Fertilization should be adjusted flexibly according to the different growth stages of the crop

Depending on the timing of fertilizing the orchid plants, the fertilizers can be divided into: the pre-sprouting sprout-promoting fertilizer, the root-promoting and flower-forcing fertilizer during the leaf bud dormancy-breaking stage, the growth-promoting fertilizer during the leaf-unfolding stage, the ripening and cold-resistance fertilizer in late autumn, the dowry fertilizer half a month before division and repotting, the awakening fertilizer in warm spring, the root-promoting fertilizer when roots are few, and the postpartum fertilizer after flowering, etc. (1) Awakening fertilizer This is the fertilizer applied to break dormancy, promote early sprouting, and strive to produce one more flush of shoots per year. When the daytime temperature is not lower than 18°C and the nighttime temperature is not lower than 3°C, the awakening fertilizer can be applied. A 0.1% potassium nitrate compound fertilizer solution, a 0.02% ammonium bicarbonate solution, or a 0.1% decomposed human urine solution is often chosen and poured once; 10 days later, a 500-fold dilution of Lan Jun Wang is poured once more. Every 5 days, in the evening, foliar fertilization is carried out once, spraying a 500-fold dilution of "Shida", or a 1000-fold dilution of "Huabao" No. 4, and mixing in a 2000-fold urea solution and a 250-fold edible rice vinegar solution. (2) Sprout-promoting fertilizer About 15 days after applying the awakening fertilizer, pour once more the same fertilizer solution as the awakening fertilizer, or apply a 500-fold "Lan Jun Wang" solution alone once. The application of foliar fertilizer is the same as that of the awakening fertilizer. (3) Root-promoting and flower-forcing fertilizer When the new shoots emerge 3-5 cm above the substrate surface, there is a period of paused elongation. At this time, the new shoots are about to grow roots, the mother plant temporarily half-stops supplying nutrients to the new shoots, and shifts into reproductive growth, beginning to form flower primordia and differentiate flower buds, requiring nutrition low in nitrogen and rich in phosphorus, potassium, and boron. Therefore, a 1500-fold dilution of monopotassium phosphate should be poured once a week, and every 5 days a 1000-fold solution of "Huabao" No. 3 mixed with an equal amount of boron should be sprayed outside the roots once. (4) Growth-promoting fertilizer When the new shoots have grown 2 cm-long roots, the differentiation of flower buds has also been settled. At this time, the new shoots urgently need a full-nutrient fertilizer. A 0.15% potassium nitrate compound fertilizer, or a 1000-fold dilution of composted organic liquid fertilizer, is often applied once every 15-20 days. Once a week, spray on the leaves "Huabao" No. 5, or a 1000-1500-fold dilution of American-made Gaole and Lüfenwei No. 2 (not to be used on variegated orchids). Swiss-made Aishi brand foliar fertilizer, Fujian Province-produced Gaochangling, plant biostimulant (usable on variegated orchids), etc. For variegated orchids, crystal-art orchids, and picture-pattern variegated orchids, it is not advisable to apply foliar fertilizers with high nitrogen content and containing magnesium. When pouring liquid fertilizer, the concentration should also be reduced by half. Foliar fertilizers with low or no nitrogen content include Zhiquan comprehensive mineral biostimulant, monopotassium phosphate, Suzi, etc. (5) Flower-promoting fertilizer Apply five times 15-20 days before the flowering period. For root application, a 500-fold dilution of composted organic liquid fertilizer can be chosen, or 0.1% potassium nitrate compound fertilizer, adding a 1500-fold monopotassium phosphate. For foliar topdressing, "Huabao" No. 3, a 1500-fold monopotassium phosphate solution plus 0.2% borax, etc., can be chosen and sprayed alternately. (6) Ripening and cold-resistance fertilizer Before overwintering, the orchid plants should be promoted to develop and mature their leaves early, greatly reducing the free water in the plant body, increasing the bound water that does not freeze, raising the sugar content, and increasing cellulose, so as to enhance cold resistance. Therefore, starting in mid-autumn, nitrogen supply should be stopped, and phosphorus and potassium fertilizers should be applied as topdressing. The method is to pour and spray a 1000-fold dilution of monopotassium phosphate two or three times. (7) Dowry fertilizer Since orchid plants have just been divided and repotted and have not yet grown new roots, it is not advisable to fertilize them. Therefore, in order to improve the orchid plants' ability to recover from wounds, a full-nutrient liquid fertilizer must be applied about half a month before division and repotting. For the specific implementation method, refer to the application of the growth-promoting fertilizer. (8) Postpartum fertilizer The flowering of orchid plants consumes a great deal, and only timely supplementation can prevent it from affecting overwintering, premature aging, and the next year's sprouting. A 500-fold dilution of composted fertilizer or 0.2% potassium nitrate compound fertilizer is often chosen and poured once, and plant biostimulant and compound trace elements, etc., are sprayed on the leaves two or three times. (9) Root-promoting fertilizer Wild-collected seedlings, introduced seedlings, diseased and weak seedlings, and repotted seedlings may all have few or no roots, so root promotion is needed. For newly potted orchid seedlings, since the root wounds have not yet formed callus and new roots have not grown out, fertilizing at this time easily causes the wounds to rot, leading to new root rot. Therefore, ordinary fertilizers should not be applied; only when watering can a 1500-fold dilution of American-made Cugensheng or a 500-fold dilution of Lan Jun Wang be applied along with the water. In addition, every 3-5 days, in the evening, the diluted solution of the above root-promoting agents can be sprayed. (Xu Dongsheng)