(FROM THE NET) Manganese and zinc deficiencies are the most common ONION problem that causes tops to prematurely bend over OR become disfigured....Tops falling over prior to the bulb reaching maturity can result in decreased yields Young plants are particularly sensitive to Zn deficiency..... Problems are more common on high pH or calcareous soils or during cold, wet weather.... I suggested adding poultry manure (chicken manure) -- poultry manure tends to be high in Zinc, in a well balanced way. .Zinc also exits naturally in rocks. The amount of zinc present in the soil depends on the parent materials of that soil. Sandy and highly leached acid soils generally have low plant available zinc. Cool soil temperatures in early spring can intensify the need for zinc. Root growth is also stunted by cool temperatures and reduces the plant’s ability to find new sources of zinc in the soil profile. Also note: -onions and other alliums need more phosphorus and potassium than most other vegetables. They also need more copper, manganese, zinc, and molybdenum. Also please be aware that : There is a known relationship between phosphorus and zinc in the soil. Excessive application of phosphate fertilizers can caused zinc deficiencies. A phosphorus-induced zinc deficiency is a concern and may occur only if very high rates of phosphate fertilizer (more than 200 lb P2O5/acre) are used and the soil has zinc levels is in the range between Low and Very Low.

- Celeste Archer