Control of bacterial wilt of black sesame

Black sesame has a significant role in medical and health care, which can delay aging, moisten the five internal organs, strengthen muscles and bones, replenish strength, nourish liver and kidney, and nourish spleen and lung. On the other hand, the bacterial wilt of black sesame is very common in production, which has a severe effect on its yield and quality. the disease characteristics and control techniques are as follows:

I. occurrence conditions

Black sesame bacterial wilt is mainly caused by excessive soil moisture in the field. The pathogen overwinters with the remains of the diseased plant in the soil and spreads through running water or farming operations. The disease in the continuous cropping field is more serious, and the peak of the disease is often in the hot July to August. After the storm, the temperature rises suddenly, which is conducive to the epidemic of the disease.

Second, harmful symptoms

Black sesame bacterial wilt is a bacterial disease, which invades from the root wound or natural orifice and spreads from the bottom up in the plant vessel. The outer part of the rhizome of the damaged plant showed dark brown stripes, the inner vascular bundles were brown, and bacteria overflowed and exuded, which turned into bright black particles after drying. At the initial stage of the disease, the diseased plant seemed to lack water, wilted during the day and returned to normal at night. A few days later, the leaves wilted sharply from the top down, the old leaves hung down, and then the whole plant died. After the onset of the disease, the veins of the leaves showed dark green spots, crossed vertically and horizontally, formed a network, welcomed the light perspective, and its center was oily. After the capsule is damaged, it shows waterlogged disease spot, and gradually turns into dark brown, different thickness stripes, so that the diseased capsule shrinks, close and makes the seed thin and shrivelled, losing the ability of germination.

III. Prevention and control techniques

(1) Agriculture

1. Disease-resistant varieties were selected and rotation was conducted with non-Solanaceae and non-legume crops for three years.

two。 To do a good job of field drainage, black sesame is very sensitive to water, so that there is no stagnant water in the field after rain.

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

4. Remove and burn the diseased plant in time.

(2) Chemical control

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

two。 It is better to treat soil with chlorothalonil before sowing, or to spray 50% carbendazim wettable powder 800 to 1000 times or 50% cresol per mu plus 50% carbendazim 100 grams per mu and 50 kg of water at the initial stage of the disease.