Downy mildew is the most common and most harmful disease in production. It occurs in every planting area in China, especially in the rainy and humid seasons. It has the characteristics of great harm, rapid outbreak, and being difficult to be controlled, etc. Once it breaks out, and If the prevention has not taken in time, it will not only cause a lot of dried-out leaves, young fruits, fruit clusters, etc., but also cause the branches to fail to develop and mature normally, affect the flower bud differentiation, and it can lead to dead branches and tendrils in severe cases. This is what fruit growers call "anthracnose destroys production and downy mildew destroys the orchard".
Understanding Downy Mildew
The pathogen of downy mildew are obligatory parasitic bacteria belonging to the Mastigomycotina, Oomycetes, and Peronosporales. The mycelium expands and spreads between the host cells, and extends into the host cells to absorb nutrients with tumorous haustoria.
Downy mildew mainly damages the leaves. After the leaves are damaged, some water-stain-like spots will appear first. Then the spots will expand into dark disease spots, and finally merge into large spots. At the same time, the downy mildew has strong infection ability , spreads rapidly, and occurs rapidly, which not only damages the leaves, but also infects the flower buds, fruit axis and fruit grain.
Prevention of Downy Mildew
Downy mildew generally starts to occur in the middle-late growth stage of the crops. Once downy mildew occurs at this time, the leaves will be definitely affected, and the efficiency of producing photosynthetic product will decrease. So once downy mildew occurs, the growth of plant should be adjusted in time, especially in severe cases. After the disease spots are controlled, the new leaves should gradually replace the leaves which with the diseased spots and become the main functional leaves, and then wait for the seedlings to fall, so that the efficiency of photosynthesis can be restored and the yield of crops per unit time can be improved.
Defeili
(32% pyraclostrobin·fluopyram SC (24+8))
Two major effects:
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It has strong permeability and longitudinal conduction activity. After application, it is redistributed on the leaf surface of the plant- the effect of the fungicide is fully absorbed.
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It can increase the activity of nitrate reductase in plants, thereby increasing the supply of nitrate nitrogen, avoiding premature aging of leaves, and maintain nutrient synthesis ability of functional leaves -restoring the efficiency of photosynthesis.
Ps: Defeili+Duca is more effective~
