There has been no rainfall in the country for several months. Temperatures have been rising since the day after Eid. According to the Meteorological Department’s forecast, a moderate to intense heatwave has affected most parts of the country since April 2.
Yesterday’s weather forecast also mentioned that a mild to moderate heatwave is sweeping through Rajshahi, Dhaka, and Khulna divisions, as well as Dinajpur, Syedpur, Feni, Moulvibazar, Barisal, and Patuakhali districts, and it may continue.
Such a heatwave at the beginning of summer has increased the risk of blast disease in Boro rice, raising concerns about achieving the target rice yield for the season.
The majority of the country’s rice production comes from the Boro season. According to the Department of Agricultural Extension (DAE), the target for Boro rice production this year is 22.6 million tons. Boro rice will be cultivated on 5 million hectares of land, with a target yield of 4.46 tons per hectare. Rice ears have started to appear in the cultivated land.
The Bangladesh Rice Research Institute (BRRI) has issued an early warning and a special bulletin to protect rice from heat waves. The bulletin lists the districts most at risk from the heatwave. These include Tangail, Rajbari, Manikganj, Faridpur, Kushtia, Joypurhat, Naogaon, Chapainawabganj, Rajshahi, Natore, Bogura, Sirajganj, Pabna, Meherpur, Chuadanga, Magura, Jhenaidah, and Jashore.
The bulletin advises farmers to keep 5-7 centimeters of water on the fields at all times to prevent damage to the rice due to the heatwave and warns against any water shortage. The heatwave has raised concerns about the risk of rice blast disease, especially during the flowering stage.
If the rice is infected, 8 grams of Trooper or 6 grams of native mixed in 10 liters of water should be sprayed twice at five-day intervals before the disease symptoms appear.
Experts say that the lack of rain and rising temperatures increase the blast risk. Even after the rain, the disease could spread, leading to a higher number of empty grains. Therefore, preventive spraying is necessary.
There is also a risk that the rice plants may tilt if a Kalbaishakhi storm occurs, leading to leaf drop disease. Farmers need to stay alert.
Agriculture in the country is highly dependent on nature, and experts emphasize the need to stay aware of the weather. Professor Abu Noman Faruq Ahmed, chairman of the Plant Pathology Department at Sher-e-Bangla Agricultural University, told Bonik Barta, “If the temperature rises further, the risk of empty grains will increase, threatening overall production. If a blast occurs, it will spread even after rain. Therefore, farmers should spray Trooper or Nativo as a preventive measure. This is a common suggestion. However, a Baishakhi storm or rain could damage the rice plants. They might tilt, and the leaves could fall. But the risk will also decrease once the temperature drops after good rainfall.”
According to the Bangladesh Rice Research Institute, the fungus causing blast disease can attack rice plants at any stage. The disease first causes very small oval-shaped spots on the leaves. The center of these spots becomes wider and turns grey. The affected leaves can die. Blast disease can also attack the nodes of the rice plant’s stem. The nodes rot, turn black, and break easily. The base of the panicle or ear can also be affected, leading to a panicle blast, where the affected part turns black and breaks. High nitrogen fertilizer and humidity in the air increase the severity of the disease. Cold nights, hot days, and morning dew also promote the disease. The rice plants can dry up and collapse when the disease spreads widely in the field. To prevent this, the Bangladesh Rice Research Institute advises always maintaining water in the fields.
The 2023-24 fiscal year, the country’s Boro rice production was 21 million tons. In the 2022-23 fiscal year, it was 20.7 million tons; in 2021-22, it was 20.1 million tons; and in 2020-21, it was 19.8 million tons.
Agricultural market analysts say proper irrigation is impossible this year due to the prolonged drought. On one hand, there are power outages, and on the other, fuel prices are high. The cost of pesticides has also increased several times, limiting their use. The high price of fertilizers has led to less usage. Therefore, if a blast occurs, production could be affected.
Agricultural economist Dr. Jahangir Alam told Bonik Barta, “There is a risk of blast due to the heatwave. There is medicine available for it. However, if it occurs, it will negatively impact production. We haven’t seen much blast yet, but rice is starting to flower. However, there is no rain. This is a big problem. People in the villages are praying for rain. If it rains, the yield will improve.”
Blast occurs in Boro and Aman rice and wheat. According to agricultural officials, if the medicine is applied on time, the damage to the crop is minimal.
When asked about the government’s preparations to prevent this disease, Md Obaidur Rahman Mondol, director of the Field Wing of the Department of Agricultural Extension, told Bonik Barta, “We are staying alert about this. Farmers are being made aware. Work is being done in every block of the villages. No widespread reports of blast infection have been received yet. If such a situation arises, action will be taken.”