What is grape yellow leaf disease and what medicine should be used
Grape yellow leaf disease is a common disease that troubles grape growers, not only affecting the efficiency of photosynthesis, but can also lead to the withering and death of the plant in severe cases. This article will systematically analyze the comprehensive prevention and treatment plan for grape yellow leaf disease from three dimensions: pathological characteristics, causes of the disease, and scientific prevention and treatment.
Typical Symptoms and Treatment Plan for Grape Yellow Leaf Disease
Identification Features of the Disease
In the early stage of the disease, there is a spotted chlorosis between the leaf veins, which forms large areas of yellowing patches as the disease progresses, especially in the new shoots. The root system of the diseased plant develops poorly, and the fruiting rate significantly decreases.
Special Medication Use Plan
Immediately spray a mixture of 0.3% ferrous sulfate and 0.1% citric acid at the early stage of the disease, spray once every 7-10 days, and continue for 3 times. It is recommended to apply the medicine on cloudy days or in the evening to avoid the strong light affecting the efficacy. For severe cases, a chelated iron solution can be used for stereoscopic treatment by root irrigation.
Three Major Causes of Grape Yellow Leaf Disease
Climatic Causes of the Disease
Continuous rainy weather in autumn can trigger secondary diseases such as white rot and downy mildew, leading to the depletion of nutrients in the tree. Statistics show that in areas with consecutive rainfall for more than 5 days, the incidence of yellow leaf disease increases by 47% the following year.
Soil Physicochemical Imbalance
When the soil pH value is >7.5, the iron fixation rate can reach 92%. Experimental data show that in alkaline soil, the absorption of active iron by grapes is only 1/5 of the normal value, which is the main cause of iron deficiency yellowing.
Variety Resistance Difference
The 'Jufeng' series of varieties have weak disease resistance, with an incidence rate 3.2 times higher than that of disease-resistant varieties. New varieties such as 'Sunshine Rose' and 'Xiahei' promoted in recent years have significantly improved their disease resistance through genetic modification.
Comprehensive Control Technology System
Establish a 'Soil Testing - Variety Selection - Cultivation' integrated prevention and control mechanism: test the soil pH value before germination every year, apply sulfur powder to adjust it to 6.0-6.5; select disease-resistant rootstocks such as SO4, 5BB; adopt rain-sheltered cultivation to reduce humidity. In combination with foliar application of amino acid leaf fertilizer, the incidence rate can be reduced by 68%.
Through scientific diagnosis, precise treatment, and ecological regulation, the spread of grape yellow leaf disease can be effectively curbed, ensuring the healthy development of the grape industry.