Soybean Disease Control Technology: How to Use Junke Duke

Junke Duke (2% Ningnanmycin aqueous solution) is a brand-new biological pesticide successfully developed by the Chengdu Institute of Biology, Chinese Academy of Sciences. It features high efficiency, a broad spectrum, environmental friendliness, and the ability to promote crop growth and improve quality and income. It has a very good control effect on soybean root rot, phytophthora blight and other diseases.

I. Control of Soybean Root Rot

1. Symptoms When infected at the seedling stage, brown oval, elongated or irregular lesions form on the diseased plants and the base of the stems, slightly sunken, then developing into large patches surrounding the main stem and even damaging the lateral roots. In the later stage, the roots of diseased plants turn dark brown, the epidermis rots, and the lateral roots and fibrous roots are few or necrotic. The diseased plants are stunted and yellow, and the lower leaves drop early. Except for a few seriously damaged at the seedling stage, diseased plants generally do not die, but they bear few pods and few seeds, affecting yield.

2. Chemical control methods Seed disinfection method, that is, before sowing, use 2% Junke Duke aqueous solution (dosage is 1-1.5% of seed weight) for wet seed dressing, then pile and cover, dry in the shade, and sow. In areas where underground pests occur during the soybean seedling stage, it can be mixed with organophosphorus insecticides. If root rot occurs during the soybean growth period, use 2% Junke Duke aqueous solution diluted 200-260 times plus Xiaoyedi or foliar fertilizer to spray the plants, which has a good control effect on soybean root rot. After a few days, the wilting and dead plants of soybean can be relieved, the leaf color returns to normal, and a bumper harvest can still be achieved. This technology has been widely promoted and applied in the main soybean production areas.

II. Control of Soybean Phytophthora Blight

1. Symptoms The disease can occur throughout the entire growth period. The pathogen can infect the roots, stems and leaves of plants, causing root rot, stem rot, plant stunting and wilting. After sowing in the field, it causes seedling rot. Seedlings collapse before or after emergence, and the damaged roots become soft and brown. At the true leaf stage, the stems of damaged seedlings are water-soaked, and the leaves turn yellow, wilt and quickly die. When adult plants are damaged, the first symptom is yellowing of the veins of the lower leaves, and the upper leaves quickly lose green, followed by the wilting and death of the entire plant, with the damaged roots turning brown.

2. Chemical control methods Chemical seed dressing: use 2% Junke Duke aqueous solution at a pesticide-to-seed ratio of 1.5:100 for wet seed dressing (1500 ml of pesticide to dress 100 kg of soybean seed), then pile and cover, and sow after drying in the shade. If the disease occurs during the growth period, dilute 2% Junke Duke aqueous solution to 250-300 times and spray, with uniform coverage and no missed spraying as the standard, for a better control effect.

III. Control of Soybean Mosaic Virus Disease

1. Symptoms The leaves show mosaic, shriveling or mottling, leaf curling and yellow blotches. Some form pathogen or lesion necrosis along the main veins, some have vein necrosis, and some form top necrosis. Diseased plants infected at the seedling stage are stunted, and the seeds produced by diseased plants are generally brown-speckled seeds or mottled beans.

2. Chemical control methods Start using the pesticide when the disease is about to occur or at the early stage of occurrence. Dilute 2% Junke Duke aqueous solution to 250-300 times and spray, with uniform coverage and no missed spraying as the standard. Apply continuously 2-3 times, with an interval of 7-10 days each time. If aphids occur in the field, it can be mixed with imidacloprid, foliar fertilizer, etc., for a better effect.

IV. Control of Soybean Sclerotinia Stem Rot

1. Symptoms This disease mainly damages the stems of plants, mostly starting from the branching area in the middle and lower parts of the main stem. The lesions are water-soaked, irregular, light brown or nearly white, can surround the stem and spread upward and downward. In the field, the browning and death of the upper leaves of plants is the first thing to attract attention.

2. Chemical control methods At the stage of sclerotium germination and invasion, use 200-250 ml of 2% Junke Duke aqueous solution per mu and spray evenly with water.

Because several years of promotion and application have proved that this technology has a very good control effect on various soybean diseases, it is recommended to carry out large-scale demonstration and application in future soybean production so as to give full play to its social benefits.