The difference between Drug damage and Fertilizer damage of Rhododendron

Rhododendron has the same characteristics and different performance in drug damage and fertilizer damage. The similarity is that the leaves will wither and fall off in a short time, but the plaque will not expand slowly and the pathogen will not appear on it.

The difference between drug damage and fertilizer damage is shown in that azaleas are sensitive to certain or certain pesticides. For example, after spraying certain pesticides, the parts stained with the liquid in the leaves turn yellow, withered and fall off within a few days. Seriously affect the growth of the plant, but will not hurt the root system, generally not easy to lead to the death of the whole plant. Moreover, the time from the occurrence of drug damage spots to leaf shedding is longer than that of fertilizer damage (note that there are exceptions, such as plum blossoms will lose all their leaves within 1 to 2 days after spraying liquid such as dimethoate). Because it is an acidic flower, strong alkaline pesticides have obvious side effects on it. In addition, when azaleas use pesticides, first, the concentration should be low, and the second is to avoid high-temperature season around noon to prevent drug damage. Azaleas like fertilizer, but can not tolerate fertilizer, let alone alkaline fertilizer, otherwise it is easy to cause fertilizer damage to roots and leaves. For example, after mistakenly applying raw fertilizer, thick fertilizer, big fertilizer and base fertilizer, it is easy to lead to reverse osmosis in the delicate hairy fibrous root cells of rhododendron, which causes its tender roots to wither and die after losing water, and can cause scorched leaves within 1 to 2 days, or even fall off all of them. in serious cases, the whole plant dies. If the concentration of fertilizer solution is too high, timely immersion leaching and rescue will not die, but it will seriously hurt the "vitality" of the plant, and it will be difficult to recover in a short period of time. For this reason, cuckoo fertilizer should be applied frequently and blindly. The concentration of general organic fertilizer is about 10%, that is, 10 times the water. The concentration of chemical fertilizer is about 0.3%, which is used to irrigate the roots, and the concentration of foliar topdressing is about 0.1%. In addition, whether Yingshanhong or western rhododendron is also sensitive to compound potassium dihydrogen phosphate containing some trace elements, it should not be used to spray leaves, otherwise it will easily lead to scorched leaves and withered twigs, which will also seriously affect their growth or survival. During the high temperature season from July to August, the growth of rhododendron was stagnant, so fertilization should be stopped. In late autumn and early winter, the species of plants that enter the dormant state should stop fertilizing in winter. In general, the next morning after fertilization, water should be watered once to dissolve the fertilizer in the soil to facilitate its root absorption.

The situation of fertilizer and drug damage in other flowers is basically the same as that of rhododendron, but pesticides that are sensitive to some flowers must be avoided, such as pomegranate and cruciferous flowers, plum, peach, cherry blossom, pomegranate, apricot, orange, chrysanthemum, coral flower, golden bract, shrimp flower, golden vein flower, golden vein single flower, reticulate grass, etc., avoid dimethoate and omethoate, cedar avoid quick culling. Plum, peach, cherry blossom and other trichlorfon, pear, persimmon, peach, plum bogey sulfur mixture, orange, peach, apricot, pear, plum, persimmon Bordeaux, cherry, candle bogey malathion, wine bottle orchid methamidophos, peach blossom sensitive to triadimefon, plum blossom allergic to monocrotophos and carbofuran. For the above-mentioned species of flowers and trees, care must be taken when using pesticides: first, avoid using them as far as possible, second, it is best to use them in the defoliation period, and third, reduce the concentration and control the drug damage to a minimum.