Uniformity of production of spring cabbage in New Zealand

Abstract

Spring cabbage, sown during March and April, displayed variability in yield when harvested weekly from areas of equal size transplanted from each autumn sowing. The proportion of the total area which is needed to be transplanted from each sowing to give the least variation in weekly yield was determined using quadratic programming analysis. Weekly yields were then calculated to be even more uniform if harvesting was carried out between first maturity and overmaturity rather than only at first maturity. Calculated yields using the proportions from 1 year's observations and the means of between 2 and 4 years' observations were nearly the same. The proportions needing to be planted from a series of sowings to give the least variation in weekly yield can therefore be determined reasonably accurately in 1 year.

Keywords:

• spring cabbage
• production policies
• quadratic programming
• harvesting
• timing
• vegetable crops