Unknown Disease Hits Aman Paddy in Gaibandha, Farmers Fear for the Harvest

In November 2025 an unidentified disease spread through aman paddy fields in all seven upazilas of Gaibandha district in northern Bangladesh. Jagonews24 reported on 18 November 2025 that the leaves of affected plants dried out and turned brown within two weeks, and that plants were being ruined before their panicles formed. Farmers said the pesticides sold in local markets had not saved the crop, and they warned that if the disease was not brought under control, output would be badly hit and they would face heavy losses. The district office of the Department of Agricultural Extension (DAE) said field officers had collected samples and that the preliminary assumption was bacterial leaf blight, while the department also blamed a lack of rain, a shortage of nutrients and waterlogged fields.

Farmers told the newspaper they had spent Tk 8,000 to 10,000 per bigha on the crop, yet did not expect even one maund of paddy per bigha. They said the disease appeared about two months after transplanting. According to them, no one from the agriculture office had come to advise them or check on the fields, so they had bought pesticides from shops and applied them on their own, without effect. There was no grain on the plants, and they did not know why. Many had planted their aman on borrowed money and had hoped to repay the loans by selling the harvest.

Komol of Rifaitpur in Gaibandha Sadar upazila said: "I planted paddy on borrowed money. Some unknown disease has struck the paddy and nobody can identify it. We will face a big loss on paddy this time."

Chhamchhuljaman Marju of Purba Kumargari in Palashbari upazila said he had planted aman on about five bighas and spent about Tk 50,000 doing so. "The paddy on all of it is ruined. I do not expect a single chhatak of paddy from the five bighas. I applied a lot of pesticide, but it did not work. Even cows will not eat the affected plants. The fields are dying before my eyes," he said.

Abdul Aziz of Halimnagar said: "On my 65 decimals, brown spots first appeared on the leaves, and then the whole leaf dried up. I do not understand what the disease is. I informed the agriculture office; they came and looked, but no effective measure has come yet. There are about 300 bighas in the Tulam beel, and the paddy on all of it is in the same state. We want people from the agriculture office to come and find out why this happened. We want compensation from the government."

Khushi Mia of Bharatkhari village in Saghata upazila, who farms sharecropped land, said: "I have no land of my own. I grew paddy on about one bigha and seventeen decimals of sharecropped land. About twenty days ago the disease suddenly appeared. I used pesticide, but I still cannot save the plants." Ujjal Mia, a farmer of Kochasahar village in Gobindaganj upazila, said: "We work hard all year to farm, but if the paddy is ruined by a disease like this, it will be hard to run our households. The government should act quickly."

The agriculture department gave a different account. Its officials told the newspaper that this was not a major disease: leaves were turning reddish because of a lack of needed rain and a shortage of plant nutrients, and because of faulty care by farmers it would take a little time for the leaves to turn green again. The report also cited experts who said that weather irregularities caused by climate change, excessive rain and swings in temperature were among the main reasons new paddy diseases spread, and who warned that without quick diagnosis and remedial action, aman production could be badly affected not only in Gaibandha but in neighbouring districts too.

Md Rostom Ali, additional deputy director of the DAE's Gaibandha office, said: "Field-level officers have collected samples of affected paddy from different areas. The preliminary assumption is that the plants are infected with bacterial leaf blight." He added: "The fields are waterlogged and unsuitable for paddy cultivation. Because nutrients were not applied to the transplanted aman seedlings, their growth is being hampered, and as a result the panicles or leaves are becoming diseased. Our field workers are keeping in regular contact with farmers about the disease."

According to the district DAE, aman had been planted that season on 1,33,125 hectares across the district's seven upazilas, and the production target had been set at 6,42,994 tonnes. The report did not give a figure for the area affected, and no laboratory result had been published by the date of the report.

Gaibandha is one of the five districts of the DAE's Rangpur agricultural region, with Rangpur, Kurigram, Lalmonirhat and Nilphamari. On 31 October 2025 the state news agency BSS reported that farmers in the region had cultivated aman on 6,21,505 hectares, 100.17 per cent of the targeted 6,20,430 hectares, and that the DAE had set a target of 20,10,505 tonnes of clean rice for the region. The agency said farmers had braved a drought-like situation during the first weeks of transplanting, and quoted the DAE's additional director for the region as saying that recent rainfall had helped the plants grow well and that short-duration varieties were giving high yields.

A week before the Gaibandha report, the Daily Observer reported on 12 November 2025 from Nageshwari upazila in neighbouring Kurigram district that bacterial leaf blight was spreading from field to field there. The upazila agriculture office had set a target of 24,360 hectares of transplanted aman and farmers had planted 24,365 hectares. The paper described yellow-green spots that later turned brown and dried out, a milky discharge from the leaves in dew or rain, and fields that from a distance looked ripe but on closer inspection held dried, damaged paddy. The senior upazila agriculture officer said leaflets were being distributed as part of an awareness campaign.

Gaibandha's farmers had faced a difficult aman season the year before as well. The Financial Express reported on 30 October 2024 that gusty wind and drizzle under the influence of cyclone Dana had flattened unripe aman plants in many fields of the district, where aman had been planted on about 133,000 hectares that season after drought and flood. A deputy director of the district DAE told the paper that farmers had been advised to tie up the flattened plants and to drain water from their fields.

The disease the DAE named as its preliminary assumption is one of the eight major rice diseases listed by the Bangladesh Rice Research Institute (BRRI). In the 25th edition of its farmers' handbook Adhunik Dhaner Chash (Modern Rice Cultivation), published in June 2025, BRRI says 32 rice diseases have been identified in Bangladesh, eight of them major. It calls bacterial blight a disease that can attack the plant at every stage. In seedlings it appears within 15 to 30 days of transplanting: the base of the plant rots, the leaves droop, turn yellowish and die, a condition called kresek, and pressing the base of an affected stem releases a sticky, foul-smelling ooze.

In older plants, BRRI says, leaf-blight symptoms usually show from the maximum tillering stage. The infection begins at the leaf tip and runs down along the edges. The bacteria enter through wounds in the leaf; the affected part first looks dry and water-marked, then turns yellowish and finally the colour of straw, and in time the whole leaf dies and dries. Excessive use of urea, hailstorms and stormy weather help the disease spread. In its quick diagnosis guide BRRI adds that drops of yellowish, cloudy liquid containing bacteria can sometimes be seen on the underside of affected leaves in the morning.

Banglapedia, the national encyclopaedia, records that the disease was first noticed in Bangladesh in 1966, that in transplanted rice it normally appears about six weeks after planting, that symptoms are often seen on the flag leaf, and that drying usually starts at the tip and extends down both sides of the leaf blade, sometimes reaching the leaf sheath depending on the variety.

The International Rice Research Institute (IRRI), in its Rice Knowledge Bank, names the cause as the bacterium Xanthomonas oryzae pv. oryzae. It says the disease favours temperatures of 25 to 34 degrees Celsius with relative humidity above 70 per cent, is common when strong winds and continuous heavy rain help the bacteria spread through ooze droplets, and can be severe in susceptible varieties under high nitrogen fertilisation. IRRI calls it one of the most serious diseases of rice: the earlier it occurs, the higher the yield loss, which can reach 70 per cent when susceptible varieties are grown in favourable conditions. Plants infected at the booting stage may not lose yield, but give poor-quality grain with a high share of broken kernels.

IRRI also describes a simple field test. A young lesion is cut across and placed in a clear glass of water; after a few minutes, held against the light, a thick or turbid liquid can be seen coming from the cut end if the cause is bacterial. Such signs can point towards the disease, but only a laboratory test of samples, like the one the Gaibandha office said it had begun, can confirm it.

Several rice problems can look alike in the field, which is why BRRI's handbook sets out how to tell them apart. Brown spot, a fungal disease, starts as small brown spots on the leaves with a light brown centre and often a yellow halo, BRRI says, and it can strike at any stage of the crop. IRRI's fact sheet gives its cause as the fungus Bipolaris oryzae and says it is common in unflooded and nutrient-deficient soils or soils that build up toxic substances, at relative humidity of 86 to 100 per cent and temperatures between 16 and 36 degrees Celsius. On average it causes a 5 per cent yield loss across lowland rice in South and Southeast Asia, and severely infected fields can lose as much as 45 per cent. IRRI notes that brown spot was considered the major factor behind the Great Bengal Famine of 1943, and Banglapedia says the disease is prevalent all over Bangladesh.

Tungro, which Banglapedia calls the most damaging viral disease of rice in Bangladesh, is spread by the green leafhopper. BRRI says leaves of scattered plants turn orange-yellow and infected plants stay shorter with fewer tillers. It adds a point that bears on the Gaibandha dispute: a shortage of sulphur or nitrogen, or cold, can also make rice yellowish, but not orange-yellow, and in that case the whole field turns yellow evenly rather than in scattered patches.

The DAE's other explanation, a shortage of nutrients, also has recognisable signs in BRRI's guidance. If rice stays yellow and grows poorly even after urea has been applied, a sulphur deficiency can be assumed. If plants are stunted here and there, the older leaves turn a rusty brown to orange colour and the plants have few tillers, a zinc deficiency can be assumed. In both cases BRRI's first step is to drain the water from the field before topdressing the missing nutrient at the recommended rate.

For bacterial blight, BRRI's handbook lists the following steps, none of which is a pesticide or fungicide:

• use fertiliser in balanced amounts;
• when the disease appears, topdress an extra 5 kg of potash fertiliser per bigha;
• stop topdressing urea for a while after storms and rain and after the disease appears;
• if kresek appears, dry out the affected field and irrigate again after 7 to 10 days;
• burn the stubble of an affected field after harvest.

IRRI says planting resistant varieties is the most efficient, reliable and cheapest way to control bacterial blight. Its other options are balanced nutrients, especially nitrogen; good drainage of conventionally flooded fields and nurseries; keeping fields clean by removing weed hosts and ploughing under stubble, straw, ratoons and volunteer seedlings; and letting fallow fields dry to suppress the bacteria in soil and plant remains.

For brown spot, BRRI advises applying organic manure and balanced fertiliser, and in the aman season arranging supplementary irrigation if the October rains stop. IRRI puts improving soil fertility first. On water in general, BRRI says rice fields do not need standing water all the time: shallow water for 10 to 12 days after transplanting helps new roots form, and after that less water will do as long as the plants do not suffer a shortage. In rain-fed transplanted aman areas, keeping field ridges 15 centimetres high and free of cracks holds rainwater, and its research found that supplementary irrigation in drought gave about one tonne more paddy per hectare than an unirrigated crop.

Because the cause in Gaibandha had not been confirmed by the date of the report, the safest course for a farmer with similar symptoms is to show the field to the sub-assistant agriculture officer or the upazila agriculture office, which can send samples for testing and advise on the right remedy and any chemical, if one is needed.

Gaibandha district, in Rangpur division, covers 2,114.77 square kilometres, according to Banglapedia. It is bounded by Kurigram and Rangpur districts to the north, Bogura to the south, Jamalpur, Kurigram and the Brahmaputra river to the east, and Joypurhat, Dinajpur and Rangpur to the west. Its main rivers are the Brahmaputra, Jamuna, Tista, Karatoya, Bangali and Ghaghat. Of its seven upazilas, Gaibandha Sadar, Gobindaganj, Palashbari, Fulchhari, Saghata, Sadullapur and Sundarganj, Gobindaganj is the largest and Palashbari the smallest.

The district's history is tied to its rivers. The area's former centre was Bhabaniganj, made a subdivision on 27 August 1858; its headquarters moved to Gaibandha in 1875 when Bhabaniganj was swallowed by the river through erosion. Gaibandha became a district in 1984. The 2011 census counted 2,379,255 people. Among the main sources of income, Banglapedia gives agriculture 65.08 per cent, followed by commerce at 11.85 per cent, and the district has an agricultural training institute among its educational institutions.

Rice is grown in Bangladesh in three seasons, aus, aman and boro. Banglapedia notes that transplanted aman is the most important of these crops and occupied about 46 per cent of the rice land in 2009-10, and that aman leads in area while boro leads in production. It records that the government's Food Department recommends 410 grams of rice per person per day, and that viral, bacterial, fungal and nematode diseases of rice are mostly prevalent between June and December, the months of the aman crop.

BRRI's 2025 handbook says Bangladesh ranks third among the world's rice-producing countries, with an average yield of 5.2 tonnes per hectare, against 6.5 to 7.0 tonnes in China, Japan and Korea; but those countries grow one rice crop a year, while in Bangladesh the same land can produce rice three times a year. The first high-yielding variety, IR8 from IRRI, was grown in farmers' fields in Bangladesh in 1968. BRRI varieties are now grown on about 80 per cent of the country's rice land and give about 90 per cent of its rice output, the handbook says.

For transplanted aman, BRRI recommends seedlings 20 to 30 days old, one healthy seedling per hill, rows 20 to 25 centimetres apart and 15 to 20 centimetres between plants. It describes a double-transplanting method for fields where waterlogging or another cause delays planting, known in the Rangpur area as bolan. The handbook also warns that climate change is raising the risk of drought, excessive rain, heat, cold, salinity and flash floods for rice, and describes a production management technology based on Bangladesh Meteorological Department forecasts that helps farmers act before such weather arrives.

BRRI itself was set up in 1970 at Joydebpur in Gazipur as an autonomous research organisation, according to Banglapedia, which lists Rangpur among its regional stations and Plant Pathology among its research divisions.

Photo: Ibrahim Husain Meraj / Wikimedia Commons (CC BY-SA 3.0)

Sources: Jagonews24, Bangladesh Rice Research Institute (Adhunik Dhaner Chash, 25th edition, June 2025), International Rice Research Institute Rice Knowledge Bank, Banglapedia, The Daily Observer, Bangladesh Sangbad Sangstha (BSS), The Financial Express