Rice longitudinal leaf borer is the main migratory and overeating pest in rice production in China, and is widely distributed in various rice production areas. The following sinking air currents and rainfall are driven by landing, moving from south to north in early summer every year, and moving back from north to south in autumn, recuring for many years, and the harm time is long, from the tillering stage of rice to the stage of pregnant ear-ear extraction.
Due to its larvae, the leaves of rice are curled, the tip of the bundle, and the leaf flesh is whitish, which affects photosynthesis, seriously affects the yield and quality of rice, causes the weight of 1,000 grains to decrease, and the grain rate increases, which can usually reduce rice yield by 10%-15%, and the weight can reach 50%.
Guangxi is the first stop for rice longitudinal leaf borers to migrate into China, and is also the source of insects in other rice areas. At present, the rice in Guangxi is in the jointing stage - pregnant ear stage, yesterday in the Laibin area of the field found, a large number of white leaves, bundle tips, peeling a look, almost every leaf has rice longitudinal leaf borer larvae. Today, I will briefly talk to you about which drugs have the best effect on rice longitudinal leaf borer, and put forward 2 auxiliary control measures.
There are a lot of white leaves and bunch tips in the field
<h1 class= "article-title" >, The effect of rice longitudinal leaf borer on rice yield formation</h1>
1. The formation of rice yield
More than 95% of the formation of rice yield is the result of the accumulation of leaf photosynthetic products. Of the resulting grain yields, 80% came from photosynthesis of functional leaves of rice at the panicle-maturation stage. Studies have shown that the contribution of rice leaves to yield is 52% of the sword leaves, 22% of the inverted two leaves, and 8% of the inverted three leaves. Therefore, the growth status of functional leaves of rice determines the yield of rice.
2. Hazard characteristics of rice longitudinal curl leaf borer
Rice longitudinal leaf borer is mainly a larvae that harm rice leaves, resulting in curly leaves and white leaves. In particular, the 4-5 year old larvae, eat large amounts, overeating leaves, frequent rotation of plants, leaf into longitudinal buds, hiding in them to eat the upper epidermis and leaf flesh, leaving only the white epidermis, the affected field, a white seedling, especially in the panicle stage - grouting stage, functional leaves are damaged, seriously affecting yield, resulting in yield reduction and harvest.
Rice longitudinal leaf borer larvae
3. Hazard characteristics of different insect ages of rice longitudinal leaf borer
According to the harmful characteristics of different insect ages on the leaves, it is summarized as follows: "The first-instar heart leaves now have needle-like white spots and rarely buds; the second-instar young leaves will be bundled with tips, spitting silk at the leaf tip or in the middle of the leaves to form small insect buds; the third-instar buds have longitudinal rolls, barrel-shaped, and openings at both ends; fourth- and fifth-instar larvae, with large food intake, binge eating leaves, causing damage to functional leaves, white leaves, twisting, gradually losing water and drying up." After five years of age, they become adults, and the average number of eggs laid by a single female is 100, up to a maximum of more than 300.
Rice longitudinal curl leaf borer adult
<h1 class="article-title" > second, effective control of rice longitudinal leaf borer, which agents have the best effect? </h1>
According to the harmful characteristics of different insect ages, we can know that in order to effectively control rice longitudinal leaf borer, it is best to seize the peak period of 1st and 2nd instar larvae before the third instar larvae. If the field has a large amount of adult worms, it is best to use the drug when the eggs hatch to the first instar larvae.
There are 150 rice bundle tips in the tillering stage, and more than 60 rice field tips in the 100 bushes of rice after the pregnant ear are reasonably combined with the combination of medicinal agents to carry out comprehensive control of diseases and insect pests. Generally, in the jointing stage, fracture stage and panicle stage of rice, three times of drug control.
The blades are longitudinally rolled and cylindrical
Recommend several chemical agents with good control effect on rice longitudinal leaf borer, and make reasonable choices according to the field insect infestation. It should be noted that this prevention effect is not absolute, and everyone uses alternately and reuses according to their own medication and field insect infestations to strive for the best control effect.
The efficacy of the agents is very good: 240g/L cyanidoniane hydrazone suspension agent 360 g / ha, 20% chloranthrine benzamide, the best control effect of the pest, 7-28 days after the drug, the control effect is as high as 92%;
The agents with better efficacy are: 60g/L ethyl polybactericide suspension agent 75 g/ha, 30% indinaria water dispersible granules 27 g/ha, 1.8% avermectin emulsion 60 g/ha, 1% methylamino avermectin benzoate microemulsion 30 g/ha, 20% fluorobenzamide water dispersible granules 45 g/ha and 40% chlorpyrifosensis thiamethoxen water dispersible granules 60 g/ha have a good control effect on rice longitudinal leaf borer, and the effectiveness period is 14-21 days. The prevention and treatment effect is as high as 88% within 7-28 days after the drug;
The general anti-drug agents are: 10% tetrachloroxamide suspension 60 g/ha and 6% avyl chlorobenzoyl suspension 3 g/ha, but the duration is up to 28 days, and the control effect is 72%-79% in 7-28 days after the drug;
Note: The situation of diseases and insect pests in the field is often more complicated, and for the treatment of rice longitudinal leaf borer and dimorphic borer, it is recommended to choose 60g/L ethyl polybactericide suspension 75 g/ha, 1.8% avermectin emulsion 60 g/ha, 20% fluorophenylfenamide water dispersible granules 45 g/ha, 40% chlorpyrifosensis and thiamethoxazine water dispersed granules. For another major pest, rice planthopper, 10% aqueous agent of alenophexate, 50% pyridone and isopropylvir wettable powder, 80% pyridoxine and thiamethoxine water dispersible granules, and 25% thiamethoxine water dispersible granules can be selected, and the efficacy is above 90%.
<h1 class="article-title" > summary</h1>
Rice longitudinal leaf borer is an explosive migratory flying pest, chemical control is still an important part of the comprehensive management of rice longitudinal leaf borer, in large years, it is best to mention the control period to the peak of egg incubation to improve the control effect and reduce losses. In addition, it is also possible to reduce the occurrence of insect pests with the help of scientific and reasonable fertilization. It mainly includes the following 2 points:
1. Control nitrogen fertilizer application and spray foliar fertilizer
In many rice production areas, farmers are often accustomed to increasing the practical amount of nitrogen fertilizer, resulting in excessive nitrogen fertilizer, resulting in thin leaves, scattered and long growth, improving the nutritional conditions of plant-eating insects, and high nitrogen is conducive to the growth, development and reproduction level of rice longitudinal leaf borer, including larval survival rate, feeding capacity, pupal weight, adult lifespan and egg production, and improving the population and hazard level of rice longitudinal leaf borer in the rice field.
In Yuyao and Linhai- related experiments in Zhejiang Province, it was shown that after the nitrogen fertilizer application rate of Zhejiang Japonica 88 and Yongyou 18 was reduced by 27% and 13%, the population of rice longitudinal leaf borer larvae in the field was reduced, and the agricultural non-point source pollution was reduced, and the yield was increased by 10% and 13%, respectively.
If the nitrogen fertilizer is applied in the early stage and the field is shady, 100-200 grams of potassium dihydrogen phosphate can be added to the drug control and control to promote the old maturity of the sword leaf. With the old sword leaves, it is not suitable for the leaf curling and feeding of rice longitudinal leaf borer larvae, which is a key measure to control rice curly leaf borer.
2. Apply silicon fertilizer
A significant feature of rice-resistant longitudinal leaf borer rice varieties is that the leaf silicon content is high or the silicon cell density is high, and silicon application can enhance the non-selectivity of rice longitudinal leaf borer to rice, thereby enhancing the resistance of rice to rice longitudinal leaf borer, and significantly reducing the leaf curl plant rate and leaf curl rate of rice.
This may be because the application of silicon fertilizer can increase the silicon content of plants, improve the leaf roughness of grasses, hinder leaf-eating insects, delay development, and reduce food assimilation efficiency; at the same time, promote the synthesis and release of volatile secondary biomass of plants, and thus affect the spawning and feeding choices of plant-eating insects.