MySheen

Control of Phytophthora Leaf spot of Pineapple

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, Pineapple stem spot leaf spot is a common disease, which is a kind of leaf spot disease, which mainly harms the leaves and affects the photosynthesis of leaves, resulting in the abnormal growth and development of fruit trees. The symptom is that the leaf spot is damaged in the middle of the leaf, and the disease spot is long at first.

Phomopsis leaf spot of pineapple is a common disease, belonging to one of leaf spot diseases. It mainly damages leaves, affects photosynthesis of leaves, and leads to abnormal growth and development of fruit trees.

Symptom Phomopsis leaf spot infects the middle of the leaf. The initial lesion is oblong or irregular, flat, pale yellow at the edge and honey yellow in the center. Black spots were buried under the epidermis of the central spot, which were conidia of the pathogen.

Phomopsis anassae Xiang et P. K.Chi was the pathogen of leaf spot. conidia punctate, solitary or connate, buried under epidermis, blackish brown, globose or irregular. Type A conidia are colorless, single celled, spindle or oval, with two oil spheres; Type B conidia are colorless, single celled, linear, curved.

The pathogen overwinters on diseased leaves mainly in the form of mycelium. In the coming year, when the conditions are suitable, the pathogen produces a large number of conidia, which are mainly transmitted by wind, rain and insects. The parasitism of germs is weak and invades through wounds. In the cultivation and management of fruit trees, orchards with extensive management and weak fruit growth potential are easy to develop diseases. The disease likes high humidity environment, so we should pay attention to it in the process of prevention and control.

control methods

(1) Strengthen orchard management, fertilize and irrigate rationally, strengthen tree vigor and improve tree disease resistance. Scientific pruning, pruning dead branches and diseased leaves, adjusting ventilation and light transmittance, paying attention to drainage measures, reducing orchard humidity and maintaining moderate temperature and humidity of orchard. Combined with pruning, clearing orchards, removing diseased leaves and dead leaves in time to reduce disease sources.

(2) Chemical control can be sprayed when necessary. The available chemicals are 500-800 times of 50% carbendazim WP or 500-800 times of 50% topozine WP.

Commonly used drugs carbendazim, topzin.

 
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