Grafting Seedling technique of Cucumber in greenhouse

???? 1. Preparation before grafting

1.1 Selection of cucumber rootstock

There are many rootstocks suitable for grafting cucumber, such as Chinese pumpkin, loofah, gourd, etc., but most of them have great influence on cucumber quality, and their compatibility is poor, and the grafted cucumber tastes bad. According to the experience in recent years, black-seeded pumpkin is the best rootstock for cucumber grafting because of its low temperature tolerance and good compatibility with cucumber.

1.2 seed selection

Black seed pumpkin seeds must choose darker mature full seeds. Because cucumber grafting is mainly based on the resistance of rootstock to soil-borne diseases, and other diseases still depend on the resistance of cucumber varieties themselves, and the characteristics of grafted cucumber are also owned by cucumber itself, therefore, cucumber seeds must be selected with better compatibility.

1.3 seed treatment

Sunning seeds 2- 3 days before sowing can eliminate bacteria and make buds neat. Seed disinfection: ① high temperature disinfection. Seeds can be killed or inactivated by putting them into water at 90--95 ℃ for 5--7 s.② Warm soup disinfection. The seeds are placed into 50--55 ℃ salt water and stirred continuously, blanched for 15 min, and then placed into 25--50 ℃ warm water for 4--6 h.③ Potassium permanganate disinfection. Soak seeds with 0.1%--0.5% potassium permanganate solution for 3 hours and then wash with clean water.④ Sodium phosphate disinfection. The mosaic virus on the surface of seeds can be killed by throwing seeds into 0.1%--0.5% sodium phosphate solution.

1.4 Preparation of grafting tools

1 Bamboo salt. Prepare a bamboo stick 5- 6 cm long. Select the harder bamboo green part, cut it into wedge shape at the tip of bamboo stick 0.5 cm, the top is even, the width is about 3 mm, which is equivalent to the stem thickness of cucumber. The tip of the stick must be smooth and smooth to facilitate grafting survival. 2 blade. The razor blade can be divided into two parts, half of which should be sharp; plastic cloth, cotton thread or adhesive tape can be used for grafting special clips.

???? 2. grafting methods

2.1 plug method

When selecting the grafting method, black seed pumpkin should be sown first, then cucumber, the difference between the two is about 5 days, and the black seed pumpkin can be grafted when it grows to 2 leaves and 1 heart, and cucumber can grow to 2 leaves and 1 heart. The specific operation is as follows: 1 day before grafting, the nutrient bowl of black-seed pumpkin is watered thoroughly to improve the grafting survival rate. First remove the top bud of black-seeded pumpkin, that is, the growth point, hold the bamboo stick with your right hand, hold the hypocotyl of black-seeded pumpkin with your left thumb and forefinger, and insert the top of the bamboo stick close to the inner side of the base of the cotyledon of the rootstock obliquely below the other cotyledon. The depth of insertion is generally about 0.5 cm. Do not penetrate the surface to prevent the scion from producing adventitious roots; Do not penetrate the hollow part of the rootstock stem without reaching the inner side of the stem wall on the other side of the stem, so as not to form small old seedlings. Then cut the scion of cucumber, select healthy cucumber seedling, pinch 2 cotyledons of cucumber with left thumb and ring finger, clamp the root part of cucumber with index finger and middle finger, straighten hypocotyl of cucumber, pinch blade with right thumb and index finger, cut from 0.4--0.5 cm below cucumber cotyledons, and cut 1 knife on opposite sides. The cut scion, the length of its knife edge, scion thickness and rootstock incision should be consistent, the knife edge should be smooth. The first knife can be cut longer, the second knife is generally controlled at about 0.5 cm, the knife edge is cut into wedge shape, after the scion is cut, the bamboo stick is pulled out from the rootstock, and the scion is inserted and gently pressed to fully match the scion with the rootstock, leaving no gap. The scion cotyledons and rootstock cotyledons form a "cross", and the scion insertion depth is to cut the scion mouth flush with the rootstock. The whole process from cutting to scion insertion should be stable, accurate and fast. The grafted cucumber seedlings are immediately placed in the arched shed in advance, and the ground in the shed should be watered first to increase the humidity of the ground to facilitate survival. Spray some water with a sprayer every few rows. The droplets should not be too large and should not be sprayed at the interface. After arranging, cover tightly with plastic cloth, and carry out moisture retention, heat preservation and shading treatment.

2.2 abutment

Cucumber should be sown 5 days in advance by grafting. Cucumber and pumpkin are sown in seedling tray evenly. When the stem height of both is about 7 cm, the grafting is best. The concrete method is as follows: firstly, the rootstock seedling and scion seedling are taken out from the seedbed, the growth point of pumpkin seedling is cut off with sterilized blade or bamboo stick, and the side parallel to the cotyledon direction is cut downward at 45° with blade at the position of 0.5--1.0 cm below the cotyledon, and the depth reaches 2/5--1/2 of the cotyledon, and the length is about 1 cm. then scion is taken, the position 1.5 cm below the cotyledon is obliquely cut upwards by 30 degrees in the direction perpendicular to the cotyledon, the depth reaches 1/2--2/3, the length is equal to that of the rootstock, the rootstock is embedded with the cut of the scion, the joint is gently pinched by hands, the joint is not loosened, the joint is prevented from being misplaced, and then the joint is fixed by a grafting clamp, so that the cucumber cotyledon is higher than the pumpkin seed leaf to form a cross shape. Close to the good, immediately plant seedlings into the nutrition bowl, and into the arch prepared in advance, pay attention to planting gently grasp the grafting joint site. In order to avoid scion contact with soil to produce adventitious roots, the distance between stem and root should be about 1 cm, and the interface should be 3--4 cm away from nutrient soil. Before successful contact, rootstock and scion should have roots respectively. After grafting for 10- 15 days, the bandage should be removed in time, and the scion root system should be cut off with a blade. After cutting off the root, the seedlings should be cooled and cultivated.

???? 3. Grafted seedling management

3.1 temperature

Generally, within 3--5 days after grafting, keep 24--26 ℃ during the day, not exceeding 27 ℃; 18--20 ℃ at night, not lower than 15 ℃. 3--5 After d, start ventilation and gradually reduce the temperature. During the day, it can drop to 22--24 ℃. 12--15 ℃ at night.

3.2 moisturizing

The relative humidity of arch shed should be kept between 85% and 90% within 3- 5 days after grafting, but the soil humidity of nutrient pot should not be too high to avoid rotting seedlings.

3.3 light shielding

Cover small arched shed with thin straw cover or sunshade net, adjust temperature and humidity appropriately according to weather conditions, when temperature is low, open straw cover to accept weak light scattering. Shading around noon, gradually increasing the time of light, no longer shading after 1 week.

3.4 ventilation

After 3--5 days of grafting, when the grafted seedlings begin to grow, ventilation can be started, the ventilation should be small at the beginning, gradually increased and gradually extended, generally 9--10 days for large ventilation. After ventilation, pay attention to observe the seedling situation. When wilting is found, replenish water and shade in time.

3.5 Cut the hypocotyl of the scion

The hypocotyls of cucumber were cut off from the grafted seedlings at 10- 12 d. The method is to cut 1 cut at 1 cm below the interface, and then cut 1 cut near the ground. The purpose of cutting 2 cuts is to prevent hypocotyl from re-healing.