Loquat grafting technology
1. Cultivation of rootstock seedlings
1. Precisely make a seedbed. The nursery site should choose sandy soil that is shady and leeward, has loose soil, is rich in organic matter, has medium fertility, and has good fertilizer and water retention properties. Half a month before sowing (early to mid-May), apply an appropriate amount of decomposed compost, soil fertilizer, pig manure or spread 50 kilograms of compound fertilizer per acre as base fertilizer. Then the soil is plowed, harrowed and leveled to make furrows. Each furrow is 1.2 meters wide and the furrow is 30 centimeters. Where there are underground pests, carbofuran should be used to disinfect the soil before soil preparation to kill underground pests.
2. Sowing. Loquat seeds do not have a dormant period. Before sowing, the loquat cores should be screened to remove small and abnormally developed loquat seeds. Large and plump loquat seeds should be selected, washed and dried before sowing. The sowing period is from late May to early June. There are two methods of sowing: broadcast sowing or drill sowing (drill sowing is generally used). The spacing between drill rows is 20-25 cm, and the spacing between plants is 10-12 cm. Depending on the germination rate of the seeds, 1-3 seeds are sown in each hole. Press lightly when sowing, and press half of the seeds into the soil. Spread a thin layer of fine dust. There is no way to see the seeds. If the seeds are sown too deep, they will be difficult to unearth and may cause mildew; if they are sown too shallow, they will not take root. Immediately after sowing, the seedbed should be watered thoroughly with water, and the soil surface should be thinly covered with moisture-retaining materials such as straw or fresh pigweed to keep the soil surface from compacting and facilitate seedling emergence.
3. Post-broadcast management. Before the seedlings are unearthed, the seedbed should maintain a certain humidity and should not be too dry or too wet. Remove the grass cover after the seedlings emerge. Because loquat seedlings like shade, their leaves are easily burned when exposed to strong sunlight. Therefore, after sowing and before emergence of seedlings, a shade net must be used to set up a shade shed with a height of 50-60 cm. After all the seedlings are gathered, remove weak seedlings, overcrowded seedlings, and diseased seedlings in a timely manner, leaving one strong seedling according to the size of the plant spacing. When the seedlings grow 3-4 true leaves, you can apply dilute human excrement or compound fertilizer every half a month, and remove weeds in time. When the seedling height reaches 20 cm, remove the top 1-2 young leaves to promote thickening of the lower stems, and at the same time, prevent and control diseases and insect pests. Shade nets are removed at the end of August or beginning of September. In the spring of the second year, rootstock seedlings can be grafted when their diameter reaches more than 0.6 cm. Those that cannot be transplanted will be cultivated and managed until grafting in the following year.
2. Grafting of seedlings
1. Selection of scions. The vegetative branches of one-year-old spring shoots or summer shoots with substantial growth and moderate thickness can be selected from local excellent varieties of mature fruit-bearing trees or young fruit-bearing trees as scions, but inner branches or leggy branches cannot be used as scions. After collecting the scions, the leaves should be cut off immediately and wrapped in plastic film to prevent evaporation and water loss from affecting the survival rate. Try to collect and use them as soon as possible. If picking ears from a long distance, remove leaves, moisturize and hide in sand.
2. Grafting time and method. The most suitable time for grafting loquat seedlings is from mid-March to early April when the sap begins to flow. Generally, the cutting method is used. The method is to cut the cultivated rootstock 8-10 cm away from the ground. Choose the straighter side of the scion to make a long shaved surface. First, use a knife to cut a knife at a 45-degree angle on the back, then turn it over and shave a long shaved surface to remove the phloem. , slightly with xylem, shaved surface about 2 cm. The shaved surface is required to be flat, smooth and lint-free. Leave 1-2 buds on each scion and cut them transversely 0.5 cm above the buds. Then select the smooth side of the bark at the cut of the rootstock, first use a knife to cut off a small piece at an angle, and then make a 2 cm long incision downward between the phloem and the xylem, so as to slightly remove part of the xylem. Then insert the long chamfer of the scion into the rootstock incision on the inside of the stock, and align the cambium of the scion and stock. If the rootstock and scion have different thicknesses, they should be inserted side by side to align the cambium on one side. Finally, use plastic film to tie the stock and scion tightly, and then tie and seal the interface between the scion and stock to prevent drying and rainwater infiltration. When bandaging, care should be taken to prevent the aligned cambium from shifting.
3. Management after grafting
1. Remove sprouts. After the grafting is successful, the sprouting tillers on the rootstock should be removed promptly to reduce nutrient consumption and facilitate the growth of the grafted seedlings.
2. Fertilize.
Do not fertilize immediately after grafting. After 40-50 days, when the grafting has basically survived and new shoots have sprouted, apply thin fertilizer frequently once a month, cultivate and weed, manage carefully, and pay attention to drought resistance against high temperatures and droughts in summer.
3. Prevention and control of pests and diseases. For plant diseases and insect pests such as yellow caterpillars and leaf spot, pesticides such as dichlorvos, permethrin, carbendazim, and pyridine can be used for timely and accurate control.
4. Remove the film. In early to mid-September of the year of grafting, the grafting film must be removed in time. If the film is not removed for a long time, it will affect the transportation of nutrients and normal growth.