Sun burn injury is commonly noticed in some parts of Indian states (Southern India, Rajasthan, Gujarat, Maharashtra and Kolkata) where the summer temperature goes beyond 38 °C. Symptoms appears during March and April when the day and night temperature records wide variation, particularly the temperature crosses above 38 ºC. High radiation level gives plants a bleached appearance (caused by destruction of chlorophyll in stems); reduced growth and plants may eventually die if no control measure is taken. The intensity of sun burn on western side of plant stem varies between 10−50 %. Even complete loss of orchard can happen due to sun burn followed by aggravating the stem rot diseases. Hence, timely detection and necessary precautions are needed at farmers’ end to protect the dragon fruit crop.
Adaptive measures
Spray of anti-transpirants [Kaolinite (50 g per litre of water) + Neem soap (4 g per litre of water) along with Sea weed extract and Humic acid (4 ml per litre of water)] during the month of January, March and April. It also reduces the sun burn damage, fungal and bacterial infection.
Irrigation of dragon fruit orchard (8-10 lt/pole) increases the crop’s tolerance to Sun burn injury.
