In Western Australia, Carnarvon is the main source of supply of capsicums during the southern winter months of June to August. The quality and quantity of capsicums reaching Perth market, however, are variable and the prices are very volatile. The prices are generally higher in November-December when Carnarvon capsicums are prone to sunburn and wind damage.

A desktop study and a grower survey on the marketing potential and capsicums were carried out. This found the need for suitable varieties that meet the quality specifications and a production system that will offer protection against environmental vagaries. Varieties that produce uniform, blocky fruit are preferred by the market. Three variety x time of planting trials were conducted in Carnarvon to identify capsicum varieties suitable for early (April/May), mid (June/July), and late (August/September) plantings. Early planting in April gave the highest yield followed by mid and late season plantings. The average yields were 41,22, and 14 t/ha, respectively, of early, mid, and late season crops.

A simple structure that offered wind protection and reduced sunlight by 30% extended the cropping season late into the summer. Without this protection sunburn was high (70%) and marketability was low at 22%. Premium grade fruit, however, was low at 10-15% due to blossom end rot, powdery mildew, and soil-borne diseases under the protected system.

To compete in export markets, the proportion of premium grade fruit has to be increased. This will allow Carnarvon growers to supply capsicums to niche markets is SE Asia, Taiwan, and Mauritius. Further study on different protective structures and their economics is needed.

This project has been funded by Hort Innovation, using the research and development levies listed below and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

• Vegetable Fund