“Now the purchase price of long beans is 8.3 yuan per catty. I can pick more than 3000 catties today.” At about 10:00 on March 2, farmer Yang Qinliang opened an agricultural vehicle to pick the 11th crop of long beans in Tiantou, angwai village, Da’an Town, Ledong Li Autonomous County. “The long beans planted by other farmers enter the final stage after picking 10 stubbles, while the long beans planted by me are still in the high-yield period, and the appearance is very good, because I have applied green technology.” When Yang Qinliang said “green technology”, the volume increased significantly.

Insect repellent lamp hanging in Litchi forest in Nandao village. Photographed by Li Tianping, reporter of Hainan Daily

“Green technology” mentioned by Yang Qinliang is green pest control technology, mainly including physical control technology, biological control technology, ecological regulation technology, etc. This kind of technology is green and environmental protection, which can be called the “new thirty-six measures” for insect control.

Take a drastic measure

Use organic fertilizer to prevent insects from the source

Long bean is one of the main varieties of melons and vegetables in Hainan in winter. Ledong planted 40000 mu of long bean last winter and this spring. In early March, long beans planted with traditional methods entered the late picking period, while long beans planted with green pest control technology are still “fruitful”.

A farmer in Chengmai bagged apple dates to prevent insects. Photographed by Hainan Daily Reporter Yuan Chen

Yang Qinliang planted 20 mu of long beans. At a glance, the green leaves are covered with slender long beans. Every few steps, you can see a yellow board or blue board hanging on the support (i.e. insect luring color board). The fields are crisscrossed with thick or thin plastic pipes, and the soil is very soft. Dozens of peasant women are wearing sun visors picking long beans.

“The light and heat conditions in Hainan are very good. Crops can be planted in all seasons, but this has both advantages and disadvantages. Due to the lack of rest of the land and the long-term use of chemical fertilizer, the soil acidification and hardening, the soil fertility continues to decline and the incidence of diseases and pests is high.” Zhang long, a technician at Ledong Agricultural Technology Center, explained that the yield of long beans planted by traditional methods is about 2000 kg per mu. After 10 stubbles, the plants begin to age. Over the past few years, Ledong has vigorously promoted green agricultural technology. Yang Qinliang “dared to eat crabs”, planted long beans with organic fertilizer and tasted the sweetness.

“When preparing for farming, I applied 1000 kg of organic fertilizer per mu to improve the soil structure.” Yang Qinliang said that the short-term effect of chemical fertilizer (compound fertilizer, the same below) is good, and the incidence of diseases and pests is high after the fertilizer is exhausted, while organic fertilizer can continue to exert its power and prolong the picking period of long beans without “side effects”.

Yang Qinliang’s insect luring color board hanging in the bean field. Photographed by Zhou Yueyue, reporter of Hainan Daily

During the growth period of long beans, Yang Qinliang also applies chemical fertilizer, but he uses the integrated facilities of water and fertilizer. In one corner of the field, the reporter of Hainan Daily saw that a thick plastic pipe was connected to a large bucket. There were a pump at both ends of the bucket. One pumped up the water in the nearby ditch and the other pumped up the water and fertilizer mixed with chemical fertilizer, and then transported the water and fertilizer to the root of each bean through the pipe network. Yang Qinliang said that the transportation of water and fertilizer in this way can save fertilizer and water, and can also reduce a lot of labor costs.

“The main component of chemical fertilizer is nitrogen, phosphorus and potassium. Organic fertilizer is rich in trace elements. Using only chemical fertilizer is equivalent to people eating only rice, which is prone to malnutrition; using organic fertilizer and chemical fertilizer together is equivalent to people eating not only rice, but also meat, eggs and milk, which has complete nutrients.” Zhang Long said that if the human body has sufficient nutrition, the immunity will naturally be improved, and the ability of plants with complete nutrients to resist diseases and pests will be enhanced. The improved variety of Yangqin has few diseases and insect pests, long picking period, and the yield per mu can reach 5000 kg. The reduction of the use of organic fertilizer and chemical fertilizer is an important reason.

the tactic of luring the enemy away from his base

Trapping and killing pests with yellow and blue color plates

Pest control is the key to planting long beans. Long beans are prone to four kinds of diseases and pests: rust, Fusarium wilt, thrips and Liriomyza sativae. Applying organic fertilizer in the field can effectively reduce the risk of “rust” and Fusarium Wilt of long bean.

Flat bellied wasp release card. Photographed by Li Tianping, reporter of Hainan Daily

Zhang Long said that thrips and Liriomyza sativae, two pests, do great harm to long beans. Thrips parasitize in the flower buds of long beans, which directly affects the quality of long beans. When the situation is serious, it will also lead to flower loss and greatly reduce the yield of long beans. The larvae of Liriomyza maculatus sneak into the leaves of long beans to feed, resulting in irregular insect paths in the leaves, hindering the photosynthesis of the leaves and affecting the growth of long beans.

In the past, farmers mainly used chemical pesticides to control thrips and Liriomyza sativae. Although the effect was good, it damaged the quality of long beans and had potential food safety hazards. In recent years, agricultural departments at all levels in Hainan have vigorously promoted green pest control technology and guided farmers to use insect trapping color plates to kill thrips and Liriomyza sativae.

Thrips prefer blue, and Liriomyza sativae prefers yellow. According to the color preference of these two pests, pest control experts designed blue and yellow boards with mucus.

“The validity period of blue board and yellow board is relatively long, generally more than 20 days, and the insect control effect is also good. It can not only kill thrips and Liriomyza sativae, but also monitor the population density in the field.” Zhang Long said that in agricultural production, the comprehensive use of pesticides and insect luring color plates has the best effect on pest control. If farmers standardize the use of insect luring color plates, the number of pesticide spraying can be reduced.

Zhang Long said that the insect luring color boards promoted by Ledong are biodegradable biological products. This year, the county plans to promote the use of green pest control technology in long bean planting areas of more than 5000 mu, and distribute more than 100000 insect luring color boards.

Killing insects with a knife

Introduction of nemesis to eliminate litchi stink bug

In early March, the litchi forest in Nandao village, Yongxing Town, Xiuying District, Haikou City ushered in the flowering period, and the light yellow flowers of each tree gave birth to the hope of a bumper harvest. Flower is the “delivery room” of fruit. Therefore, pest management during flowering is very important for litchi growers.

There are lamps hanging in the litchi forest. From a distance, they are somewhat similar to the street lamps next to the urban green belt. A staff member said that this is a kind of lamp to trap and kill pests, which is mainly used to kill stem borers.

A flat bellied wasp release card is also hung on the treetops of some litchi trees. The main function of this small card is to inhibit the growth of litchi stink bug. Flat bellied wasp is a species that parasitizes in secondary eggs. Its adults often move among litchi trees, look for litchi secondary eggs to parasitize and lay eggs in secondary eggs. After the egg of the flat bellied wasp becomes a larva, it will suck the secondary egg liquid, prevent the further development of the secondary egg and reduce the number of litchi secondary.

In recent years, Haikou has built a “CD-ROM” green prevention and control system and water protection system in many litchi planting bases