博文

目前显示的是 七月 5, 2018的博文

What’s difference between early blight and late blight?

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Early blight and late blight are important diseases on solanaceous vegetables.Although the names of the two diseases are only one word difference,some vegetable farmers do not know exactly about early blight and late blight.Some people even think that the two diseases are only happening time different. There are many problems in the prevention and treatment of diseases.Especially in the selection and use of chemical fungicide,blind drug use not only does not play a role in disease prevention,but delays the best prevention and control time,leading to serious diseases.
What’s difference between early blight and late blight?
Early blight mainly affects the stems,leaves,and fruits of vegetables,and is most susceptible to disease at the branches of leaves and stems.At the seedling stage,the base of the stem of the seedlings is dark brown lesions,slightly sunken,and has a ring pattern.The onset of adulthood generally develops from the lower leaves to the upper part.The leaves are infected,the …

What’s symptom of grape magnesium deficiency?

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What’s symptom of grape magnesium deficiency?The leaves are chlorotic.Because magnesium can be transferred to young parts in plants,the top leaves are asymptomatic. Initially starting from the base blade,the leaf edge turns yellow first,the leaves are water-stained,and the yellow veins are severe.
General reasons 1.The soil is mostly acidic,the pH value is too low,the magnesium leaching is serious,the release of magnesium is obviously inhibited,and the average content of exchangeable magnesium in the soil is lower than the critical level,and the magnesium deficiency is serious. 2.Grapes are potassium-producing crops,but excessive potassium inhibits the absorption of magnesium by the roots of the grapes and transports magnesium ions to the above-ground parts,causing magnesium deficiency. 3.Magnesium and calcium,ammonium ions also have antagonistic effects,therefore,the soil calcium content is too high or the application of calcium and nitrogen fertilizers will reduce the absorption of m…