Control of black rot of broccoli and exploration of high-yield cultivation techniques of edible fungi

Symptoms of black rot in broccoli

The black rot of broccoli is harmful to leaves and bulbs. Cotyledons quickly die or spread to true leaves after being immersed in water. There are two types of true leaf infection. The pathogen invades from water holes, causing leaf edge disease. The "V" shaped blight spot extending inward from the leaf edge begins to form. The pathogen spreads downward along the vein, forming a large necrotic area or irregular yellowish brown spot, and the leaf tissue at the edge of the spot is light yellow. Invading from the wound, an amorphous light brown spot can be formed in any part of the leaf, often with a yellow halo on the edge, and the spot extends to both sides or inside, causing the surrounding mesophyll to turn yellow or die. After entering the vascular bundles of the stem, the pathogen gradually spread to the bulbs or veins and petioles, causing the plant to wilt, until the wilting no longer recovered, and the corms were all black or rotten, but not smelly. Under dry conditions, the bulbs were black, and the serious leaf edges of broccoli were invaded in many places, resulting in the death of the whole leaves or partial or partial decay of the outer leaves.

Control methods of black rot of broccoli

(1) planting disease-resistant varieties such as Zhongqing No. 1 and No. 2.

(2) rotation with non-cruciferous vegetables for 2-3 years.

(3) collecting seeds from disease-free fields or disease-free plants.

(4) add 0.6ml acetic acid and 2.9ml zinc sulfate into 100ml water, control the temperature at 39 ℃, soak the seeds for 20 minutes, rinse for 3 minutes and then sow seeds. You can also soak the seeds with 45% Dysenamine 300 times solution for 15 minutes, then dry and sow the seeds, or use 50% copper succinate wettable powder according to 0.4% of the seed weight to prevent the occurrence of black rot in the seedling stage. In addition, 200g seeds can also be soaked in 15ml solution of agricultural antibiotic 751 and dried in the shade after adsorption, or each kg seed can be mixed well with bleaching powder 10g to 20g (active ingredient), and then sealed in a container for 16 hours, which can effectively control the black rot pathogen carried on cruciferous vegetable seeds.

(5) strengthen cultivation management. Sowing at the right time, not sowing too early, watering reasonably, squatting seedlings at the right time; pay attention to reduce the wound; clean the countryside in time after harvest.

(6) spraying 72% agricultural streptomycin sulfate soluble powder or 200 × 10mur6 or chloramphenicol 100 × 10mur6 or 27% copper noble suspension 700 times at the initial stage of the disease. Stop taking medicine 5 days before harvest.