Tomato grafting technology

There are many ways to graft tomatoes, so tomato grafting still requires certain skills. Here is a detailed introduction:

1. Variety selection is mainly the choice of rootstock

Generally, wild bred tomato varieties with high resistance to root-knot nematode disease and bacterial wilt are selected. At present, tomato grafting in China is still in the experimental stage. There is no rootstock that can completely resist all subspecies of bacterial wilt. Usually, it is only highly resistant to a few subspecies. Therefore, it is necessary to clarify the physiological subspecies of tomato bacterial wilt in the planting area, and then select the corresponding rootstock. The general method is to purchase multiple rootstocks from different regions for experimental cultivation to determine. Conventional varieties can be used for scion.

2. Cleft grafting method with suitable sowing period for rootstock and scion

Generally, the rootstock should be sown 7-10 days in advance, and the rootstock should be transplanted into the nutrient cup when it has one leaf and one heart. When the rootstock grows to 8 to 10 cm in height and the stem is 0.5 to 0.8 cm thick, it can be grafted. Cut the rootstock stem horizontally with a blade, remove the upper part, split it from the middle of the stem, and cut 1 to 1.5 cm longitudinally toward the opening. Then pull up the scion seedling, keep the upper 2 to 3 true leaves, cut off the lower part with a blade, and cut the upper cut into a wedge shape. The size of the wedge should be equivalent to the incision of the rootstock. Then insert the scion into the rootstock, align it and fix it with a clamp. If conditions permit, the scion can be the axillary bud of the tomato mother plant, which can not only save seed costs, but also improve the grafting survival rate and bring the fruit to market earlier.

3. Grafted seedling management should be timely after grafting

Water the seedbed fully and cover it with a small arch shed. Do not let in air for 6-7 days and keep the air humidity above 95%. The temperature should be 20-26℃ during the day and 16-20℃ at night. Prevent the temperature from being too high or too low. When the temperature is too high and the sun is strong, cover it with a sunshade net. In low temperature periods, use artificial heating wires to supplement the temperature to prevent the plants from being frozen.

After grafting, the plant should be completely shaded for 4-5 days, and then the exposure time should be gradually increased every day. As the wound gradually heals, remove the shade net and uncover the plastic film on both sides for ventilation. The ventilation should be small at first and gradually increased. During the ventilation period, the air humidity in the shed should be maintained at a high level, and the ground should be watered frequently. After the plant fully survives, normal management should be resumed. After the plant survives, remove the lateral buds that sprout from the rootstock in time, and remove the clips after the interface is healed and firm.

4. Planting and initial management

Fertilization is very important for greenhouse tomato grafting cultivation. It is required to apply 5000 to 6000 kg of farmyard manure and 40-60 kg of vegetable compound fertilizer per mu. All of them are applied on the ground and turned into the soil to mix evenly. Plant 1800-2000 plants per mu (greenhouse). After the ground temperature is above 15℃, start planting and cover with mulch. Choose sunny weather for planting. First, drill holes and water them, then cover the holes after the transplanting water seeps down. Note that the position of the knife edge should be higher than the surface of the box by a certain distance during grafting to prevent the root of the scion from being contaminated by secondary disease. After planting, pay attention to airtight insulation and no ventilation. The seedlings can be slowed down in one week. The temperature management after slowing down is: 25℃-30℃ in the morning. When it exceeds 35℃, it should be properly ventilated to cool down. In the afternoon, it is 28℃-30℃. When it is below 25℃, the shed should be closed for insulation. Keep it above 20℃ during the day and 10℃-15℃ at night.