[Effects of different pruning modes on the light distribution characters and fruit yield and quality in densely planted 'Red Fuji' apple orchard].

This paper studied the effects of different pruning modes on the light distribution at different positions of canopy and the fruit yield and quality in different layers in a densely planted 'Red Fuji' apple orchard. Comparing with no pruning, both light and heavy pruning improved the light distribution in the canopy. Under light pruning, the canopy volume with a relative light intensity less than 30% occupied 14. 6% of the total, and that with a relative light intensity more than 80% accounted for 11.2%. Under heavy pruning, the two values were 12.8% and 28.8%, respectively. The fruit yield under light pruning increased in the first year, but that under heavy pruning decreased, with the fruit quality being both improved. The mean fruit mass, firmness, and soluble solid matter content decreased in the order of light pruning > heavy pruning > no pruning, the titratable acid content was in adverse, and the anthocyanin content was in the order of heavy pruning > light pruning > no pruning. From the viewpoint of fruit yield and quality, light pruning was the best modification mode for densely planted orchards.

[Effects of debagging time and picking off leaf on fruit quality of "Red Fuji" apple].

This paper studied the effects of debagging time and picking off leaves around fruits on the fruit quality and 1-year old shoots stored nutrition of "Red Fuji" apple. Properly advancing debagging time significantly increased the mean mass, anthocyanin content, and coloration area of the fruits (P < 0.05). Comparing with those of the fruits debagged on September 30, the mean mass, anthocyanin content, and coloration area of the fruits debagged on September 24 increased by 10.98%, 28.15%, and 13.44%, respectively, and the fruit firmness, soluble solid content, and titratable acidity had less differences. When the leaves within 15, 30, and 45 cm away from the fruits were wholly picked off, the light environment around the fruits improved significantly (P < 0.01), with the light intensity increased by 70%, 95%, and 115%, respectively, compared with no leaf picked off treatment. Picking off the leaves within 30-45 cm away from the fruits benefited the fruit coloration and anthocyanin accumulation. No significant effects were observed on the 1-year old shoots stored nutrition and their budding in next year among the treatments of picking off leaves. Advancing debagging time and picking off the leaves within 30-45 cm away from the fruits could improve fruit appearance and quality.

[Effects of alternative partial rootzone irrigation on peach growth, productivity, and water use efficiency].

Taking 12-year-old peach (Prunus persica L. Batsch cv. Ruiguang 5) as test material, this paper studied the effects of alternative partial rootzone irrigation (APRI) on its growth, productivity, and water use efficiency under semi-arid climate condition. The results showed that in APRI treatments, the soil water content in the wet side of peach tree decreased with increasing soil depth, while that in the dry side was in adverse, with the maximal difference appeared in 0-25 cm soil layer. In the treatments of APRI with an interval of 2 and 4 weeks, the leaf water potential at pre-dawn was lower than that in the control (sufficient irrigation), but with the time prolonged, this potential in all treatments tended to decrease, and had no significant difference in the afternoon. The peach yield in APRI treatments was 10% lower than that in the control, but the irrigation amount was reduced by 50%, and the water use efficiency was increased by 75%. APRI significantly limited the shoot growth of peach tree, but had no obvious effect on the fruit diameter.