By Uma Partap and Tej Partap, ICIMOD, Nepal
In Maoxian County apples planted on a large-scale in the 1980s are now an important cash crop. Dr Uma Partap explains, \"Pollination problems started right at the beginning. There is a very low proportion of polliniser trees and a scarcity of pollinating insects because of pesticides\".
Maoxian County is in Aba Prefecture in Sichuan Province, South China. Apple cultivation started in 1935 with the planting of 30 trees of six different varieties. Large-scale cultivation started in the early I 980s, when apple became a main cash crop of the County. Apples from this region are known as \'Moawen Apples\' and are famous for their quality. They are sold in markets in Beijing, Tianjing, Guangzhu and Hong Kong, and also are exported to Russia and south-east Asian countries.
In Maoxian County there are 2,830 hectares of apple trees producing around 30,000 tonnes of apple, worth 33.9 million Yuans (US$ 4.2 million) every year. However in recent years, apple production has dropped in both yield and quality. We therefore investigated whether the pollination of the apples was adequate.
We prepared a questionnaire, surveyed the apple area, and interviewed farmers. Because apple is the main cash crop, farmers aim for maximum yield and quality by using every possible orchard management technique like irrigation, fertilisers, pruning, and use of pesticides and fungicides. Field investigation revealed that almost every apple flower is pollinated by hand instead of by insects like honeybees.
Pollinating apples by hand Pollination of apple flowers by hand is very common in Maoxian County despite the fact that beekeeping is popular in the area. The following issues emerged:
Pollination by hand
Pollinating apples by hand is a community effort. Apple flowering begins at lower altitudes and progresses upwards. Thus all apple farmers in the higher areas of the County are free of work and are hired to pollinate apples in lower areas. Since orchards are very small, larger families are able to pollinate their whole crop by themselves.
In hand pollination the anthers are picked from a flower of the polliniser variety when the flower is at the balloon stage (partially open flowers) and is dried to release pollen grains. Farmers usually dry the anthers by spreading them out in the sun for a day or two. Some use cardboard boxes provided with an electric bulb, and others even use electric blankets to dry the anthers. The pollen grains are stored in a cool, dry place and remain viable for three to four days. These are mixed with a little white flour or skimmed milk powder and are applied to the flowers of the main variety (within two days after a flower opens) with the help of a hand made brush, the filter side of a cigarette, or a pencil rubber. The farmers pollinate three out of the five flowers in an each apple inflorescence. Hand pollination is carried out three times in each season to ensure pollination of late flowers.
Economics of pollinating flowers by hand
Pollinating flowers by hand is very laborious and time consuming. About 20-25 people are needed to pollinate apples in one orchard in one day. The fee for one person is about 20Yuans per day, and this means that farmers pay about 600 Yuans (US$ 70) for pollination of their apples. Farmers could hire less labour, as apples bloom for about a week, but they want to rush in case of adverse weather conditions.
Economics of bee pollination
A maximum of two colonies of honeybees are needed to pollinate an apple orchard. The rental fee for one honeybee colony is US$7, which means that farmers would pay only US$14 to pollinate their orchards using honeybees. This calculation shows that bee pollination would be five times cheaper, but the farmers are still using hand pollination for the reasons described above.
Role of Government
A farmer, Li Jicai of Jingzhao Village, was the first to start pollination by hand. The County Government then took over and with its extension services spread the technology of hand pollination. Field experiments to standardise the technique were completed by 1990, after which farmers were given training in 1991. At that time only some farmers accepted the technique. But as the impact of pollination by hand became apparent other farmers in the County were also convinced. In 1994, 1,300 hectares of apples were pollinated by hand, and by 1997 the whole 2,000 hectares of apples were pollinated this way.
We are grateful to Dr He Yonghua and Xie Jiasuei for accompanying us to the field sites and assisting with interviewing farmers. Also to our Chinese colleague in ICIMOD,Dr Tang Ya who helped co-ordinate our study. Our special thanks go to the mountain farmers of Maoxian County for sparing time from their already busy schedule to provide us with valuable information.
[Bees for Development Jounal #54]