Varietal Differences in the Population Trend of Lipaphis Erysimi Kalt in Canola

Abstract

The present study was conducted to investigate the varietal differences in the population trend of Lipaphis erysimi kalt. in canola field at the Agriculture Research Institute Tarnab, Peshawar, during 2022. Five canola varieties, namely Raya, NARC, Champion, Zahoor, and Rokhana, were evaluated to determine their susceptibility to aphid infestation. Data on aphid population were recorded weekly from January to April 2023. Significant differences were observed among the tested varieties regarding aphid infestation levels. The lowest mean aphid population per leaf (5.23) was recorded on the NARC variety, indicating comparatively higher resistance, whereas the highest mean population (7.53 aphids leaf⁻¹) was observed on the Raya variety, suggesting greater susceptibility to aphid attack. Aphid populations remained low during the early growth stages of the crop and increased progressively with time, reaching a peak during the first week of March. The maximum aphid population (31.62 aphids leaf⁻¹) was recorded on the Raya variety, while the overall highest weekly mean population across all varieties was observed during the first week of March (26.36 aphids leaf⁻¹). Thereafter, the aphid population declined gradually toward crop maturity. The results indicate that canola varieties differ significantly in their response to L. erysimi infestation, with NARC showing the greatest tolerance and Raya the highest susceptibility. These findings provide valuable information for selecting suitable canola varieties and developing integrated pest management strategies for sustainable canola production.