Planting crops at higher densities can result in greater numbers of onion bulbs, but of smaller size. Thus, it is important to manipulate sowing density to provide maximum yields of a desired bulb size. A balanced crop nutrition is important to help to reach yield potentials.
Nitrogen is one of the most important nutrients required for high onion yields. Onions are known as gross feeders and crops can remove 2-3 kg of nitrogen for every ton harvested.
Studies with calcium nitrate confirm this is one of the most effective forms for high yields.
Potassium is important for high yields in onion and garlic crops.
It is the second most utilised nutrient and uptake peaks during bulb formation and enlargement. However, care has to be taken as over-application can lead to yield reductions.
Trials have shown that zinc nutrition can improve seed germination and seed yield, both important for high yields.