IIHR scientists’ disease-resistant variety rescues vine vegetables

Bengaluru: Sourcing its share of vegetables from surrounding districts and adjoining Andhra Pradesh, Tamil Nadu, Bengaluru suffered a jolt when the gummy stem blight infection — a rare disease threatened to wipe out the vine variety of vegetables in 2017-18. What initially started around Bengaluru soon spread to the whole of country, affecting the production of vegetables like bottle gourd, bitter gourd, ivy gourd, ridge gourd and even impacted the cultivation of watermelon, cucumber and muskmelon, forcing farmers to use high doses of pesticides.

Scientists at Bengaluru-based Indian Institute of Horticultural Research (IIHR) at Hesaraghatta discovered that the infection was due to increased soil moisture from untimely rain in winter months and embarked on a mission to develop a variety resistant to this stem rotting disease. "It took us about a year to discover the genetic material from our germplasm, which has resistance to this stem rot disease," said Prof MV Dhananjaya, principal scientist at IIHR's vegetable crop division, who developed the new variety of bottle gourd — Arka Shreyas.

"Bottle gourd is one of the very few varieties of vegetables available throughout the year in Bengaluru market at affordable price. We worked extensively and developed the new variety in 2021-22," Dhananjay said.

The scientists tried the new variety at a field near Anekal, southeast of Bengaluru in 2022-23. "Farmers gave up cultivation of vine variety of vegetables due to this disease. Yet, we convinced them to try our new variety Arka Shreyas. Despite the untimely rains in 2023 and 2024, it withstood the excess moisture in the soil without any trace of the virus and doubled the yield per hectare," he said.

Farmers reaped 55-50 tonnes per hectare with a few even getting 75-80 tonnes per hectare. The new variety not only cheered farmers with good profits but also ensured affordable prices at the market. "The new variety of bottle gourd has longer shelf life of 10 days, and each fruit weighs about 900gm to 1.2kg. Unlike the earlier elongated shape, the small and bottle shape of the new variety also impressed consumers. Now the same gene material is used to develop other varieties of vine vegetables resistant to this gum blight disease," added Dhananjaya, who won the Kalaiah Krishnamurthy national award for the new variety.