMW), while minimum number of (0.88) larvae were observed during third week of October (42^nd SMW). Per cent damaged leaves and weather parametres indicated that maximum per cent damaged leaves (20.19%) were observed in fourth week of September (39^th SMW) and that of minimum per cent damaged leaves (0.98%) were noticed during fourth week of October (43^rd SMW). Then after it was disappeared in next SMW. Thus, the findings refer that per cent damaged leaves caused by leaf folder was observed during 31^st SMW to 43^rd SMW while, number of larvae observed during 31^st SMW to 42^nd SMW. Highly significant negative association was found between maximum temperature (-0.6827) and sunshine hours (-0.6767) with number of larvae and highly significant negative correlation was found between maximum temperature (-0.6494) and sunshine hours (-0.6575) with per cent damaged leaves. Positive relationship of humidity was found with the number of larvae and per cent damaged leaves. Highly significant positive correlation was found between maximum relative humidity (0.6321) while significant positive correlation was found between minimum relative humidity (0.5471) with number of larvae and in case of per cent damaged leaves, maximum relative humidity (0.6469) was found highly significant positive while minimum relative humidity (0.5612) was found significant positive whereas, Minimum temperature had non-significant negative correlation while rainfall and rainy days were found non-significant positive correlation with the number of larvae and per cent damaged leaves.