1. According to the purpose and period of dressing fertilizer outside the root, choose a good type of fertilizer and suitable concentration, too thick and easy to burn the leaves, cause fertilizer damage, the effect of over-dilution fertilizer is not obvious. 2. The external conditions of top-dressing fertilizers are more stringent, such as air humidity, precipitation, temperature, and ground coverage. If the conditions are not suitable, the top dressing effect is not high. The air relative humidity during spraying is 40%～50%; if the rainfall is within 48 hours after spraying, it must be re-irrigated; the drought and hot weather should not be carried out, and the spraying should be performed at low temperature and low evaporation time. The suitable time is before 9 am or after 4 pm to maintain the moist state of the fertilizer solution, prolong the absorption time, and increase the absorption of the leaves. The extra-root fertilizer application can only be performed when the ground coverage reaches 60% or more. Special needs It can be done at any time. 3, a variety of fertilizers, pesticides mixed use, should pay special attention, must be mixed evenly can not produce precipitation. 4, strictly control the concentration of the solution and the amount of spray, to prevent the burning of leaves or the amount of less than the expected effect. 5, to focus on the new leaves, leaves the back of the spray, but the leaves must be sprayed on the positive and negative sides, in order to facilitate the mineral nutrients as soon as possible into the leaves, improve fertilizer efficiency. 6. The amount of topdressing fertilizer outside roots is small, which can only be used as an auxiliary measure, and root fertilization should still be conducted on time. Fresh Red Onions,Fresh New Crop Onion,Sweet Round Onion,Fresh Yellow Onion Laiwu Manhing Vegetables Fruits Corporation , https://www.manhingfood.com