Seasonal incidence of major insect pests of pigeonpea (Cajanus cajan L.) under field conditions

Abstract

The present investigation entitled “Seasonal Incidence of Major Insect Pests of Pigeonpea (Cajanus cajan L.) under Field Conditions” was conducted during the Kharif season of 2024-25 at the Research Farm, RAK College of Agriculture, Sehore (M.P.). The pigeonpea variety TJT-501 was sown on 20th July 2024 with a spacing of 60 × 20 cm. Observations on the seasonal incidence of major insect pests, including defoliators (leaf webber, plume moth), sucking pests (jassids, green stink bug, pod bug) and pod-infesting pests (pod borer, pod fly), were recorded once in a standard week from 10 randomly selected plants per plot using the visual search method. Pod fly infestation was assessed by splitting 50 pods per plot, while jassid counts were taken from six leaves representing the top, middle and lower canopy. The results revealed that jassid (Empoasca kerri) appeared from the 35th SMW to 1st SMW with a low population and showed a positive but non-significant correlation with maximum temperature. Leaf webber (Grapholita critica) persisted from the 33rd to 47th SMW, peaking in the 44th SMW (3.1/plant), and was significantly positively correlated with maximum temperature. Plume moth (Exelastis atomosa) appeared from the 42nd to 52nd SMW, peaking in the 49th SMW (4.9/plant), with non-significant negative correlations with all-weather parameters. Pod bug (Clavigralla gibbosa) was observed from the 43rd to 52nd SMW, peaking in the 50th SMW (4.8/plant) and showed significant negative correlations with both temperatures. Pod borer (Helicoverpa armigera) occurred from the 41st SMW to 1st SMW, with a peak of 6.6/plant in the 50th SMW, and was significantly negatively correlated with minimum temperature. Pod fly damage was recorded from the 49th SMW (30%) to 4th SMW (74%), showing significant negative correlations with maximum temperature and relative humidity.