A new biocontrol agent to manage ‘foot rot’ disease in Basmati crop: Why this matters

Foot rot, and current management practices

Rice is cultivated in two stages. Seeds are first sown in a nursery bed, where they sprout and grow into seedlings, which are then transplanted into a well-puddled and prepared field. Foot rot is a fungal disease that affects Basmati rice crops particularly at the seedling stage, though it might also cause infection after transplantation in case infected seedlings are transplanted.

It is caused by the fungus Fusarium verticillioides, a soil-seed borne pathogen which spreads the infection through the root of the plant, and eventually leads to the colonisation of the stem base, Dr Amrik Singh, Chief Agriculture Officer, Faridkot told The Indian Express. Infected seedlings first turn pale yellow, then elongate and dry up, and eventually (usually) die.

To prevent the disease from occurring and spreading, farmers resort to early seedling treatment, try and use disease-free seeds, and destroy infected seedlings. Timely seed nursery management is crucial — experts recommend seed sowing in the first fortnight of June, and transplantation in July. Sowing in May often leads to problems as the month’s high temperatures are favourable to the disease. Fields where the nursery is being set up must also be well-drained, with proper irrigation, to avoid the spread of foot rot.

Currently, seedlings are treated with Trichoderma harzianum before sowing and transplantation. Seeds are also treated with fungicides such as Sprint 75 WS (carbendazim + mancozeb) before sowing. But these are the chemical treatments which are harmful for the soil, and can be toxic for consumers of the rice. The fungicide carbendazim is already banned in Punjab because it leaves behind high residues.

PAU’s solution to tackle foot rot

This is where PAU’s newly-developed biocontrol agent comes in. Dr Satbir Sing Gosal, Vice-Chancellor of PAU, highlighted the eco-friendly nature of Trichoderma asperellum, developed jointly by Dr Narinder Singh and Dr Daljeet Singh Buttar. This biocontrol agent offers a non-chemical alternative to traditional pesticides, aiding in disease management while minimising environmental harm, he said.

Speaking to The Indian Express, Dr Buttar said that the prevalence of foot rot in the Basmati crop reduces yields and threatens the state’s export prospects. “In some cases, farmers need to uproot their entire transplanted seedlings,” he said.

According to Dr Buttar, the use of Trichoderma asperellum showed “excellent results” during the experimental phase, as a means to combat foot rot “without leaving harmful residues on the crop” and “compromising environmental safety”. “We advised farmers to treat both the seeds and the seedlings in this agent,” he said.

The challenge now is to ensure the distribution of this agent among farmers, agri-experts point out. Dr Buttar says that an MOU has been signed with a private company for the large-scale manufacturing and distribution of Trichoderma asperellum, with the aim of making it available to farmers from the coming season. This would be a major development in Punjab, which, along with Haryana, accounts for more than 70% of India’s basmati exports.