Farmers in Central Thailand Remain Trapped by the BPH Problem

by
M. M. Escalada,  Visayas State University, Leyte, Philippines
Patchanee Chaiyawat,  Phranakorn Sri Ayuttaya Rice Research Center

In mid-August 2010, we traveled more than 1,500 km through the central region, stopping in Nakhon Nayok, Uthai Thani, Chainat, Ang Thong, Phitsanulok, Phichit and Ayuthaya provinces talking to farmers about their rice crop and the changes they have made to their cultural management to deal with the BPH problem and to explore their attitudes toward ecological engineering.

In mid-August 2010, we traveled more than 1,500 km through the central region, stopping in Nakhon Nayok, Uthai Thani, Chainat, Ang Thong, Phitsanulok, Phichit and Ayuthaya provinces talking to farmers about their rice crop and the changes they have made to their cultural management to deal with the BPH problem and to explore their attitudes toward ecological engineering.

Uthai Thani

Last season, some farmers in Uthai Thani had grassy stunt virus which wiped out their rice crop. Those who planted Supan Buri 60 experienced BPH outbreak which pushed them to shift to RD31. In last year’s outbreak, some farmers lost as much as 60,000 – 70,000 baht for which they paid 7.5% interest to the Bank of Agriculture and Agricultural Cooperatives (BAAC).

Among those farmers was Wanna Thongma, 35, who has been farming for 10 years in Uthai Thani province. During last year’s BPH outbreak, she lost 4 tons from her 2.92 ha planted to Suphan Buri 3. She applied insecticides 12 times but could not remember the product names of the chemicals distributed free by the province, as part of the government’s response to the BPH outbreak. She said they sprayed every 10 days and the BPH persisted and they would follow it up with another spray after 4 days. She admitted that the 12 insecticide applications did not help solve her BPH problem.  Although they also consumed the rice they planted, farmers in the area did not seem to worry about pesticide residue. Wanna thought that the BPH outbreak was caused by higher temperature. She recalled an outbreak many years back which they quickly solved with 1-2 sprays.

Her production cost for her entire rice farm was THB 30,000 (US$ 968) but she lost a net amount of THB20,000 (US$645). She said another woman farmer spent THB 70,000 to operate a 27-rai (4.32 ha) rice farm but lost more than THB 50,000 (US$1,612).

Her neighbor, Saangsri Samransuk, has been into rice farming for  the past 20 years, tilling a total of 36 rai (5.76 ha), 9 rai of which is rented at THB 1,500/rai/year or a total yearly rent of THB 13,500 (US$435). She planted RD31 this cropping season but she believes that planting RD31 is not sufficient to avoid BPH attack.

Rice millers in Uthai Thani give the same price to Pathum Thani 1 and RD 31 if the truck is not full. If the truck is full, they give a higher price for Pathum Thani 1. Suphan Buri 3 sells at a price range of THB6,000 to 6,600/ton.

It was the local extension technician, who advised both women farmers to apply insecticides to control BPH. They were trained and received free insecticides from the government and also bought the same type of insecticides from the shop. The pesticide seller also recommended particular insecticides. To control BPH this season, they plan to flood the field to submerge the BPH eggs. They came up with this idea themselves and will explore if it works.

This season, both Wanna and Saangsri have already applied 3 insecticide applications – first at 40 days after transplanting with cypermethrin to kill the worms, the second was buprofezin for leaffolders, and the third was also buprofezin for BPH.  They thought that without spraying insecticides the rice crop will have stunted growth, it will turn yellow and they will have nothing to harvest.

Several years ago, both women farmers attended the IPM farmer field school where they were taught pests, predators, bio-extracts, the right chemical to use for BPH, not growing rice successively and reduce the seed rate to 94 kg/ha However, when they applied bio-extracts in their field, they found these to be useless as the planthoppers from other fields migrated to their fields. Bio-extracts, they said, could not compete with chemicals.

Phitsanulok

A village leader in Wangpikun, Wang Thong district, Napasin Khonsangaim, 37, has been cultivating a 16 ha-rice farm for 15 years. Farmers in the area practice staggered planting with irrigation water drawn from natural sources for which they pay the local government the cost of electricity to pump the water. In the dry season, the cost is $40.32/ha and $30.24/ha during the rainy season.

Napasin recalled that the BPH outbreak last year was severe and realized that spraying did not solve the problem. He lost only 20% of his rice crop because he had planted Phitsanulok 2, a resistant variety. Where he used to harvest 5.31 t/ha or a total of 85 tons in a normal cropping season, he only managed to generate 70 tons from his 16 ha.

Another farmer, Sirm Rienchay, 65, who operated a 4.96 ha rice farm, had planted Chainat 1 rice variety and lost nearly 70% of his expected production.  Before the outbreak, he used to harvest up to 27 tons, but during the outbreak, he yielded only 9 tons. He said that farmers in their village liked to plant Chainat 1 because it has better grain quality. Chainat 1 fetched a price of THB7,300/ton while Phitsanulok 2 was sold at THB6,900/ton.

When the BPH outbreak struck, both farmers applied insecticides 5 times, using chemicals recommended by pesticide sales agents and sellers and other farmers who had used them before and found them to be effective. The first spray was cypermethrin to control thrips; second, were abamectin and chlorpyrifos for stem borers and case worms; third, buprofezin for BPH; fourth and fifth were dinotefuran for BPH.

Napasin believed that the BPH outbreak was caused by continuous rice planting while Khun Sirm thought it had to do with the cooler temperature brought on by the rainy season. Both acknowledged that the amount of yield loss depended on the rice variety they planted. Chainat 1 suffered 30% loss. Other farmers, they noted, had also lost heavily because the sprayed at the wrong time and might have used the wrong insecticide.

Both farmers recalled that about 3 years ago, a BPH outbreak occurred twice. They found that only those areas planted to Chainat 1 were damaged while those with Suphan Buri 1, Suphan Buri 2 and Phitsanulok 2 were not affected by the outbreak. Last cropping season, to solve his grassy stunt virus problem, Khun Sirm applied both organic and inorganic fertilizers but it did not help. He lost his 1-6-ha rice crop. Napasin observed that grassy stunt virus occurs when the soil texture is sandy clay which characterizes the soil in Phitsanulok province. It is prone, he said, to sheath blight and dirty panicle disease.

To avoid an outbreak this season, Khun Sirm shifted to planting Phitsanulok 2 and both farmers reduced their insecticide use frequency to 2 to 4. They are optimistic that there will be no outbreak this season. Napasan pointed out that a BPH outbreak usually occurs at the early crop stage (20 DAS) but their current rice crop is already at the last growth stage and there has been no BPH attack yet.

Napasin and Khun Sirm are seed producers for the Phitsanulok Rice Seed Center. As seed producers, they must make sure that there are no mixtures and no weed contaminants in their rice seeds.

Phichit

In Bangphai village, Bangmulnak district, Wanna Chumpunute, 54, has been managing a 4.48 ha-rice farm for 35 years. She used to grow Chainat 1 but had to shift to Tathum 80 (RD31), a rice variety recommended by the Phitsanulok Rice Research Center. Using the parachute transplanting method, Wanna would usually harvest 23 tons. However, during the BPH outbreak last year, she got only 5 tons, representing almost 80%  crop loss. For this loss, the government gave farmers 1,000 ml isoprocarb for every 10 rai (1.6 ha). She said the farmers’ bank, BAAC, helped farmers by allowing them to delay their loan payments for a year without interest.

Panida Copachan, 32, has been farming for 18 years using a transplanting machine to establish her rice crop. She used to plant Chainat 1 but has now shifted to RD31, a government-recommended resistant variety. Panida used to harvest 23 tons from her 4 hectare farm but when the BPH outbreak struck, she got only 15 tons. She believed that her yield loss was not substantial because transplanting made it easier for her to manage the planthoppers.

During the BPH outbreak, Panida sprayed 5 times, mostly dinotefuran and buprofezin to control the BPH. On the other hand, Wanna applied insecticides as many as 7 times. Her first application was abamectin and she could not recall the names of the 6 other insecticides her husband applied. To choose the chemicals to apply, they checked the leaflet that they had obtained from training, consulted the Phitsanulok Rice Research Center staff, and asked other farmers in their farmer group. Although they had attended the IPM farmer field school, they kept on spraying insecticides but they realized that excessive insecticide use could not get rid of the planthoppers.

To prevent another outbreak, they selected a resistant variety but they soon realized that with continuous planting, they needed to keep on changing their rice variety. According to them, a resistant variety is one that requires good cultural management and is easier to manage than a susceptible one.

A BPH outbreak had occurred 10 years ago but both farmers recalled that after that outbreak, the planthoppers disappeared. This time, the outbreak was followed by grassy stunt virus and ragged stunt virus. The agriculture officials had told her that the BPH outbreak is caused by continuous rice growing which did not cut the planthoppers’ life cycle.  Wanna believes that a farmer cannot grow rice without using insecticides because other farmers also use insecticides. She expressed disbelief that planting nectar-rich flowers on the bunds can help farmers reduce their insecticide use. She explained that natural enemies can seek refuge in the flowers and vegetables on the bunds but the planthopper will go directly to the paddy and eat all their rice.

Tagged as: BPH problem in Central Thailand