Seasonal incidence of Earias spp. and their natural predators on okra [Abelmoschus esculentus (L.) Moench] in Hiper arid region of Rajasthan Yadav Surendra Kumar1,*, Kumawat K.C.2, Ram Nema3 1Assistant Professor (Entomology), College of Agriculture (SKRAU) Bikaner, Rajasthan, India 2Professor, SKNAU, Jobner, Jaipur, Rajasthan, India 3Assistant Professor (Entomology), College of Agriculture, Sumerpur (AUJodhpur), Rajasthan, India *Email: yadavravivihar@gmail.com
Online Published on 16 September, 2023. Abstract The seasonal incidence of borer, Earias species and their predator on okra were studied at an experimental farm of College of Agriculture, Bikaner Rajasthan. The commencement of shoot borer on okra was observed in the 2nd and 3rd week of August during 2013 and 2014 respectively. The shoot borer reached its peak in the 3rd and 5th week of September during 2013 and 2014, respectively. The infestation of shoot borer disappeared from shoots during 3rd and 4th week of October during 2013 and 2014, respectively. The correlation between shoot borer infestation and maximum, minimum temperature and relative humidity showed non-significant effect in both the years. The fruit damage commenced in the 34th SMW (fourth week of August) and reached peak both number and weight basis in third week of November during both the years of study. The correlation of borer on fruits based on number basis exhibited a negative and significant effect with maximum temperature (r= -0.76) minimum temperature (r= -0.92) and mean relative humidity (r= -0.56) during 2013. The infestation of fruit borer based on number basis showed quite similar trend of correlation during 2014, which was significant negative with maximum temperature (r= -0.81), minimum temperature (r= -0.77) and mean relative humidity (r= -0.70). A negative significant correlation were observed between maximum temperature (r= -0.76), minimum temperature (r= -0.93) and mean relative humidity (r= -0.57) during 2013 on weight basis. Similar observations were recorded during 2014 i.e., maximum, minimum temperature and mean relative humidity showed negative significant correlation with fruit damage on weight basis (r=-0.81, r=-0.79 and r=-0.70 respectively). The population of predator, Coccinella spp. started in the first week of August and reached to its maximum in the fourth week of September during 2013 and 2014. The populations of Chrysoperla commenced in 33rd and 32nd SMW during 2013 and 2014 respectively and reached peak in the fourth week of September during both the years. The nonliving factors i.e., abiotic factors did not affect the predator in present investigation during 2013 and 2014 except the rainfall exhibited (r= -0.61) negative significant effect on Chrysoperla population during 2013. Top Keywords Okra, Seasonal incidence, Shoot, Fruit borer, Predator. Top |