Debraj Adhikari^1*, Umesh Kumar Acharya² and Yam Kumari Shrestha^3
1Plant Quarantine and Pesticide Management Centre, Hariharbhawan, Lalitpur
²National Citrus Research Program, Paripatle, Dhankuta ³National Fruit Development Centre, Kritipur, Kathmandu *Corresponding author’s email: adhikari.debraj1@gmail.com

Abstract

From time immemorial, Nepal has been growing citrus as one of its major fruit crops. In addition to supporting grower's livelihood in the hilly region, citrus crop turns out to be prime source of income. According to MoALD out of 50,235 ha only 64.07% citrus orchards are in productive stage with productivity of 9.67 mt/ha. However, the number of productive orchards has been declining and citrus production has plummeted despite the large scope of area expansion and commercialization. A number of biotic factors have threatened the vitality of citrus trees in Nepal, together with the weak orchard establishment and management technology adoption. This study outlines the most significant diseases and insects that pose a threat to citrus cultivation in Nepal. The major diseases in citrus orchards are citrus greening, citrus tristeza virus, phytophthora root rot, sooty mold and powdery mildew. The citrus greening disease has invaded orchards of majority of districts and the extent of disease severity is presented in the paper. Chinese citrus fly, fruit sucking moth, scale insects and mites which were secondary pest in the past are key insects now causing major fruit losses. The past management recommendation for these pests are not working due to tolerance, effect of climate change (movement of Asian citrus psyllid to higher elevation), unavailability and/or banning of previously recommended pesticide while secondary pest resurgence is also evident for some pests (fruit sucking moths, rust mites). To rejuvenate senile orchards, the effort should focus on updating integrated management recommendations and using it for specific pests by all research and development partners.