(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) The herbicides of the remaining herbicides, if used before the herbicide Simazine, the top leaves will be yellow. (4) Phytotoxicity caused by plastic nutrient pods. The raw materials for plastic nutrients produced by some manufacturers are not standardized. The chemical ingredients that are harmful to tomatoes are mixed in the recycled materials, which may cause yellowing of the top leaves.
Raw Sunflower Seeds,Plain Sunflower Seeds,Unroasted Sunflower Seeds,Raw Sunflower
Wuyuan county dafeng oil food co.,ltd , https://www.dafengfood.com.cn