First of all, 16% of the evil lines are clear to control the "spikelet head" of rice.

For many years, the phenomenon of "spikelet head" (also known as spikelet warping) under multi-variety, multi-planting level and multi-ecological conditions has occurred in large-scale production in Jiangsu and other major rice production areas, which is characterized by small spikes and small glumes. After grain filling, the inner shell is cracked, part of the rice grains are exposed, the rice is small and beige black and brown. The occurrence is particularly serious in the Lixiahe area, coastal area, along the Huaihe River, along the Huaihe River, along the hills and other areas in Jiangsu Province. It is estimated that in recent years, the affected area of Jiangsu Province alone is about 100000 hectares per year, reducing rice production by more than 100 million kilograms, resulting in a cumulative loss of rice production of about 500 million kilograms. It is generally believed that improper cultivation and management techniques, climate, soil, fertilizers, pesticides and other conditions, evil seedling disease, rice blast and stripe blight and other factors or several factors are the main causes of "spikelet head" formation. It is also believed that "spikelet head" is caused by species degradation or seed quality problems.

In recent years, Dahua seed Group of Jiangsu Province has carried out cooperative research with the Institute of Plant Protection of Jiangsu Academy of Agricultural Sciences and Zhenjiang Institute of Agricultural Sciences in hilly areas of Jiangsu Province. after a large number of on-the-spot investigation and analysis, it was found that there was no significant difference in the carrying rate of Fusarium between "spikelet head" and healthy spike grain, but "spikelet head" carried nematode, and normal spike did not carry nematode. Therefore, it is suggested that the harm of dry tip nematode disease is the direct cause of the phenomenon of "spikelet head".

The seeds of Wuyunjing 7, Zhendao 2 and Wuyujing 3 were treated with 25% of the commercial seed soaking agents commonly used in production, including Baig, 4.2% Zinfeng, 16% Badan and 95% Badan, and the conventional cultivation management was adopted. The results of field experiments showed that 95% Batan had the best control effect on "spikelet head", reaching more than 97%; 16% Badan had a control effect of about 95%; 4.2% soaked seeds had a control effect of about 90%; and 5% had a control effect of less than 15% after seed soaking treatment. Because 16% Aexianqing is a mixture of Batan and Prochloraz, it can treat both dry tip nematode disease and evil seedling disease. From the experimental data, it seems to have a better control effect on rice varieties such as Wuyujing 3, which is easy to be infected with dry tip nematode disease. Therefore, in the spring of 2003, Dahua Branch proposed to popularize the compulsory supporting measures of seed treatment with 16% chlorpromazine for seed treatment, covering an area of nearly 4 million mu. The occurrence string of "spikelet head" in the field treated with this chemical is really very low, and there are no seed quality and disputes caused together, which has received good social benefits.

The results suggest that at present and for a long time in the future, rice production should not only pay attention to the control of evil seedling disease, but also attach great importance to the prevention and control of stem tip nematode disease. At present, the most economical and effective control method should be seed soaking treatment, in which 16% Xiexianqing is the first choice, which can achieve the best control effect on evil seedling disease and dry tip nematode disease.