Corn top rot is a newly emerged disease in recent years. It has been increasing year by year, causing great damage and production. Mp Filter,Mp-Filtri Filters,Industrial Mp-Filtri Filters,Mp-Filtri Filter Element Henan Sinofiltec Technology Co.,Ltd , https://www.airfilters.pl
Top rot occurs during the whole growing season of corn, and different growth stages show different symptoms. During the seedling period, the diseased plants grew slowly. The edges of the plants were chlorotic, shrinking and distorted. Yellow streaks appeared. The stems of the diseased plants were grayed, browned or darkened, and the whole plant died. In the adult plant stage, the diseased plants are more or less dwarf, and dwarfing is not obvious. Other symptoms are diversified. (1) Leaf edge nick type. The basal part or margin of the diseased leaf appeared knife-cut nicks. The chlorosis of the leaf margin and the top of the diseased leaf appeared bright yellow. In severe cases, half or all leaves of the leaf blade fell off, leaving only the leaf mesophyll tissues of the midrib and midrib. (2) Leaves dead type. The edges of the leaves are rotted at the edges of the leaves and the leaves are sometimes torn. In severe cases, the tip or leaves of the top 4 to 5 leaves are dead. (3) twist wrap type. The top leaves are curled upright and long whip-like, some are wrapped by other leaves when forming a whip, and cannot be stretched to form an arch; some top leaves are distorted by twisting and the entangled leaves are often wrinkled. . (4) leaf sheath, stem rot type. The base of the leaf of the panicle becomes brown and rot. Sometimes the scaly cortex on the inside of the leaf sheath and the stalk is also rust-colored. The vascular bundles and stem sections in the stem show brown streaks, and some appear hollow. Or pink mold, easy to fold when windy. (5) Elbow type. The leaf bases and stems of the ear were yellowed, the leaf sheaths and stalk tissues were softened, and the plant tips sloped to one side. (6) Parietal clumps. (7) Abortive or empty stalk type. Mildly diseased plants can bear heading and fruiting, but the ear is small and the seeds are few; the seriously ill strains cannot head or form empty stalks.
Maize top rot is mainly caused by Fusarium infestans in the soil. The pathogen mainly overwinters the mycelium on the diseased body, and invades through the pores, water holes or wounds of the plant the following year. Afterwards, the pathogen produces conidia with the aid of rainwater. Re-infected by retransmission. The incidence of low-level fields is heavy, and the corn trumpet season is prone to persistent high temperature and high humidity weather. The disease resistance of different corn varieties was different. Chidan 20 and Zhengdan 958 were more susceptible and the incidence was serious. Wounds caused by pests such as thrips and roundworms are conducive to the invasion of pathogens and can also increase the occurrence of top rot.
For the prevention of corn top rot, comprehensive measures should be taken. (1) Agricultural control. Remove the diseased plants in time and destroy them in a centralized manner. Serious illness fields should be turned down. Corn enters the big bell-mouth period and applies nitrogen fertilizer in time, spraying zinc fertilizer and growth regulators at the same time to improve the plant's resistance to stress. The sticking leaves were found and promptly opened with a blade. The diseased tissue quickly dried out when the plants were dry, and the disease stopped expanding. The tassels could also be extracted normally. (2) Chemical control. First, the chemical seed dressing, commonly used drugs 75% chlorothalonil WP, 50% carbendazim WP, 80% mancozeb WP, etc., seed weight 0.4% of the drug seed dressing. The second is spraying control, which can be diluted with 50% carbendazim WP or 80% Mancozeb WP in the early stage of disease. Add appropriate amount of ZnSO4, unscrew the sprayer of the Knapsack sprayer, and aim at the corn leaf from the Spray irrigation from top to bottom, 80 ml per strain. You can also use 58% Methodyl Manganese Zinc Wettable Powder 300 times, or 50% Carbendazim Wettable Powder 500 times, or 75% chlorothalonil WP 500 times, every 7 to 10 days Continuous control 2 times. Adding potassium dihydrogen phosphate and other foliar fertilizers when spraying can improve the disease resistance of plants.