Growing onions: Part 8

Plant population is more important than many growers may think, and getting it wrong can result in major crop problems, such as small sizes and strange shapes, says Bill Kerr.

- Bill Kerr

Plant population is linked to yield potential. In some cases, the yield potential may be the same for different populations, but the bulb size will differ. In other instances, the yield can be lower. Where the yield can be the same, choose the plant population that suits the target market; this can affect sales and price.

If the plant population is too high, many of the onions will not form a bulb and will be below marketable size. They may also develop a torpedo shape, which markets do not accept.

When this happens, you don’t only lose the unmarketable bulbs, you also compromise the yield, as the unmarketable plants use up the sunlight that would otherwise have enabled the plants alongside to make larger bulbs.