How to control bacterial wilt of white sesame seeds after rainstorm in summer

White sesame bacterial wilt is mainly caused by excessive soil moisture in the field. The pathogen overwinters with the diseased plant residues of white sesame in the soil and spreads through running water and farming operations. The condition of continuous cropping is even worse. The incidence peak, hot from July to August, after the rainstorm, the temperature rises suddenly, the bacterial wilt of white sesame is easy to occur and epidemic.

Sesame bacterial wilt

I. harmful symptoms

Ralstonia solanacearum of white sesame is a bacterial disease. the outer part of the rhizome of the damaged sesame plant shows dark brown stripes, internal vascular bundles, brown, bacteria overflow and exudate, and become black and bright particles after drying. At the initial stage of the disease, the diseased plant seemed to be lack of water, wilted during the day and returned to normal at night. A few days later, the sesame leaves wilted sharply from the top down, the old leaves hung, and then the whole plant died. After the onset of the disease, the veins of the leaves show dark green spots, sometimes crisscross, forming a network, facing the light perspective, and its center is oily. After the capsule of sesame was damaged, it showed waterlogged disease spot, and gradually turned into dark brown stripes of different thickness, which made the diseased capsule thin and shrunken, thus making the sesame seed thin and lost its ability to germinate.

Second, prevention and control technology

(1) Agricultural prevention and control

1. Select disease-resistant sesame varieties and rotate them with non-Solanaceae and non-legume crops for three years.

2. White sesame is not resistant to water stains. During the growth period, if there is heavy rain or heavy rain in the field, it should be eliminated in time. There is no stagnant water in the field when the rain stops.

3. Increase the application of organic fertilizer, especially potash fertilizer.

4. Remove, destroy or bury the diseased plants in time.

(2) Chemical control

1. Disinfect the acupoint with 1 part of lime water and 15 parts of lime powder.

2. Before sowing, the soil is treated with chlorothalonil, and the preventive effect is better; or in the early stage of sesame disease, spray with 50% carbendazim wettable powder 800-1000 times or 50% cresol guaiacol 50 ml plus 50% carbendazim 100 grams per mu, spray with 50 kg water.