Pest control techniques for Paddy growth stages

Seedbed pest management

The seedbed period is an important period for rice cultivation and the key to future yield increase. The management of the seedbed period can be summarized in eight words: not dry, not wet, not cold, not hot. If rice encounters unfavorable humidity and temperature during the seedbed period, it will easily encounter pests and diseases, which will seriously affect the subsequent transplanting and cultivation of seedlings.

Specifically, not dry means that the soil needs to maintain moisture; non-wet refers to both watering and less watering; not cold means blocking the vent when it is cold; if not, it means turning on the ventilation at high temperature. mouth. The small way to judge the soil moisture is to hold the soil in the hands and naturally form a mass, which will spread on the ground. This humidity is most suitable for the growth of various crops.

The three most common diseases in the seedbed period are: cotton rot, blight and bacterial wilt. Rice is prone to cotton rot at low temperatures. With the rice rot disease, the nutrients in the endosperm will be consumed in large quantities, and it is impossible to grow into strong seedlings. To prevent cotton rot, it is necessary to use copper hydroxide and aluminum triethylphosphate to prevent cotton rot before watering after sowing.

Cotton rot

 

When the humidity is too high, the pathogens of the blight will break out, and the diseased rice is prone to lack of seedlings. Even if the seedlings are successfully emerged, the rice seedlings may not be strong enough. To prevent the blight of the disease, it is necessary to compound the cyanosin and the carbendazim in the key period when the rice grows to one leaf and one core (one leaf and one core after emergence) and two leaves and one core (the needle period). Blight, fungicides and increase the amount of medicine to promote the growth of seedlings.

After encountering high temperature, rice is susceptible to bacterial wilt. The pathogen of bacterial wilt, but because the rice is not strong enough, the leaves of rice will be dry and dry.

Bacterial wilt

 

Reforestation management of pests and diseases

The greening period refers to the period from 7 to 10 days after rice transplanting, and the rice seedlings change from yellow to green. When the rice seedlings turn green, they immediately enter the tillering stage. The rice seedlings will become stronger and the leaves will increase. The tillering stage is the key to rice growth. The good or bad of tillers can directly determine the later yield.

During the tillering period, rice absorbs a lot of nitrogen, which is also the period when nitrogen fertilizer is most needed. During this period, the various organs of the plant are relatively delicate and vulnerable to various pests and diseases. The most important pest is rice planthopper, and the most important disease is sheath blight.

Rice planthoppers mainly occur in the south, and this pest destroys the cell tissues of rice and absorbs nutrients, which makes it difficult for rice ears to grow. Once the rice planthopper breaks out, it lasts for a long time and can easily lead to large-scale production cuts. The control of rice planthopper has been relatively mature, and the use of neonicotinoids such as pymetrozine and dinotefuran has superior insecticidal effects against rice planthopper.

Rice planthoppers grow mainly in areas close to the water

 

Sheath blight is also very common in the South. This is a fungal disease. It is mainly controlled by triazole drugs such as ether methylcyclazole and propiconazole. The effect of adding penetrant is better.

In the northeastern region, the common insect pests are the northeast leaf miner and the rice chironomid larva. Among them, the rice larvae are a new outbreak of insect pests in recent years. They will feed on the roots of rice and eat rice seeds. The control of red and white nematodes is complicated, and it is necessary to use chlorpyrifos, fluvalinate, high-content acetamiprid or flubendiamide for drug compounding, and evenly sprayed into the water.

 

Jointing pests and diseases

At the jointing stage, the most common pests in the southern part are the mites and rice mites. These two pests cause the rice to be empty and the rice ears are white, which seriously affects the yield.

Low-necked two-in-one aphids are better for prevention and treatment because of poor drug resistance. For older worms, it is necessary to increase the dosage. It is recommended to use a compound of a vitamin salt or a chlorantranil hydrochloride and a tricyclic azole. These pesticides are highly permeable and have low resistance to pests.

The disease in this period is rice blast. The best time to control rice blast is 5-7 days before the rice ear rupture period. The traditional medicinal rice blast and pyriazine are effective.

Paddy is infested by mites

 

Pest control

The booting stage, heading stage, and fruiting stage are collectively referred to as the ear stage. The focus of prevention and control during this period is rooting, leaf conservation, grain supply and weight gain. The core purpose of the medication is to preserve the leaves and preserve the ears.

As with rice blast, it is recommended to use tricyclazole, indigo, pyraclostrom and epoxiconazole in the panicle, and the effect will be better after compounding. At the same time, due to the relatively thin rice seedlings at the earing stage, it is necessary to add an auxiliary agent to make the drug easier to adhere to the diseased part.

Interpretation

This is the leaf color change and nutrient transfer that occurs during each period of rice physiological process. Many farmers like rice seedlings to always look green, which is actually a violation of the growth pattern of rice.

The first color change occurred between the tillering stage and the jointing stage. At the end of the tillering stage, the rice seedlings turned yellow because the rice had absorbed the nutrients in the paddy field; the color change of the second rice seedling occurred in the booting stage after the jointing stage. During the period, a large amount of fertilizer began to shift, and the rice leaves began to turn green. The third color change is at the heading stage, and the leaves become dark green after absorbing nutrients.

Inverted four leaf protection

Pour four leaves is the most important concept in rice growth. How much dry matter can be produced by rice ears depends on the four rice leaves. For example, if you do not pour a leaf, it will reduce production by 41.8%.

Protecting these four leaves is a very important task. After heading or breaking, in order to protect the four leaves, it is necessary to repeatedly sterilize.

Pyraclostrobin can prevent rice blast, promote photosynthesis and inhibit respiration. Propiconazole has strong permeability and can penetrate into plants in a large area. It protects the strongness of the four leaves and grows more evenly, which helps to increase production. .

question Time

1. What kind of foliar fertilizer should I use for rice?

When rice is grown to two leaves and one core, amino acid and biological fertilizer can be used together with the fungicide, and they can effectively promote the rooting of rice seedlings.

2. What kind of agent can be used to promote the effect of fungicides and insecticides?

When using insecticides or fungicides, the addition of zinc fertilizer and boron fertilizer can promote the absorption of fungicides and insecticides, and improve the resistance of rice to insects and diseases.

3. What is the problem with ammonia poisoning in rice?

Ammonia poisoning is mainly caused by nitrogen fertilizer and straw fermenting in the soil. The treatment method is to drain the water and carry out the drying of the field. If it is not possible to drain, the residual leaves should be cleaned. Poisoning has occurred, foliar fertilizers, or water-soluble fertilizers can be used to prevent ammonia production.

4. Many farmers believe that when rice is sprayed, it is necessary to have a large amount of water to have an effect. How to crack this situation?

In the severe area of ​​rice blast, it is necessary to increase the amount of water. If the rice blast is not serious, it can be ensured by using the medicinal compound. The most important factor is not the amount of water, but sufficient active ingredients per unit area.

5. How to increase rice yield?

Increasing yield is essentially to preserve the yield of rice, such as preventing rice blast at jointing stage, using potassium fertilizer to increase the fullness of the ear at the booting stage, and using appropriate techniques in each period is a way to increase yield.

6. What should I do if the output of the saline-alkali land is low?

First, the sooner the field is better, the conditions are allowed, often drained; second, the use of biological fertilizer; third, soil testing and fertilization, to avoid ammonia poisoning in saline-alkali.

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