Journal of FARM SCIENCES, Vol 32, No 1 (2019)

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Studies on the relationship of weather on pod borer damage in soybean

MAHESH HAROLI, H. VENKATESH

Abstract


A field experiment entitled “Studies on relationship of weather on incidence of insect pests in soybean” wasconducted during kharif season of 2017 at the Main Agricultural Research Station (MARS), Dharwad, Karnataka, India. Byproviding staggered sowing windows three different growing environments (GE) were created for the soybean crop. Thishelped in creating different environmental conditions to facilitate prevalence of pod damage. The pod damage was lowest inGE1 (5 %) at 80 Days after sowing (DAS), whereas highest in case of GE3 (41 %) at 87 DAS and it was intermediate in GE2(27 %) at 87 DAS. Regression analysis was performed for estimating the pod damage using weather variables as independentparameters, three days lead time (LT3), seven days lead time (LT7) and dynamic modelling by combining real time (LT0),three days lead time (LT3) and seven days lead-time (LT7). variable X20 (afternoon absorbed photosynthetically activeradiation (PAR) in the crop canopy) at real time (LT0), variable X25 (diurnal range in air temperature at bottom of thecanopy) at three days lead time (LT3), variable X31 (Rainfall) at seven days lead-time (LT7) and in the dynamic model theresults indicated that out of three variables, two variables viz., X20 (afternoon absorbed PAR in the crop canopy) of leadtime zero (LT0) and X25 (diurnal range in air temperature at bottom of the canopy) of three days lead time (LT3) wereconsidered weather parameters in the optimised model which are important for forecasting pod borer damage.

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