Plums were watered several months before flowering.

Plum tree is a very special drupe tree. At present, the main varieties suitable for protected cultivation in China are: American plum, Li Hongmei, Jin Hongliang, Dashi Zaosheng, Zaomeili, Molteni, and Qiuhong is also used as pollination tree species. According to the current production situation, the author briefly summarizes the technical measures widely used in the current production as follows:

I. Planting techniques

1. Shallow planting. When planting, it should be planted shallowly, and then covered with soil and ridged.

2. Ridge cultivation. When ridging, organic fertilizer is added to the soil, and the ridge is about 30 cm high and 80 cm wide. Plant plum trees on the ridge of the field. 3. Bag planting. Fill plastic woven bags with matrix soil, plant them into saplings, and bury the bags in the soil in the shed.

2. Plastic trimming technology.

Protected cultivation of plum should not only make full and reasonable use of space, but also ensure ventilation and light transmission. When shaping and pruning, it is not appropriate to emphasize the tree shape unilaterally, but to give priority to light pruning. First, we should get rid of non-flowering vegetative branches, pests and diseases branches and over-dense branches. Strive for: firm skeleton, reasonable structure, compact branching group and uniform size. In the pruning method, priority should be given to "more thinning in summer and less pruning in winter" to prevent the crown from closing, improve the ventilation and light transmission conditions in the inner room, reduce flower and fruit drop, promote flower bud differentiation and improve fruit quality.

Third, the growing season management technology.

1. Fertilizer and water management. When the new shoots grow to 15-20 cm, apply 25 grams of urea to each plant underground, and water them in time after topdressing. Spraying 0.3% urea mixed with 0.3% potassium dihydrogen phosphate on the leaves of trees every 10 day. After mid-July, 25 grams of potassium dihydrogen phosphate was topdressing underground, combined with foliar topdressing, and 0.3% potassium dihydrogen phosphate was sprayed every 10 day until the leaves fell off. Pay attention to drainage in rainy season, and generally do not water it unless it is particularly dry.

2. Choose your heart. In the middle and late May, 4-6 new shoots with suitable growth and angle were selected for key culture. The rest of the buds were erased. When the new shoot grows to about 30 cm, the top is removed 10- 15 cm to promote secondary branches. Increase the number of branches by continuous coring.

3. Pull the branches. In mid-July, on the basis of coring, 3-4 permanent branches were selected and drawn at an angle of 60-70, and the remaining branches were drawn at an angle of 80 as auxiliary branches. The upright and vigorous branches on the permanent branches should be twisted flat in time, and the branches that are too dense should be thinned out.

4. Paclobutrazol promotes flowers. After pruning, spraying 300 times of paclobutrazol 15% and 350 times of potassium dihydrogen phosphate once each. Spray twice every 15-20 days, and the concentration is 150-200 times. After two times of chemical control, it can effectively inhibit the growth of new shoots and promote flower bud differentiation.

5. Flower and fruit management. Pollination at flowering stage. First, artificial pollination, second, releasing bees in flowering period, and it is appropriate to put bees 1-2 boxes in each shed; Spraying "Su Le Boron" 1500 times in bud stage and young fruit stage; When the new tip grows to 25 cm, the core is removed; According to the growth situation, 300 times solution of 15% paclobutrazol can be sprayed once after flowering/0/5 days to control the vigorous growth of new shoots and improve the fruit setting rate; In order to produce high-quality fruits, it is necessary to thin and set fruits. Generally, there are 3-4 long fruit branches, 1-2 short fruit branches. During fruit expansion, foliar fertilization is carried out; High-quality fertilizer and micro-fertilizer can be sprayed 20 days before harvest to improve fruit quality. For more technology, please refer to fruit.org/jishu/list/4410/,the column of plum planting technology in China.