Citrus Orchard Care in Nepal's Monsoon: Disease Control & Planting Guide

Canker Disease: The Biggest Threat to Citrus Groves

If you see canker on any branches or leaves in your lime or citrus orchard, remove and burn the affected parts immediately — this disease spreads fast on wind-driven rain. Spray the remaining healthy trees with a mix of 2g copper oxychloride and 2ml kasugamycin per litre of water, repeated every 15 days.

Felt Disease and Pink Disease on Young Branches

When felt disease or pink disease shows up on the finer branches of citrus trees, cut below the affected area and destroy the trimmings, then spray the whole tree with a 1.5% Bordeaux mixture. If the affected branch is already thick, scrub the area with a jute sack and paint it with a 10% Bordeaux paste instead.

Controlling Fruit Flies With Protein Bait

Regular protein-bait spraying is the most effective way to manage the Chinese citrus fly, which causes fruit to rot and drop. Mix one part pesticide-treated protein bait with two parts water, and spray a one-square-metre patch on the lower branch of every third tree, repeating every 10 days. For fruit-sucking moths, which puncture fruit and cause it to fall, regularly inspect trees and fruit clusters and hand-pick and destroy any moths found clustered together — they're easiest to control before they disperse.

Root and Collar Rot After Heavy Rain

If you notice root or collar rot in fruit trees, cut away and remove the rotted portion, then treat the surrounding root zone twice with a solution of Trichoderma viride or Pseudomonas fluorescens (10g per litre of water).

Planning a New Orchard: Spacing Guide

Since this is planting season for citrus and other fruit saplings, mark out your orchard layout and prepare planting pits now — a square or hexagonal grid on flat land, or contour planting on sloped ground. Recommended density per ropani:

• Orange: 5–6m spacing, 15–20 trees per ropani
• Lime: 4–5m spacing, 20–30 trees per ropani
• Avocado: 8–10m spacing, 5–8 trees per ropani
• Litchi: 10m spacing, 7–8 trees per ropani
• Mango: 10–12m spacing, 5 trees per ropani (Amrapali variety: 5m spacing, 20 trees)
• Banana: 2–3m spacing, 50–55 plants per ropani (dwarf varieties: 2m spacing, 125 plants)

If you're growing grafted citrus, regularly remove any rootstock suckers growing below the graft union — left alone, they'll draw energy away from the grafted variety you actually want to fruit.