It is common to plant diseases, and some of them have become a major obstacle to planting today, such as the root knot nematode that we will talk about today. Let's take a look at the harmful symptoms and control measures of root-knot nematodes with Xiaobian.
According to statistics, in recent years due to over-reliance on the fertilizer to promote crop production increase, so that the apparent acidity of the soil. The most typical symptoms are: soil surface grow moss or red. Root-knot nematodes like acidic soils, and their hazards have been significantly increased year by year. Generally, crop yields can be reduced by 10%-35%, and seedlings often occur frequently. And, more emphasis on root-knot nematodes harm crops damping-off, wilt variety of soil-borne diseases, root rot and other mixing occurs, extremely difficult to treat.
The symptoms of root knot nematode are: wilting before and after noon, early in the morning, but still recovering in the morning and evening, and the plant can no longer grow normally or even die. The hazard process is: the roots are formed by the second instar larvae drilling into the roots of the vegetables, so that the roots no longer have capillary root growth, and in severe cases, larger nodules are formed. After the plant is infested, it loses its ability to absorb water and nutrients.
1. Agricultural control measures:
Rotation can reduce the occurrence of root knot nematodes. When transplanting, the infected plants must be removed or the "root nodules" removed. Deeply turning the soil to less than 25 cm can reduce the occurrence of pests.
2. Biological control measures:
Re-applying the decomposed organic fertilizer, increasing the application of phosphorus and potassium fertilizer, improving the disease resistance of the plant, adding lime in the base fertilizer, and chasing the superphosphate leaching solution on the leaf surface, can also obviously control and alleviate the root knot nematode disease.
3. Chemical control measures:
At present, the nematicides allowed for vegetable production in China include 3% avermectin water emulsion, 20% thiazolyl water emulsion, and 20% thiazophos granule.
(1) Spreading: Use thiazophos granules 2-5 kg ​​per acre to spread evenly with the fertilizer and then into the soil.
(2) Irrigation root: choose fine weather, use 3% avermectin 1500-2000 times after 10 o'clock, each plant according to the size of 100-250 ml irrigation root, or 20% thiazophos 1500-2000 times liquid, each strain 200-250 ml irrigation roots.
Pesticide rooting follows two principles of change:
First of all, the amount of liquid should change. For the seedlings, two or two liquids are enough. For the adult plants that are already in the fruiting stage, the half a catty is obviously not enough. At best, only the plants can be infiltrated. The main root system. For a large number of capillary roots in the soil, half a catty of the liquid is not infiltrated to that depth, so it is impossible to infiltrate the capillary root. Compared with the main root system of vegetables, the capillary roots are more susceptible to infection by pathogens, and the disease is naturally prone to occur without the protection of the drug. Therefore, when the adult plants are root-rooted to prevent pests and diseases, the amount of liquid medicine needs to be increased, so that the disease prevention effect is good.
Second, the concentration of the drug should be changed: the concentration of the rooting agent is small, and the concentration is large, and it is easy to damage the root. The concentration of the liquid is preferably not higher than 1500 times. For example, when the vegetable seedling stage is small, the root system is tender and the drug resistance is poor. In this period, the concentration of the drug should be lowered to prevent the root system from being phytotoxic. In summer, the concentration of the drug should be slightly lower, in order to achieve the desired control effect.
The above is the hazard and prevention measures of root knot nematodes compiled by Huinong. I have learned it? If you want to know more about agricultural technology, please pay attention to the Hui Nong School!
Selected raw materials, deep roasting and frying, give the coffee a balanced taste
Mellow milk fragrance, long finish, showing delicate baking aroma
Instant Coffee Powder,Instant Espresso Powder,Grinding Coffee Powder,Espresso Powder Supermarket
KARAK , https://www.jskarak.com