Paddy catches fungus with fears of heat shock rising amid heatwave in Bangladesh

BRRI has warned farmers about the possibility of heat shock ruining the grains and asked them to retain water in the croplands

Shahariar Nobelbdnews24.com
Published : 17 April 2023, 09:21 PM
Updated : 17 April 2023, 09:21 PM

As farmers languish over rice blast fungus in BRRI dhan 28 variety of paddy in the Haor region, an unrelenting heatwave has triggered fresh fears of poor harvest in the Boro season due to heat shock.

Bangladesh Rice Research Institute sounded an alarm with maximum daily temperatures hovering around 40 degrees Celsius in Bangladesh.

Extreme temperatures hinder the formation of grains at the stage of paddy maturing, causing most grains to remain semi-nourished and affecting the overall quality of the harvest.

The institute advised farmers to keep 2-3 inches deep water in the fields until the grains inside the paddy solidifies.

The Department of Agricultural Extension set a target of cultivating paddy across 4.97 million hectares this season. The production target was set at 210,000 tonnes of rice.

Farmers in Habiganj, Moulvibazar, Sunamganj, Sylhet, Netrakona, Kishoreganj and Brahmanbaria districts cultivated paddy across 661,900 hectares of Haor land.

However, reports poured in from Moulvibazar, Netrakona, Kishoreganj, Munshiganj and several other areas that most of the BRRI dhan 28 paddy, known as BR 28 or only Athash, suffered fungal infection.

“Varieties invented earlier are affected by blast fungus. Athash is an older type of paddy and is more prone to blast,” said Md Abdul Latif, chief scientific officer at BRRI’s Plant Pathology Division.

“The fungus is so deadly that preventive measures are required to keep the paddy healthy. But farmers do not take those measures before the crops are affected. If steps are not taken before flowers bloom and blast forms in the paddy, it can no longer be saved.”

The paddy at final stages of ripening might also catch fungus with temperatures as high as 40 degrees Celsius, Latif said.

“We issued a warning, asking farmers to retain water for plants that have flowers and are in the final stages of ripening, so that the paddy don’t burn up in any way.”

The paddy might be ruined due to excessive heat, he added, but retaining water for crops yet to reach maturity would help prevent fungal infestation.

WHAT IS HEAT SHOCK?

The Boro crop season begins in November, around Kartik-Agrahayan Bengali months, and ends in the scorching summer heat of April-May, the Bengali months of Baishakh and Jaistha.

Paddy plants cannot tolerate temperatures above 35 degrees Celsius. If such temperatures continue for 1-2 hours when flowers bloom, grain formation is ruined. This is called a heat shock.

BRRI officials said nor’westers often occur during such heatwaves. The shock is not as effective if it rains either. But continuous heatwaves for such a long time result in a heat shock. Heatwaves without rain cause the paddy flowers to dry up.

In 2007, a heat shock occurred amid a heatwave. Then again in 2021, a heat shock lasting several hours ruined paddy across 21,000 hectares of land.

The BRRI warning mentioned paddies with flowers discharge a lot of heat in the water during pollination and the blooming process. It works as a physiological cooling system of the crops. So retaining 2-3 inches of water on harvest lands until the grains solidify is the best way to save the crops from heat shock amid extreme temperatures.

DRIED GRAINS RUIN ANNUAL PROVISIONS

Farmers in the Haor region have already started reaping BR 28 paddies but BR 29 types are still in the fields.

Agricultural officials in the Haor districts said massive amounts of Boro crop was cultivated until now due to favourable conditions. The paddies turned golden in colour, raising hopes of sweeping yields.

But many BR 28 fields were infected with blast fungus, dashing the farmers’ dreams of a bumper production.

Sony Ahmmed, a farmer from Netrakona’s Madan Upazila, said: “My Athash grains have all dried up. None of the paddies are suitable for harvest anymore. It’s a complete loss. I spent Tk 45,000 and now won’t get any money back.”

The farmers of the nearby Upazilas of Mohanganj, Khaliajuri and Kishoreganj suffered similar fates.

Hatim Mia, a farmer from Bangalpara Union in Kishoreganj’s Austagram Upazila, said: “The situation is very dire this year. All the grains of Atash paddy are ruined. The agriculture office spoke about some medicines. But those are not working. I yield 80,000 kg of paddies. But this year I won’t get even half of that.”

Another farmer from the area, Shahi Ullah said: “We had a paddy variety called Paijang before. It delivered good yield for 10-12 years but was later ruined. The harvest was not good after we cultivated Athash last year. This year, they’re in ruins. The agricultural officials did not even visit the fields to have a look.”

Md Abdul Matin, the agricultural officer of the Upazila, said: “The paddies were ruined due to the weather. We experienced fog late into the day in this area a few days ago with a lot of difference in day-night temperatures.”

“It’s ideal for blast fungus infestation. We’ve told the farmers which medicinal spray to use to cure this. They tried to do it. But many were not able to use the spray during the rains some days ago.”

Matin cited a “lack of manpower” for not being able to inspect the fields and visit the farmers.

DANGERS OF HEAT SHOCK

Although BRRI sent warnings in advance about heat shock, farmers said agricultural offices had not provided them with details. They said they have to work with the knowledge from experience.

Ali Haider, a farmer from Banshari village of Madan Upazila, said he planted five types of paddies on his land. “All of them, barring BR 29, have matured. I’m retaining water on the BR 29 field. The heat is yet to harm my crops.”

Haider said he did not receive any instruction from the agricultural office and had to rely on his experiences. His son Anas, who is a higher secondary student, said: “We get necessary information from Facebook and the news. The officers did not tell us anything.”

“We needed to irrigate the BR 29 fields, but we couldn’t due to a lack of electricity.”

However, agriculture officials said they were trying to relay the information to farmers.

Md Habibur Rahman, agriculture officer at Madan Upazila, said: “The rain a few days ago brought water to the fields. We’ve also spoken with the Rural Electrification Board, regularly asking them to continuously supply power for irrigation in higher areas.”

“We’re in contact with the farmers and are going to the fields. I went to the fields today as well and asked them to retain 2-3 inches of water.”

Swapan Kumar Khan, an additional director at the Department of Agricultural Extension, shrugged off complaints over officials not visiting the fields.

“This is not true. Every union has three officers. But there’s a lack of manpower in many places and we are recruiting.”

[Writing in English by Syed Mahmud Onindo; editing by Osham-ul-Sufian Talukder]