A Detailed Guide to the Latest Techniques for Black Nightshade Disease and Pest Control

Black nightshade (Solanum nigrum) is a plant with relatively strong resistance to pathogens, so when problems occur they are mostly caused by pests and diseases, with fewer cases caused by disease alone. In daily life people use it as a medicinal herb, and it has a good effect on clearing blood and dissolving stasis. So what diseases and pests generally affect black nightshade? Qin Nong Wang takes you through them.

1. Stem base rot

This is very easily caused by incomplete disinfection of the planting soil or by years of continuous cropping. First the plant shows wilting, wilting from the roots upward, and finally the leaves begin to rot, rotting from the top downward. Once this condition appears, for the time being it is best not to plant there, or to carry out crop rotation, and wait until the virus content in the soil is lower before planting. The common solution is to spray a disinfectant, applying products such as Bacillus subtilis and hymexazol to the planting area, once a week for one month.

2. Aphids

This is a parasite that black nightshade is relatively prone to, mostly appearing on the surface and easily spotted with the naked eye. The symptoms are pale yellow egg-like objects on the leaf surface, in dense patches, some distributed in spots. Then the leaves slowly curl into a cylinder shape and turn yellow. In daily care, all kinds of residues in the field soil need to be removed to reduce pathogens. When this problem appears, the affected leaves need to be removed, and the plants need to be sprayed with 0.5 matrine aqueous solution at 600-1000 times dilution, and the surrounding plants also need to be sprayed.

3. Spider mites

This is a pest that easily causes black nightshade to drop its leaves, and it generally attaches to the underside of the leaves. The symptoms are that the leaf surface clearly tends to wilt, and afterward white spots appear on the leaves, with holes appearing in some places. When the white spots cover the entire leaf, the leaf falls off directly, and when you turn it over you will find the underside is already completely covered with mites. It is recommended to spray the plants with 20% fenpropathrin emulsifiable concentrate at 2000 times dilution.

4. Ladybirds

This is the pest most harmful to black nightshade, as it directly uses the black nightshade leaves as food, and in severe cases will even eat the branches and stems. The symptoms are that where the ladybirds attach, the leaves become incomplete or develop holes, while some leave the leaf epidermis on the sun-facing side and eat away the other parts. At this point, pesticide must be sprayed promptly; 40% chlorpyrifos emulsifiable concentrate at 2000 times dilution can be used.

Treatment for the above problems must be timely, and residues are best taken away and burned to avoid infecting other plants. Daily clearing of the farmland must also be thorough, as many pests and diseases are caused by residues. So special attention must be paid to this aspect.