Growth, yield and preliminary selection of seedling guavas in Queensland

Abstract

Five guava seedlines of Hawaiian origin, namely GA9-37, GA12-1 6, GA10-48, GA11-56 and GA9-39 were yield tested in coastal sub-tropical south-eastern Queensland. The work demonstrated that seedling guavas produce attractive yields comparable with overseas countries. First crop mean yields were 30.72 kg/tree after 18 months in the field, demonstrating the precocious bearing of the guava. Yields for second and third cropping years were 45.6 and 77.9 kg/tree. These yields equate to 24.7, 37.2 and 61.5 tonnes ha-1 at a planting density of 805 trees ha-1. Third crop yields give the attractive gross returns of around $15,000 ha-1, at current prices paid by processors in Queensland. No differences were found between seedlines in annual yields, accumulated crop yields, fruit Number/tree, annual yield per unit cross sectional area of butt (an index of fruitfulness) and accumulated yield per unit cross sectional area of butt. Within seedline, variability masked differential response and these aspects are discussed. Fruit yields and relative increase in butt cross sectional area of butt varied with cropping year. Fruit. number per tree and yield per unit cross sectional area of butt varied with years, as did fruit number per kg (an index of fruit size). The latter also varied with seedlines. These effects were attributed to water rationing in spring of the second crop year. Preliminary selection based on fruit quality aspects of individuals identified four individuals which are undergoing detailed processing assessment, namely GA9-39R1T2, GA11-56T7, GA11-56R5T2 and GA1 1-56R5T1. Two further individuals were selected for fresh fruit market testing, namely GA11-56T3 and GA11 -56R1T1. We believe that market development rather than horticultural problems to be overcome will dictate the success of the guava as a crop for Australia, since the guava is comparatively easy to grow and manage.