Insect Diversity on Low Chilling Apple Varieties in Horticulture Experimental Farm of Jorhat, Assam, India

Abstract

Low chilling varieties are those apple varieties which can be successfully cultivated in warm areas with around 200-300 hrs of chilling temperature (below 7oC). Some of the low-chilling apple varieties are Anna, Tropical Beauty, Early Fuji, Tamma, Neomi, Parlin's Beauty, Golden Dorsett, HRMN-99, etc. Apple crops have been infested by a large number of insects, including both harmful and beneficial insects, and some of them are very serious pests and need awareness to control them. The present study aimed to investigate the insects infesting low-chilling apple varieties. A study on “diversity of insects on low chilling apple varieties viz. HRMN-99, Dorsett Golden and Anna” was carried out in the Horticulture Experimental Farm, Assam Agricultural University, Jorhat, India, during 2023-24. Based on taxonomic classification, the insect species were placed into 6 different orders, viz. Coleoptera, Hemiptera, Lepidoptera, Hymenoptera, Heteroptera and Aranea. Major insect pests recorded were woolly apple aphid (Eriosoma lanigerum), shot hole beetle and codling moth (Cydia pomonella) and the remaining 6 species were recorded as minor insect pests. Natural enemies observed were ladybird beetles, braconid wasps and lynx spider, while honey bees visited as pollinators. Also, the prevailing weather conditions of the experimental region, especially during flowering and fruiting stages, and the insects recorded in response to particular intervals of time were presented along with the weather data. The results gathered throughout the study will aid in understanding the biodiversity of insect species linked to low chilling apple plants, thus impacting taxonomy and pest control in apples, especially within the Jorhat area. Consequently, further research may be conducted to obtain a clear understanding of insect pests linked to apple in this area, thus informing pest management approaches. Furthermore, examining the effectiveness of key natural foes is crucial to decrease the reliance on chemical pesticides and protect both them and the pollinators.