The effect of shading and leaf flushing on the ripening pattern of durians

Abstract

Uneven fruit ripening is often observed in durians (Durio zibethinus Murray), but its cause is unknown. In order to understand the development of this disorder, 'Mon-Thong' durians from leaf flushing and shaded trees were studied. It was found that durians normally accumulated photosynthate and ripened, by converting starch to sugar, unevenly in the direction from the stylar end to the stem end; however, in terms of softening, uneven ripening was found to be non-directional. The fruit from leaf flushing trees was found to have a higher uneven fruit softening score, as well as higher variation in pulp firmness but not soluble solids content, than those harvested from control trees. In addition, fruit from 50% shaded trees, 99-105 days after full bloom (DAF), was compared to fruit from non-shaded trees. Higher uneven fruit softening was found in durians from shaded trees. When durians were harvested again one week after removal of shading, they had similar ripening characteristics to those from control trees. It was shown that factors that limit fruit development and its maturity positively enhance the non-directional softening pattern. It was also found that treating durians with a high concentration of ethephon could not alleviate this phenomenon. JSHS © 2011.