Population Dynamics of Aphid, Lipaphis pseudobrassicae (Davis) Infesting Broccoli

Abstract

In order to study population fluctuations of aphid infestations in broccoli under middle Gujarat conditions, a Large Plot Technique (Completely Randomized Design) was adopted for the experiment carried out at Horticulture Research Farm, College of Horticulture, AAU, Anand during rabi, 2023-24. The plot was divided into six equal sized quadrates and five plants and three leaves from each plant were selected randomly from each quadrate to record the aphid population. The number of aphids was recorded as low (9.2 aphids/ 3 leaves) and then gradually rose to reach a maximum (72.4 aphids/ 3 leaves) in the second week of February (6th SMW). Subsequently, the population slowly dwindled as the harvest reached maturity. The number of aphids demonstrated a positive relationship with hours of bright sunlight. Additionally, the relationship between the aphids and the maximum temperature was significantly positive. The presence of aphids on broccoli showed a non-significant negative correlation with minimum temperature, morning vapour pressure, evening vapour pressure, morning relative humidity, and wind speed. The relationship between aphids and the evening relative humidity was identified as significantly negative.