Key Points for Diagnosing and Treating Nutrient Deficiencies in Flowers and Preparing Seeds Before Sowing

Nitrogen deficiency: the plant is thin and weak, with slender, elongated, hard stems, and small leaves and flowers. Leaf color gradually fades from deep green to pale from the old leaves to the new leaves, then develops a red-purple hue, until it turns yellow and drops off; in severe cases the whole plant loses its green color.

Treatment method: Apply more decomposed human manure and urine, cake fertilizer, barnyard manure, or fertilizers such as ammonium sulfate, urea, and ammonium nitrate. Phosphorus deficiency: the leaves turn from dark green to copper-purple, and the veins (especially the petioles) become yellowish with a purple tinge. Flower bud formation becomes difficult, flowering is small, sparse, and pale, leading to poor fruit development and even early withering and dropping.

Treatment method: Apply more bone meal, fish meal, poultry manure, or superphosphate, ammonium phosphate, and potassium phosphate (a phosphorus-potassium compound fertilizer); generally use about a 0.10% aqueous solution for foliar topdressing.

Potassium deficiency: the plant is short and small, and the stems are soft and prone to lodging. The leaves often become wrinkled, and dark brown spots appear on the old leaves starting from the leaf tips along the leaf margins; the area around the leaf turns yellow, while the middle and the veins remain green.

Treatment method: Apply more plant ash, a 1%-2% potassium chloride aqueous solution (avoid for bulb and tuberous-root flowers), and a 0.30%-0.50% potassium nitrate aqueous solution for foliar topdressing; inorganic fertilizers such as potassium phosphate can also be used.

Calcium deficiency: the young leaves are green and wrinkled, the leaf margins curl upward and have white stripes, flowering is hindered, and the new leaves are difficult to unfold or become diseased and distorted. Treatment method: half a month before sowing or potting, apply an appropriate amount of calcium chloride to the soil, which can increase calcium and disinfect (avoid for acid-loving flowers); calcium nitrate can also be used as a topdressing.

Magnesium deficiency: the plant grows poorly. The old leaves gradually lose green and turn white from the leaf margins to the center, from bottom to top, and spots of various colors appear on the veins, and finally the whole leaf turns yellow.

Treatment method: Spray continuously with a 0.20%-0.40% magnesium sulfate aqueous solution 3-4 times, with an interval of 7-10 days each time. For soil severely deficient in magnesium, use 5-10 kg of magnesium sulfate per mu, mixing it into the base fertilizer in autumn or winter and applying it to the soil.

Sulfur deficiency: the young leaves begin to yellow from the veins, and eventually the whole leaf turns yellow, and the root system develops abnormally.

Iron deficiency: yellowing from the young leaves to the old leaves. For the treatment of sulfur deficiency and iron deficiency, spray with a 0.30% ferrous sulfate aqueous solution, 3 times continuously, with an interval of 1 week each time; the mist droplets must be fine and even when spraying. At the same time, a 0.20% urea-iron aqueous solution can be used for foliar topdressing.