Tomato yellow top has "four causes"
(1) Iron deficiency The absolute iron content of soil is low, or more fertilizer, more potassium, more ammonia, more calcium, easily lead to iron deficiency; the temperature is too low when planting, so that the absorption of iron by plants is hindered. (2) Anoxic soil or nutrient solution is deficient in oxygen, nitric acid is oxidized to nitrous acid, or soil is seriously acidified, and the conversion from nitrous acid to nitric acid is stopped. Poisoning caused by nitrous acid accumulation also causes yellowing of the top tender leaves. (3) Injury of residual herbicides If the herbicide Simazine is used in the previous crop, the top leaves of the herbicide will also be yellowed. (4) Phytotoxicity caused by plastic nutrients The raw materials for plastic nutrients produced by some manufacturers are not standardized, and the chemical ingredients harmful to tomatoes may be mixed in the recycled materials, which may cause yellowing of the top leaves. Personal Care,Hair Conditioner,Body Wash Shower Gel,Moisturizing Shower Gel Wuxi Keni Daily Cosmetics Co.,Ltd , https://www.kenidaily.com