Researchers from various countries have proposed using dry matter at harvest as a worldwide quality index for Hayward kiwifruit, because it includes both soluble (sugars and acids) and insoluble (structural carbohydrates and starch) solids and doesn't change during post-harvest handling. Our consumer tests in 1999 and 2008 indicated that dry matter and ripe titratable acidity are related to in-store consumer acceptance of kiwifruit. In most California seasons, when ripe titratable acidity was less than 1.2%, only a dry matter greater than or equal to 15.1% was required for consumer acceptability. Our 6-year quality attribute survey of California kiwifruit at harvest and from cold storage demonstrated that dry matter and ripe soluble solids concentration were highly variable among vineyards and seasons, but ripe titratable acidity values varied more among seasons than between vineyards. Our results provide strong evidence that dry matter would be a reliable quality index candidate for California kiwifruit, especially if ripe titratable acidity were factored in.

Slow-release pheromone tech-nology can successfully control oriental fruit moth and peach twig borer while eliminating in-season insecticide sprays in cling peaches. In conjunction with a demon-stration program, we compared mating disruption for these two pests with standard grower pest-control methods in the Sacramento and San Joaquin valleys, and monitored for pest damage, yield and grower costs. While the mating-disruption program was effective in controlling the targeted pests, costs were higher and growers preferred a partial disruption program that included some supplemental late-season insecticide sprays. Subsequently, we developed monitoring methods to determine the need for supple-mental sprays. This partial mating-disruption program still costs about $60 more per acre than a standard spray program. Predicting efficacy and determining the need for supplement sprays is also more difficult with the partial program than with the pheromone-based control program.