Detailed Explanation of Key Orchard Management Techniques for Rosa roxburghii (Chestnut Rose) Cultivation

Fertilization

Apply quick-acting fertilizer 7 to 10 days before the spring, summer and autumn shoots sprout, focusing on nitrogen fertilizer to promote shoot growth and leaf development. The amount of topdressing in the 2nd and 3rd years should increase year by year. Before the summer and autumn shoots sprout, apply 0.05 to 0.1 kg urea or 5 kg clear manure water per plant as topdressing. After the shoots and leaves of each season have sprouted and taken shape, spray potassium dihydrogen phosphate or other high-efficiency compound fertilizer on the foliage to promote maturity of the shoots and leaves. Starting from the outer edge of the planting hole, dig deep and expand the hole year by year combined with applying green manure, improve the soil, and use the orchard to maintain the orchard, ensuring normal growth of the fruit trees.

15 to 20 days before flowering, apply 0.1 to 0.2 kg urea or 15 to 20 kg clear manure water per mature fruiting tree as topdressing to ensure normal growth and development of flower buds and leaf buds. After flower drop, promptly spray 0.5% urea solution to supplement tree nutrients and promote normal development of young fruit. From late June to early July, spray 0.5% potassium dihydrogen phosphate on the foliage of each plant and apply 0.25 kg urea or 30 kg manure water to the root soil of each plant. Depending on the nutritional status of the tree, spray 0.5% urea solution on the foliage again, once every 7 to 10 days, for 2 to 3 consecutive times, to promote fruit enlargement and improve yield and quality. Apply sufficient base fertilizer and improve the soil to lay the foundation for extending the full fruiting period and for a bumper and stable harvest the following year.

Diseases

The main pests and diseases of Rosa roxburghii (Chestnut Rose) include the pear fruit moth and peach fruit moth, rose long-tubed aphid, rose white scale, and powdery mildew. For control of the pear fruit moth, peach fruit moth and aphids, you may choose 40% dimethoate emulsion at 1500 times dilution, 80% dichlorvos at 2000 times dilution, or fenvalerate at 2000 times dilution. For rose white scale, spray 5-degree lime sulfur mixture in winter. For powdery mildew, use 70% thiophanate-methyl wettable powder at 800 to 1000 times dilution, or spray 155 triadimefon wettable powder at 1000 to 1500 times dilution. For pest and disease control of Rosa roxburghii (Chestnut Rose), attention should be paid to autumn orchard cleanup by pruning diseased and insect-damaged dead branches and diseased and insect-damaged fruit, plowing the soil, and spraying chemicals to sterilize and kill insects.

Irrigation

The root system of Rosa roxburghii (Chestnut Rose) is relatively shallow and its drought resistance is relatively weak. Water conservancy facility construction must be strengthened. In the dry season, divert water for irrigation or cover the tree disk to keep the soil moist.

Pruning

The buds of Rosa roxburghii (Chestnut Rose) have strong sprouting and branching ability. The crown is short and the branches and leaves are luxuriant, with no obvious apical dominance or vertical dominance. Therefore, Rosa roxburghii (Chestnut Rose) should not be forcibly shaped and pruned, and natural growth is preferable. When pruning, only diseased and insect-damaged branches, dead branches and senescent branches should be cut off. For senescent branch groups, retraction should be used to promote vigorous branches. For mature trees, focus should be placed on regulating the relationship between growth and fruiting, so that Rosa roxburghii (Chestnut Rose) can achieve the goal of stable and high yield.