Rice seed treatment and pest prevention
The three main diseases of rice are: rice blast, bacterial blight, and sheath blight. Other important diseases are rice smut, bastard disease, trunk disease, downy mildew and so on. The root causes of disease outbreaks are: the increase in the proportion of high-quality susceptible varieties, the increase in the number of physiological races of pathogens, and the change in the farming cultivation system are in favor of the development of diseases and hazards.
There are many pathogenic bacteria on rice seeds, which can show various disease symptoms at different stages and stages of rice growth. Bacillus disease, trunk disease transmitted by seeds. Bakanae disease is mainly caused by seed wintering, seed germination, infecting the stem base of diseased seedlings, and spread by soil infestations such as sheath blight, rice blast, and bacterial blight. Among them, Rhizoctonia solani occurred in the largest area with the highest incidence rate, and the yield reduction rate in the damaged fields was up to 50%. The sclerotia were mainly transmitted to the soil in the winter. After the occurrence of a species-borne disease, the growth, development, yield, and quality of the rice plant have various degrees of influence. Second, because rice strains carry disease (disease), it is the primary (primary) source of infestation of the rice plant. Seasons can cause re-infestation, occurrence, spread, and damage of disease. Traditionally, for the prevention and control of disease transmission, at the current stage, we have used seed treatment before sowing to eliminate the disease and prevent seed and seedlings from being harmed by soil-borne diseases and pests. Bactericides used for seed treatment Seeds are treated in a variety of types, including inorganic and organic, volatile or non-volatile, systemic or non-systemic. Formulated as a powder, a water-soluble powder, a wettable powder, an emulsion, a liquid or a suspension. A good seed treatment should not leave any harmful residues that affect seed germination, seedling development, plant growth, and product.
Since the 1950s, China began to use pesticides to soak seed and seed dressing to control underground pests and seedling diseases. Since the 1980s, rice seeds have been coated to facilitate the absorption of nitrogen in soil and fertilizer by rice seeds and prevent and treat plant diseases and insect pests at the seedling stage. Numerous investigations and tests have shown that rice seeds that have been soaked, seed-dressed or coated with pesticides can prevent or reduce seed rot, seedling blight, damping-off, and other diseases caused by seed and soil-borne pathogens. Losses increase production and save a lot of manpower, material resources, rice seed use and time.
The following describes the methods of rice seed treatment, the main pesticides used, and their disease prevention and control.
1 seed dressing
1.1 40% suspension concentrate of Weifu (active ingredient: Wei Ling Ling, Fu Mei Shuang) developed by Ulead Chemical Industry Co., Ltd. of the United States, mainly used for controlling rice blight (160-200 g/hm2) and bastard disease (120 ~ 160g/hm2).
1.2 Rhizomatide (active ingredient: fipronil) 5% seed dressing agent developed by Rhône Planck of France, mainly used for rice planthoppers, rice leaf roller, rice blast horse, rice blast mosquito ( 80-160g/100kg seeds, mixed rice: 20-40g/kg, conventional rice).
1.3 Good Years and Winters Developed by U.S. Fumeishi Company (Active ingredient: Carbofuran, 35% Seed Treatment Agent, used to control rice thrips (210-400g/100kg seeds), Rice gall midge (600-800g/ 100kg seeds).
The above three kinds of foreign seed treatment agent varieties, although registered in China, but its high price, it is difficult to promote a large area in the country.
1.4 The Chinese patent (CN1064588) proposes a multi-fuction fungicide (10 to 50% of its active ingredient, carbendazim, and 50% to 10% of Fumei Double), which is mainly used for the control of rice blast and spotted bursa (50g/100kg). ).
1.5 High-efficiency, broad-spectrum composite bactericide developed by Liaoning Provincial Academy of Agricultural Sciences Plant Protection Institute Rice Disease Research Institute, "Bacterial disease clearing" (40% wettable powder 50g/10 ~ 13kg seeds), mainly used for the prevention and treatment of seedling disease, Rice bakan disease, blight, bacterial wilt, and damping-off disease have special effects, and at the same time, they have root-strengthening and anti-cold effects.
The two kinds of seed treatment agents mentioned above all contain carbendazim components. It has now been found that bastard diseases, etc., have produced resistance to carbendazim. Therefore, carbendazim and its compound formulations have been applied in areas where there are drug-resistant strains. The control effect has dropped significantly.
1.6 Imidacloprid seed dressing had no adverse effects on the germination and emergence of rice seeds. It had a high insecticidal activity against rice blast horses and had a long duration of efficacy. The leaf rolling rate control efficacy was still above 95% for 46 days after sowing. In addition, it has a positive effect on the improvement of the quality of seedlings, which is the direct effect of stimulating growth. It also needs to further study the effects of controlling the occurrence and harm of rice thrips and indirectly improving the quality of seedlings.
2 Soaking
2.1 China Patent (CN97100851) proposed TCCA (trichloroisocyanuric acid) as a disinfectant. First dry powder is used as a seed for 0.2% of the seed dressing and then stored. Before sowing, it is soaked with TCCA 500-300 times for 12-36 hours. The germination rate of 144 to 166 days of powdered seed dressing treatment was 6% to 12% higher than that of the control. Field investigation showed that the control effect against bacterial streak, cotton rot, rice blast, bakanae disease, and sheath blight was achieved. 88% to 100%.
2.2 Chinese Patent (CN1096158) proposes a rice seed disinfectant (in which the active ingredient is 4-(2,2-dichloro-1,3-benzodioxol-4-yl)pyrrole-3-carbonitrile and 5- Ethyl-yl-5,8-dihydro-8-oxo[1,3]dioxolyl-[4,5-g]quinoline-7-carboxylic acid) at very low concentrations (7.9 ga.i./1000 kg seed) has a very high control effect against rice bakanae disease, rice blast disease, and leaf spot disease.
2.3 The imidazolium seed germicide rice blast ester developed jointly by Japan Ube Industries Co., Ltd. and Japan's Beixing Chemical Industry Co., Ltd. is effective against bakanae, rice blast, and leaf spot of flax (200 times liquid, control rate 98). %the above). Although the combination of benzimidazole and thiram has been widely used for the prevention and control of the above diseases in a large area, the long-term use has led to the emergence of a benzimidazole strain of F. moniliforme, resulting in benzimidazole fungicides against rice seedlings. The activity of the disease is reduced. However, rice bran ester is effective against benzimidazole fungicides. In addition, in the incubation test of the nursery box, it has also shown that the rice seedling blight caused by soil-borne pathogens such as Trichoderma viride and Fusarium is well controlled.
In addition, Germany's 25% Shi Bao Ke (Mi Sun) EC 62.5 ~ 125mg/kg soaking), bacteria and insect clear (400 times liquid soaking), etc. also have a certain effect on the control of rice Bakanae disease. The bacterial and insecticidal cleansing (400-fold solution soaking) developed by the Institute of Agricultural Science and Technology in Zhenjiang, Jiangsu Province is used to treat stem nematode disease, which can cure bakanae disease and rice blast disease, and can overcome the resistance of bacillus against carbendazim produced by Bacillus subtilis in some areas. And the stability of governance.
3 seed coating
3.1 film coating
3.1.1 Chinese Patent (CN86100095) No. 11 Seed Coating Agent (Active Ingredient: 7% Carbofuran, 5% Carbendazim, 5% Formamide, and 5% chlorhexone): No. 12 Seed Coating Agent (Active Ingredient: 5) Carbofuran, 7.5% carbendazim, and 7.5% methyl zinc arsenate all control rice seedlings and early stage pests and diseases. No. 15 seed coating agent (active ingredient: 3% carbofuran, 6% carbendazim, 3% chlorpyrifos, and 6% enemy pine) to prevent bastard disease, cotton rot, etc., concurrent treatment of leafhoppers, planthoppers, aphids, underground Insect pests and disease deficiencies, drug ratios are 1:70 to 80.
3.1.2 20% rice seed coating agent produced by Zhangzhou Seed Coatings Factory (active ingredient: 10% carbofuran, 5% methyl-isofluosaphos, and 5% carbendazim) comprehensively control the underground pests, bakanae, and roots of rice Rot disease, dry nematode disease, bird and mouse damage, prevention of continuous cropping disorders, and deficiency of the disease. The proportion of drug species is 1:70-80.
Although several kinds of seed coating products in the above products have many functions, their products are highly toxic, and there are safety problems in the process of storage and application.
3.2 Pelletizing
3.2.1 Te Gongzuo (55-22045) proposes to use calcium peroxide seed coat powder (25% calcium peroxide, 25% plaster, and the rest calcium carbonate) to cover the rice species that began to germinate, and then insert it into shallow-water soil. Among them, the slow release of oxygen by calcium peroxide in water can promote rooting, germination, and emergence of rice seeds, making the initial success of rice cultivation. However, the seedling rate of rice coated with this kind of powder coating is still about 75%. And the effect is unstable.
3.2.2 Atomic energy research of Jilin Academy of Agricultural Sciences So calcium oxide is the main component. Gypsum is used as a coagulant and trace elements as additional components to coat rice seed, which promotes the absorption of nitrogen in soil and fertilizer by rice. Nitrogen fertilizer utilization rate of 7% to 12%, increase production 5% to 15%.
3.2.3 China Patent (CN1102944) has improved the formula reported by Specially Approved Sho 55-22045 and proposed (from calcium peroxide raw powder, mineral element compounds, trace elements, industrial and mining residues, water retention agents, independent accounting fungi and plant growth regulators. The composition of 35% calcium peroxide seed coating agent (the seed treatment agent used for direct seeding of rice) has excellent and stable biological effects, and the rice yield is high, saving a lot of manpower, material resources, land and time.
4 Others According to M.0. Mabbayal et al., herbicide-treated rice seeds can control paddy weeds. One method is to immerse rice seed in a certain concentration of solution and take it out after 24 hours. After laboratory tests, it is found that 2,4-D inhibits rice seed germination and rice root growth. Germination, but inhibited the formation of new leaves of rice, butachlor inhibited the length of rice seedlings is proportional to its concentration, butachlor, alkaloids have no effect on the growth of rice roots. The bensulfuron-methyl at various test concentrations did not affect the length of rice seedlings. The use of premix + fenicorim mixture, in addition to the highest concentration, generally does not affect the length of rice roots or rice seedlings. Another method is to put a suitable amount of herbicide in the plastic bag together with the ungerminated rice seeds before sowing, and shake it for about 5 minutes and take it out. Field trials in the wet and dry seasons found that with the exception of bensulfuron-methyl, all rice seedlings treated with herbicides were at the lowest level. The management of field water in the first few days after sowing is extremely important. In order to ensure the transplanting of wet sowing rice, paddy fields must have good drainage systems and water control systems.
It has been observed that treatment with bensulfuron-methyl has no effect on the number of rice stalks and the weight of rice plants, whereas seed treatment with pretilin + fenicorim mixture will reduce the number of rice stalks in early rice cultivars. The amount of the plant is slightly decreased, but the initial loss of the crop will be restored. The final yield of all the herbicide-containing plots exceeds that of the untreated plots, but there is no difference between each other.
From the above, it can be seen that the use of herbicides such as pretilin + fenchorim mixture and bensulfuron-methyl as seed treatment is feasible, and this method is used to prevent the risk of direct contact of farmers and by-products with herbicides. The field of mechanical sowing is most suitable.
China's rice planting area accounts for about 1/4 of the total planting area. 90% of the grain crops are propagated by seeds. Seedlings are the weakest stage in the process of crop growth and the weakest resistance to environmental bacteria and environmental impacts. Diseases such as stem nematode disease, bastard disease, and bacterial leaf streak eradication are in the bud stage.
Seed treatment has the advantages of protecting seed from soil-borne pathogens and harmful animals and herbicides, so that the seed can obtain enough nutrients to promote germination, growth, promote the symbiosis of nitrogen-fixing bacteria, and facilitate the promotion of standardized seed planting and other functions.
Ketone Test,Urine Rapid Test Strips,Animal Test Strip,Test Strips Diabetes Weight Loss
Changchun Medicon Technology Development Co., Ltd , https://www.teststrip.pl