When should kiwifruit trees be propagated by cuttings, and how should the cuttings be taken to achieve high yields?
Kiwifruit, also known as kiwi, is a relatively common fruit in our country, and it is quite popular because it is rich in vitamin C. But to achieve high yields of kiwifruit, in addition to basic management techniques, you also need to do a good job with cuttings. So when is the best time to take cuttings from kiwifruit trees? How should the cuttings be taken to achieve high yields?
It is advisable to do this from early July to late September. This is because at this time the branches of the mother tree have stopped growing but are not yet lignified, and the survival rate after cuttings can reach more than 95%.
Cutting techniques:
1. Prepare the cutting medium
Use bricks or stones to build the edges of the cutting bed. The bed is 1.2 m wide and 0.3 m high. Spread gravel and coarse sand 0.1 m thick underneath, and place cutting medium 0.2 m thick on top. The cutting medium is made by mixing forest humus soil, sieved burnt soil, and fine sand in a ratio of 3:3:4. When mixing the cutting medium, spray it with a 1% potassium permanganate solution or disinfect it with quintozene, then seal it with plastic film for 3 to 4 days, uncover it and let it dry for 1 to 2 days, then spread it in the bed and level it.
2. Cut the cuttings
Select healthy, pest- and disease-free, semi-lignified young branches from superior middle-aged plants, and cut the cuttings segment by segment from bottom to top. Each cutting should be about 0.6 cm in diameter and 4 to 6 cm long, have 3 nodes and carry 1 to 2 axillary buds, with 1 leaf left at the upper end to facilitate photosynthesis. When cutting the cuttings, the cut should be smooth, and the upper cut should be close to the base of the axillary bud. Bundle 20 to 30 cuttings into one bunch. When bundling, the lower ends of the cuttings should be arranged neatly to make it easier to dip them in the medicinal solution.
3. Treat the cuttings
Use ABT rooting powder No. 1 to prepare a 100 mg/kg solution, and soak the base 3 cm of the cuttings in the solution for 0.5 to 1 hour. Or soak them in a 50 mg/kg naphthalene acetic acid solution for 12 hours, take them out and leave them for a moment before planting. The rooting rate can reach more than 95%.
4. Cutting method
The plant spacing for cuttings is 8 cm to 10 cm, and the row spacing is 15 to 20 cm. First use a wooden stick to make slanted holes of appropriate depth, then insert the lower 2/3 of the cuttings obliquely into the soil, just enough to expose the upper axillary buds and leaves, then press the surrounding soil slightly firm, and finally water thoroughly with a 500 mg/kg carbendazim solution, which serves to fix the roots and disinfect the soil.
5. Management after cutting
1. Shading and watering. At 0.3 m and 1.7 m above the bed surface, build one shade shed each, both covered with bamboo blinds or shade nets with 30% light transmittance. Keep the temperature inside the shed at 24°C to 28°C and the relative humidity above 85%. On sunny days, spray water 2 to 3 times a day. The soil moisture content should be 90% in the early stage and 70% to 80% in the middle and late stages. Cover the high shade shed in the morning and uncover it at night. Generally, callus tissue forms 10 days after cutting, and roots and survival are achieved in about 20 days.
2. Fertilization and spraying. After the cuttings grow 2 to 3 leaves, apply 10% clear liquid manure, 2 to 3 times a month. During the seedling stage, it is best to spray 1 to 2 times a month with a 1000-fold dilution of 50% carbendazim wettable powder, or spray 0.5% Bordeaux mixture, to prevent red leaf spot and damping-off. The main pests during the seedling stage are aphids, leaf rollers, and leaf-eating insects, which can be controlled with pyrethroid and organophosphorus pesticides. When the plant height is above 30 cm, it can be transplanted with soil and planted out from the nursery.