Cotton wilt disease is one of the major diseases causing cotton seedlings. The peak season of early cotton in North China was in late May, resulting in a large number of dead seedlings, especially those with severe crop failure and severe verticillium wilt. It was too late to make up for a serious shortage of seedlings. Therefore, the early occurrence of wilt disease is an important factor hindering cotton production in central cotton production areas, and it is also a problem that cotton farmers in wards feel very headache. In recent years, the early occurrence of cotton wilt has been increasing year by year. The early onset of Fusarium wilt usually begins from the cotyledon stage and reaches the peak of 3-4 true leaf stages. At this time, the nutrient supply from the seedlings of the seedlings has been weaned, and the secondary roots of the cotton seedlings are not yet developed, and the ability to absorb nutrients is also preserved. It is very fragile, so it is most likely to cause dead seedlings.
First, the symptoms of early onset of wilt disease generally cotyledon first disease, the formation of necrotic spots on the edge of the cotyledon, gradually expanding, dry, fall off, and some cotyledon veins turn red first, the leaf veins between the yellow and flaking yellow, wilting; serious disease after the real leaf by From the bottom to the top of the disease, some suddenly wilted, scorched, and died, and some of them gradually drank and curled inwards along the edges of the true leaves. The veins remained green, and the mesophyll gradually faded to form yellow-greenish watermelon rind; this year due to low temperature Affected, cotton sowing later, the incidence of late than usual, entered the rapid development stage on May 20, is expected to peak in the end of May in early June.
Second, the prevention and control measures to prevent the early occurrence of wilt disease is the basic measure of selection of disease-resistant varieties, in addition to more effective agriculture, chemical control and remedial measures are:
1. The cultivator plan. The cultivator can increase the permeability and temperature of the soil, which is not only beneficial to strong seedlings and early-onset hair, but also improves the disease resistance of the cotton seedlings, and at the same time enables the diseased cotton seedlings to recover as soon as possible. Therefore, the cotton field should be maintained from shallow to deep. Principles, to do cultivating, fine cultivating.
2. Dynamize seedlings in cotton fields that have experienced severe disease over the years. Severe incidence of cotton fields, the general incidence of 20% to 30%, more serious up to 50%, but the disease will not completely die of seedlings, enter the early June when the high temperature, the disease will quickly recover. Therefore, disease-heavy cotton fields should be re-set after the onset of wilt disease to prevent the emergence of ridges.
3. Effective pharmaceutical control measures. 50% carbendazim spray 800 prevention, early onset: Verbendrobium, fulvic acid irrigated roots, grams of yellow dry, thiophanate-methyl and other pesticides, adding 1% urea spray water control.
4. Remedial measures. For cotton fields that are caused by wilt disease due to premature defoliation and early morbidity, after the onset of the peak in early June, large seedlings may be transplanted for remediation. The specific method is to use the shovel in the absence of seedlings to remove the soil. Pull out, form a wedge-shaped hole, and then take the seedlings, also deep in the left side of the seedlings to dig a hole, slowly pull out the cockroach, right dig a seedlings out of the seedlings, carefully put the seedlings into the dug hole, four sides with The foot is solid, so that the soil is tightly connected, so that the cotton seedlings do not hurt the roots and the soil is not loose. This method of large-scale transplanting, not watering, not slow seedlings, the survival rate of up to 95%.
Finished Products of varicella vaccine. It has three qualities,good safety of gelatin-free, long validity period by good stability, better protection with high titer and immune efficacy. These improvements enhanced the vaccine safety and quality, and established BCHT the leading position in varicella vaccine. We have two different packages, penicillin bottle and pre-filled syringe. And it has been exported to other countries, such as India, Philippines.
Finished Products
Finished Products Of Rabies Vaccine,Rabies Vaccine For Human Use,Live Biotechnology Chicken Pox,Live Lyophilized Vaccination
Changchun BCHT Biotechnology Co.,Ltd , https://www.ccbcht.net