Foliar fertilization technique of Orchid

Foliar fertilization of orchid has the characteristics of less fertilizer, fast absorption and strong pertinence, which plays a very important role in preventing and controlling element deficiency and enhancing the growth and disease resistance and cold resistance of orchid plants. So how much do you know about the specific methods of foliar topdressing of orchids? This paper describes the techniques of foliar fertilization in orchids.

1. Types of fertilizer spraying

The growth of orchids, like other plants, must first meet the needs of nitrogen, phosphorus and potassium, but trace elements such as calcium, iron, zinc, magnesium, copper, boron and molybdenum are also essential. Fertilizer commonly used for foliar spraying of orchids, including urea, ammonium sulfate and ammonium nitrate; phosphorus containing calcium superphosphate, potassium phosphate and potassium dihydrogen phosphate; potassium nitrate and potassium chloride containing potassium; calcium superphosphate; ferrous sulfate containing iron; zinc sulfate containing zinc; magnesium sulfate containing magnesium; copper sulfate containing copper; borax and boric acid containing boron; molybdic acid containing molybdenum.

two。 Fertilizer concentration

Foliar fertilization for orchids must be carried out according to a certain proportion, so as to ensure that there should be good fertilizer effect and not suffer fertilizer damage. The concentration of spraying fertilizer varies with different fertilizers, generally: urea 0.2%, potassium dihydrogen phosphate 0.3%, potassium sulfate and potassium nitrate compound fertilizer 0.1%, calcium superphosphate 0.5%, magnesium sulfate 0.5%, ferrous sulfate 0.5%, zinc sulfate 0.1%, copper sulfate 0.2%, borax, boric acid 0.3%, molybdic acid 0.1%. In addition, fertilizers such as Yiduo, Yuanshuo, Shida, Orchid King and Spencer should be prepared and applied according to the product instructions.

3. Spraying site

In order to spray fertilizer on the leaves of orchids, the emphasis should be on the north of the leaves. This is because the front of the leaf is covered with a bright stratum corneum, and the fat liquid is not easy to enter. On the other hand, there is no stratum corneum on the back, and there are many stomata, and the fat liquid is easy to infiltrate and absorb. But when spraying, be sure to spray the whole plant, that is, all parts except the orchid root: leaf surface, petiole, leaf pants and bulbs on the soil surface. The orchid plant placed on the ground should be placed on the side of the orchid basin and turned for a week when spraying fertilizer, so that the fertilizer liquid can cover all aspects and promote the balanced growth of the orchid plant.

4. Timing of fertilizer spraying

Spraying fertilizer on the leaves of orchids is usually applied once in 7-10 days and 2-3 times in succession during the period of new buds and new roots. From flowering to flowering, apply once every half a month or so. Apply 1-2 times per month in other growth periods, apply more nitrogen and potassium fertilizer in vegetative growth period, and apply more phosphorus and potassium fertilizer in reproductive growth period. The time of foliar spraying depends on the weather, temperature and humidity. When the temperature is between 18 and 25 ℃, the stomata of orchid leaves are fully opened, and the effect of fertilizer spraying is the best. The temperature is below 15 ℃. Due to the low temperature, the stomata of the leaves are closed or rarely opened, and the fertilizer liquid is not easy to absorb. When the temperature is above 30 ℃, the leaves are baked because of the high temperature, and fertilizer spraying will cause fertilizer damage. When the air humidity is high, the fertilizer liquid stays on the leaves for a long time and absorbs the most nutrients. The best time to spray fertilizer is in sunny or cloudy days when there is no wind, especially in the early morning and evening. At the same time, we must also pay attention to do not apply to the severe cold, heat, rainy days, noon and flowering.