IIHR Develops Disease-Resistant Rootstock for Watermelon Farmers

Scientists at the Indian Institute of Horticulture Research have developed a hybrid watermelon rootstock called Arka Shakti, which is resistant to Gummy Stem Blight, a fungal disease affecting the crop. The rootstock was developed by IIHR’s Vegetable Science department. Principal Scientist Sreenivasa Rao said the disease is a major problem because it can spread through seed, soil and air.

While chemical treatment can address seed and aerial infection, soil infection is more difficult to control. Arka Shakti is an interspecific cross between Citrullus amarus and Citrullus lanatus. Scientists said farmers can graft varieties purchased from the market onto the rootstock, allowing them to continue using existing watermelon seeds.

Rao said the disease often becomes a problem when watermelon is grown repeatedly in the same soil without crop rotation. He linked the disease to a reduction in Karnataka’s watermelon cultivation area, which he said fell from 12,000 hectares in 2014 to 1,300 hectares in 2024. The grafting can be carried out by nurseries with the required facilities and skilled workers.

Rao said nurseries charge ₹6 to ₹8 per plant. For a farmer spending ₹60,000 to cultivate one acre, using grafted plants would add about ₹15,000 to the cost. IIHR has cultivated a small quantity of watermelons using Arka Shakti.

Rao said the fruit showed good colour and sweetness and weighed between three and eight kilograms, depending on the variety. The institute plans to train interested nurseries across India so the rootstock can reach farmers commercially.