With the severe cyclonic storm "Amphan" approaching the coast, the agricultural office has advised farmers in coastal districts to harvest all the paddy that have matured up to at least 80 percent matured.

The advisory said there was a possibility of a storm with light to heavy rainfall from May 19 to May 21 in 25 districts, mainly on the coastal belt.

"The stormy weather and heavy rainfall may affect standing crops," said the Department of Agricultural Extension (DAE) in its advice issued yesterday by its Agro-Meteorological Information Systems Development Project.

The cautionary warning comes as farmers have harvested 59 percent of Boro paddy cultivated on 47.54 lakh hectares this season. And the DAE said the coastal divisions -- Chattogram, Khulna and Barishal -- account for 10 percent of the total acreage of Boro, the main crop that has roughly 55 percent share in the annual rice production estimated at 3.64 crore tonnes in 2018-19.

"We are requesting farmers through loudspeakers to harvest crops with 80 percent maturity quickly. We have also asked them to use reapers and combine harvesters to do it as quickly as possible," said DAE Director of Field Services Wing Alhaz Uddin Ahmed.

The DAE said farmers already harvested 86 percent of the Boro crop in the southeast division of Chattogram and southwest division of Khulna. The southern coastal division of Barishal saw a harvest of 62 percent of the Boro paddy grown on 1,25,000 hectares, according to Alhaz.

"We expect that maximum crop would be harvested before the cyclone hits," he said.

Agronomists said it is not clear how much crop might get damaged by the cyclone, which may cross the coastal belt in the early hours of Wednesday (May 20).

Mirza Hasanuzzman, professor of the Department of Agronomy at Sher-e-Bangla Agricultural University, said as high yielding varieties of paddy are of lower heights, there was possibility of inundation damaging the crops.

"If the cyclone hits, it may cause a major loss of paddy, which mostly may be 20-30 percent of the standing crop yield," he said.

Md Shahjahan Kabir, director general of Bangladesh Rice Research Institute said the ratio of the immature paddy on the field is insignificant. There may be immature paddy in Rangpur, the northwest division.

The extent of the damage would be high had the crop been half-ripen, he said.

Kabir said if the cyclone hits the southwest coastal district of Sathkhira, the loss would not be too major.

"I hope farmers would be able to harvest their crop anyhow," he said.

Mazharul Aziz, project director of Agro-Meteorological Information Systems Development Project at the DAE, said, until now, the forecast says there might be heavy rainfall and wind.

"But a cyclone is ever-changing. So, what the effects might be is not clear yet. We will update our advisory again tomorrow [today]," he added.

In its advisory, the DAE also suggested farmers harvest mature vegetable and fruits, and refrain from using pesticides. It also recommended using nets surrounding ponds to protect fish from washing away during heavy rainfall.

In the Barishal division, around 62 percent of the paddy on these lands have already been harvested, said Toufiqul Alam, deputy director of Barishal region DAE.

Of the rest, Boro paddies on around 26 percent of lands are scheduled to be harvested within tomorrow (Tuesday), and the rest 12 percent paddies are yet to ripen, he added.

"If the cyclone hits this region, this 12 percent of paddy will be damaged. The amount of these 12 percent can be estimated to 50,000 metric tons of paddy," he added.

"Now we are working hard to quicken the harvesting of the already ripened paddy. We are requesting teachers and students of different educational institutions to help with harvesting," he added.

Humayun Kabir, a farmer of Burikhali village in Pirojpur's Nazirpur upazila said, "Most farmers in our village, including me, have completed harvesting. Some 10 percent of paddy remains to be harvested. We hope that the rest is harvested in a day or two."

Contacted, Divisional Commissioner Muhammad Yamin Chowdhury said, "We have already directed DAE officials to take necessary measures to harvest ripe paddy as soon as possible. But we cannot harvest green paddy. We are trying our best to save the maximum amount of paddy."

In the Khulna division, around 86 percent of Boro paddy has already been harvested, according to DAE officials.

Boro paddy is cultivated in Khulna, Bagerhat, Satkhira and Narail districts in the division. Boro paddy was cultivated on over 2.43 lakh hectares of land. Of these, paddy on some 2 lakh hectares have already been harvested, said Kazi Abdul Mannan, additional director of Khulna region DAE.

"We have asked all the farmers to complete harvesting within the shortest possible time," he added.

Speaking to The Daily Star, some farmers said they were working hard to complete the harvesting.

"I cultivated Boro paddies in 7 Bighas of land. I have already harvested the paddy on around 5.5 Bighas of land. I have been working hard to complete the harvesting on the rest 1.5 Bighas of land," said Alamgir Hossain, a farmer of Noihati village in Khulna's Rupsha upazila.

In the Chattogram region, 86 percent of Boro paddy has been harvested, according to DAE officials.

Boro paddy was cultivated on 2.30 lakhs hectares of land in Chattogram, Cox's Bazar, Noakhali, Feni and Laxmipur districts.

Of these, paddies on some 2 lakhs hectares have already been harvested, said Md Nasir Uddin, deputy director of DAE Chattogram office.

"On loudspeakers, we urged the farmers to harvest the remaining paddy with two or three days," he told The Daily Star.

(Our Correspondents from Barishal, Pirojpur, Patuakhali, Khulna, Bagerhat, Chattogram and Noakhali contributed to this report.)