Five steps for flower and fruit protection of navel orange

Navel orange is an excellent citrus variety cultivated all over the world because of its good quality, seedless juicy and bright color. Navel orange is rich in nutrients and contains all kinds of nutrients necessary for the human body. Navel orange contains a lot of vitamin C and carotene, which can inhibit the formation of carcinogens, soften and protect blood vessels, promote blood circulation, reduce cholesterol and blood lipids, reduce the possibility of heart disease, and prevent gallbladder disease. The navel orange has a large number of flowers, poor flower quality and serious drop of flowers and fruits. How to protect flowers and fruits is one of the important technical measures to obtain high yield of navel orange.

1. Timely pruning and smearing navel orange buds in spring should be pruned in time, cutting off top winter shoots, overgrown branches, disease and insect branches and overdense branches outside the crown, and cut off leafless globular flowers and deformed flowers. Cut short excessively long autumn shoots, leave 3-4 flowers, and keep strong and weak according to the method of "three go one, five stay two", cut off clumpy branches, erase the strong spring shoot at the top and periphery of the crown and the short and weak spring shoot that is too dense, and leave only 5-7 leaves coring or short cut over the Changchun shoot, thoroughly wipe out the late spring shoot, summer shoot and early autumn shoot.

Second, flowers and fruits are sprayed with 0.3% urea, 0.3% potassium dihydrogen phosphate and 0.2% borax (or boric acid) at bud stage, flowering stage and young fruit stage respectively. After the first physiological fruit drop (from early to mid-May) and the second physiological fruit drop (early June), spray flowers and young fruits with 50 mg / kg "92 ○" plus 0.3% imported compound fertilizer solution. In late May, the young fruit was smeared once with 250mg / kg "92 ○", 0.3% urea and 0.3% potassium dihydrogen phosphate.

Third, to prevent navel yellow fruit drop in the navel orange flower 4 / 5, combined with flowers and fruits with 70% methyl topiramate 800 times, 50 mg / kg "92 ○" mixture spray once. From late April to early May, the crown was sprayed with foliar fertilizer such as 300 times amino acid compound fertilizer or 800 times liquid of Green Fenwei 2. In the first ten days of June (after the second physiological fruit drop), spray the crown with 50mg / kg "92 ○", 0.4% imported compound fertilizer, 70% methyl topiramate 800x mixture, or smear the fruit navel with 200kg 300mg / kg "1992 ○" plus 70% methyl topiramate 800x solution, once every 10 to 15 days. From late July to mid-August, the occurrence of umbilical yellowing could be inhibited by smearing the navel of the fruit with 600-800-fold solution of xanthate.

Fourth, prevent the fruit from cracking and the fruit drop caused by fruit cracking should be irrigated and covered by the tree plate in time in the dry season. The thickness of the covered grass is 10-15 cm, and the soil around the tree plate should be ploughed and loosened before covering. 0.3% potassium dihydrogen phosphate was sprayed in the young fruit stage. From June to August, especially in the first and middle of July, potash fertilizer was applied twice. In June after the second physiological fruit drop, the navel of young fruit was smeared with 200kg 250mg / kg "92 ○", and 70% methyl topiramate 800fold solution could be added to "1992 ○" for mildly early split fruit. During the fruit expansion period from July to August, 800 times of Lufenwei No. 1 solution, or 0.3% potassium sulfate compound fertilizer solution, or 0.3% urea plus 0.2% potassium dihydrogen phosphate, 0.1% quicklime and 0.1% salt mixture were sprayed continuously for 3 times.