Diagnosis and Correction of Nutrient Deficiency in Orchids

Contents:

    OrchidsWhen an orchid lacks a certain nutrient, it will show signs on the plant. Based on these signs, the nutrient deficiency can be diagnosed and corresponding measures taken to correct it.

    ① Nitrogen deficiency. It shows as new leaves being shorter and narrower than old leaves and thin in texture, with pale yellow leaf color and lack of luster. You can water the roots with a 500-fold dilution of potassium sulfate compound fertilizer or potassium nitrate compound fertilizer, and spray the leaf surfaces and undersides in the evening with a 0.2% urea solution. Spray once every three to five days, for 3 consecutive sprays, and it can be corrected.

    ② Phosphorus deficiency. It shows as leaf buds growing slowly, roots being slow to emerge, and leaf margins curling slightly backward. You can water the roots with a 2% superphosphate extract, or a 3%-5% bone meal solution, or an 800-fold dilution of monopotassium phosphate, once every 10 days, for 2 consecutive waterings; and spray the leaf surfaces and undersides in the evening with a 600-fold dilution of monopotassium phosphate, or a 1000-fold dilution of Huabao No. 3, once every three to five days, for 3 consecutive sprays, and it can be corrected.

    ③ Magnesium deficiency. It shows as old leaves turning yellow; the leaf tips and margins of middle-aged leaves turning yellow and curling toward the leaf surface (commonly known as "gongluo margin"). You can spray the leaves in the evening with a 0.5% magnesium sulfate solution, once every three to five days, for three to five consecutive sprays, and it can be corrected.

    ④ Potassium deficiency. It shows as leaf margins and leaf tips turning yellow (old leaves first, then new leaves), then turning brown; the midrib and lateral veins of leaves being somewhat thin; leaf texture being soft and prone to bending and drooping; if exposed to strong light and low temperature, new leaves show slight dehydration. You can first water the roots and spray the leaves with a 0.5% potassium sulfate solution, or scatter wood ash.

    ⑤ Manganese deficiency. It shows as sunburn-like spots appearing even with proper shading, with spots within the spots, flower buds not developing; leaves shriveling, losing green color, and lacking luster. Neutral, calcareous and sandy soils are more prone to manganese deficiency symptoms. Spraying the leaves with a 0.3% manganese sulfate solution 3 times can correct it.

    ⑥ Calcium deficiency. It shows as leaf tips being hook-shaped (except in varieties where this is a characteristic trait). It is commonly seen in plants given acidic fertilizers. You can water the roots once with a 1.0% lime solution, or apply a 3% solution of livestock calcium powder once, and it can be corrected.

    ⑦ Iron deficiency. It shows as the mesophyll of young leaves turning yellow to white, and the middle leaf veins, leaf margins and leaf tips showing scorched brown spot necrosis. You can spray the leaves with a 0.5% ferrous sulfate solution, once every 3 days, for two to three consecutive sprays, and it can be corrected.

    ⑧ Zinc deficiency. It shows as pure rust-like spots appearing in the middle section of the bottom leaves, gradually spreading toward both ends of the leaf; the petiole ring of new growth being noticeably lower than that of old leaves. You can spray the leaves with a 0.1% zinc sulfate solution, once every three to five days, for 3 consecutive sprays, and it can be corrected.

    ⑨ Copper deficiency. It shows as leaf tips losing green color, gradually turning grayish-white and spreading to the whole leaf, with growth stagnating. You can spray with a 0.2% copper sulfate solution, once every 7 days, for 2 consecutive sprays, and it can be corrected.

    ⑩ Boron deficiency. It shows as the base of young leaves being injured, the petiole ring being extremely brittle and easily broken, the number of flowers per scape being noticeably reduced, flower buds opening slowly and appearing listless when open, and the lasting period of flowers after opening being noticeably shortened. You can spray with a 0.3% borax or boric acid solution, once a week, for 3 consecutive sprays, and it can be corrected.

    ⑩ Molybdenum deficiency. It shows as new growth being noticeably dwarfed even without applying chlormequat; old leaves losing green color, becoming withered and yellow, wilting to the point of necrosis. You can spray with a 0.1% ammonium molybdate solution, once every 3 days, for 3 consecutive sprays, and it can be corrected.

    If fertilizer can be supplemented according to what the orchid plant lacks, so that the nutrient elements in the plant are relatively balanced, then the functions of each organ of the plant can be fully brought into play and coordinated, which has a very good effect on improving both yield and quality.