A study of the production of high value cauliflower crops, on a year round basis in Christchurch: A thesis submitted in partial fulfilment of the requirements for the National Diploma of Horticulture in N.Z. R.N.Z.I.H.

Abstract

A review of the literature and commercial practices in Christchurch was done to determine whether it is possible to produce high value crops of cauliflowers on a year-round basis. Four experiments, using an appropriate range of cultivars, were sown to harvest during December, February-March, June-August and September-October. Seed was sown in a glasshouse in July, and in an outdoor seedbed in October and December. A grading system was devised to classify each harvested curd into one of three grades; Grade 1, Grade II, and Reject. Generally, the recently-selected open-pollinated cultivars and the hybrids produced crops of a higher yield and better curd quality than the older established cultivars. 'Selection 174', 'Hormade' and 'supersnow 3 1/2 month Hybrid' were the best cultivars for cutting in December and February. 'Supersnow 5 1/2 month Hybrid' produced an exceptionally high yield in August when compared to either 'Ruapehu' or 'Perfected Deepheart•. A range of Walcheren-winter cultivars were used for harvest in October. ' Armado April' , 'Armada Tardo' and 'Markanta• were significantly superior to 'No 4'. The effect of reducing the leaf area for the December transplanted crop was investigated. The results using 'Selection 174' and 'Snowball X' tend to favour the practice as it produced a more uniform crop, and a higher percentage of plants produced a curd of a marketable size and quality. The study concluded that it should be possible, if the appropriate cultivar is used to produce all year round. November is the one month when a harvest is not easily attainable. Direct drilling the seed into its final position is not a common practice, but its use has been reviewed in this thesis. It could become an appropriate practice for the continuous production of mini-cauliflower sown at very high densities. The range of cultivars available to the grower is being constantly updated. It is suggested that growers should continuously assess performance of cultivars on their own property.