Abstract:
Objective Effects of bagging with paper pouches of different light-transmitting property on fruit color and carotenoids composition of red-flesh Banjintao peaches were investigated.
Method Pouches made of yellow-colored, monolayer paper providing 50% light-transmittance and those laminated with a black interior layer to block the sunlight transmission were used to bag the fruits on the peach trees starting 40 d after full bloom. For control, no bagging was applied on the fruits (CK). Chromatic aberration and carotenoid compositions of the peach sarcocarp were measured at 71, 82, 90, and 95 d after full bloom.
Result The bagging with 50% light-transmitting pouches on the peaches increased Chromatism B of the sarcocarp initially and followed by a decline, did not affect Chromatism C or H, and decreased Chromatism A 82 d after full bloom. The 2-layer pouches, which allowed no light exposure for the fruits, induced no effect on Chromatism A and C, while reduced Chromatism B and H on the ripened peaches. On the other hand, Chromatism L of the sarcocarp rose upon ripening with or without the bagging. The treatments exerted no significant effect on the bagged peaches on the total carotenoids, β-cryptoxanthin or α-carotene in the sarcocarp either. But, as the fruit was ripening, the bagging caused a reduction in the sarcocarp on β-carotene and significantly increased zeaxanthins under 50% light-transmission, as well as, on xanthophylls when the fruits were not exposed to sunlight.
Conclusion In field practice, it was possible to use 50% light-transmitting pouches 40d after full bloom to bag the fruits on Banjintao peach trees to encourage the production of zeaxanthins, or to apply the 2-layer, no-light-transmission pouches to boost the content of xanthophylls in the sarcocarp.