The quality of cucumber seedlings can be said to directly affect the yield and quality of cucumbers in the later period. Most of the cucumber seedlings currently on the market are grafted with pumpkin seedlings as rootstocks and cucumber seedlings as scions. Today, I will introduce to you a new grafting method, cucumber double root cutting grafting technology. Compared with the commonly used grafting technology now, the biggest difference of cucumber double-root grafting technology is that during grafting, the roots of the rootstock and scion seedlings are cut off at the same time, so that the rootstock can produce more lateral roots. Using cucumber double-root grafting Cucumber seedlings cultivated through technology not only grow well and have high yields, but are also more resistant to aging and disease.
1. Preparation before grafting
When cultivating seedlings with double root cutting grafting technology, most of them are in autumn, winter and spring. Grafting seedlings need a suitable site, and you can choose to insulate them. It should be carried out in a multi-span greenhouse or solar greenhouse with good light transmission, and the necessary heating and insulation facilities should be equipped.
1. Healing room
Cucumber seedlings that have just been grafted have high environmental requirements. It is best to equip a qualified nursery with a healing room. The healing room must have facilities such as moisturizing photos, sunshade nets, and fans.
2. Prepare the substrate and plug trays
The use of double root cutting grafting technology to raise seedlings requires a loose substrate and good air permeability. Before sowing, the substrate and plug trays need to be disinfected and the substrate must be sufficient. moist. In actual production, large-scale intensive seedling factories can produce and mix seedling substrates by themselves.
3. Select rootstock and scion varieties
Selecting appropriate rootstock and scion varieties is also critical. It is suitable to choose rootstocks that have strong affinity with cucumbers, good root regeneration, and good disease resistance, such as white-seeded pumpkins. The scion should be adapted to local conditions and time, and the main local varieties should be selected according to the needs of farmers and market demand.
4. Seed treatment
Before sowing, soak the seeds in warm soup. The water temperature is between 50 and 55°C. Slowly pour the seeds into the pot and stir while pouring. The ratio of water is 1:5 and lasts for 15 to 20 minutes to allow the seeds to heat evenly. In order to reduce the occurrence of root diseases during the seedling cultivation period, some microbial agents need to be added. It is recommended to use Trichoderma harzianum T-22 spore wettable powder with 600 million spores per gram, which can prevent pythium, damping off, and cucumber sickle. Bacterial wilt, etc., and can also increase the seed emergence rate.
The ratio of this agent to water is generally 1:2000. Pumpkin seeds need to be soaked in a uniformly mixed solution for 8 to 12 hours. Cucumber seeds need to be soaked for a shorter time, about 4 to 5 hours, until the seeds absorb water. After swelling, remove the seeds, clean them, wrap them in wet cloth, and put them into a germination machine. The temperature of the germination machine is set between 28 and 30°C. Generally speaking, the germination time of pumpkin seeds is 36 hours, and the germination time of cucumber seeds is between 18 and 24 hours. When the seeds have turned white, they can be sown.
5. Sowing of rootstocks and scions
Sow pumpkin seeds one in each hole. The sowing depth should be controlled at about 1 to 1.5 centimeters. When sowing, the seeds should be laid flat so that the seeds The radicles can be dug downward to reduce the appearance of "hatted seedlings"; cucumber seeds are also sown one hole at a time, and the sowing depth is controlled at about 1 cm. After sowing is completed, the plug tray must be watered thoroughly. When sowing, the rootstock is generally sown first, and then the scion. The interval is related to the local climate and other factors. In principle, it is appropriate to achieve simultaneous grafting standards.
6. Management after sowing
From sowing to before emergence of rootstocks and scions, the greenhouse temperature should be appropriately high. Generally, the temperature in the greenhouse is controlled at 28°C during the day and around 25°C at night. ; Moisture management at this time is relatively simple, as long as the lower half of the hole is always moist, and the upper half of the matrix alternates between dry and wet.
After the seeds emerge, they need to be observed in time. If "hatted seedlings" are found, the seed coats should be removed in time. After emergence, the temperature can be appropriately lowered. Generally, the daytime temperature can be maintained at 20~25℃, and the night temperature can be maintained at around 15~20℃.
2. Double root cutting grafting operation
The rootstock has grown to have one leaf and one heart, and the first true leaf is about 1 cm long. Grafting is carried out when the scion cotyledons are flat. 1~ before grafting For 2 days, the rootstock should be cooled down. The daytime temperature should be controlled at 18~23℃, and the nighttime temperature should be controlled at 13~18℃. Stop watering the day before grafting. Through cooling and water control management, the lower part of the hypocotyl of the rootstock can be hardened, which is conducive to rapid rooting after grafting of the rootstock.
During grafting, the ambient temperature should be controlled at around 20~25℃. The first step of double-root grafting is to cut off the root of the rootstock. At the upper part of the pumpkin seedling, about 4 to 5 cm away from the cotyledons, use a blade to cut off the hypocotyl of the rootstock in the horizontal direction, remove the growth point at the top of the rootstock, and then graft Tilt the knife to 45°, close to the surface of the cotyledon's petiole, and insert it obliquely toward the base of the other cotyledon's petiole. The diameter of the oblique insertion is 0.8~1 cm. The grafting knife should penetrate about 0.2 cm of the rootstock epidermis, with the tip of the grafting knife just exposed as the should.
After the rootstock is threaded, the next step is to cut the scion. Tilt the blade about 30°, and make a bevel cut about 2 cm below the base of the scion. The bevel should be smooth and the length should be about 0.8 cm. Remove the grafting knife, insert the scion into the rootstock socket quickly and accurately with the bevel facing downwards, and at the same time, make the cotyledons of the rootstock and scion cross in a cross shape. The insertion depth of the scion should be such that the front end is cut off to expose the grafting hole, and the rear end is cut to be flush with the rootstock socket.
In order to promote rapid rooting, the grafted cucumber seedlings should be dipped in a certain concentration of rooting agent. It is recommended to consult local technical personnel for the specific type and concentration. After grafting, it should be inserted into the plug matrix in time. It is best to control the insertion depth of the hypocotyl to about 1 cm. If the hypocotyl is inserted too deep or too shallow, it is not conducive to hair roots. It is best to leave 3 to 4 cm in the upper part. Leave too much. Whether it is too long or too short will affect the survival rate to a certain extent. If the cotyledons of decisive rootstocks are left behind, they will easily grow into the substrate, leading to rot; if they are left too long, the seedlings will be prone to lodging during their growth, and there will be more contact between the seedlings, which will also lead to leaf rot.
At the same time, all tools should be disinfected during the grafting process. During the operation, it is forbidden to touch the grafting wound directly with your hands.
3. Post-grafting management
The grafted cucumber seedlings must first be healed in the healing room. 1 to 3 days after grafting, the daytime temperature of the callus room should be controlled at 28 to 30°C, and the nighttime temperature should be controlled at about 18 to 20°C. Once the temperature and humidity are too low, it will often affect the healing of the scion and rootstock wounds and cause the rootstock to take root slowly. During this period, a sunshade net should be covered to reduce sunlight.
4 to 5 days after grafting, the relative humidity of the air in the callus room is controlled at 70% to 80%, the daytime temperature is controlled at 25~28℃, and the nighttime temperature is controlled at around 16~18℃. During this period , you can open the moisturizing cover for half an hour to 1 hour around 10 am or 4 pm to provide moderate light and ventilation. In addition, water should be sprayed once a day to prevent the scion from losing water and wilting.
1. Seedling management
6 to 7 days after grafting, the moisturizing cover can be removed, and the grafted seedlings can be moved out of the callus room and transferred to the seedling workshop. Scientific ventilation should be carried out in the seedling workshop, and the air humidity in the seedling workshop should be controlled between 60% and 85%. The daytime temperature should be controlled at 22~28℃, and the night temperature should be controlled at around 15~18℃.
2. Low-temperature seedling hardening
The grafted seedlings need to be hardened at low temperature one week before planting. During the seedling hardening period, the greenhouse temperature is generally controlled at 18~20℃ during the day and 10~ Between 12℃, it can drop to 8~10℃ in a short time. During the seedling raising period, when the surface of the substrate has become dry, you can use spraying to water. Combined with watering, spray 0.1% potassium dihydrogen phosphate and urea mixed aqueous solution 1 to 2 times, which can promote root development and growth.
3. Planting of grafted seedlings
Observe the grafted seedlings when the grafting interface heals well, the cotyledons of the grafted seedlings are intact, reaching two leaves in one center, or the scion true leaves reach 2 to 3, and the leaf color If it is dark green, the stems are thick, and the root system is intact, the seedlings are ready for planting.
For cucumber seedlings treated with cucumber double root cutting grafting technology, the rootstock will grow multiple lateral roots again. Such grafted seedlings will have more root systems and stronger vitality. After transplanting, the seedlings will have a short recovery time. . During the seedling cultivation process, the cucumber seedlings cultivated by double root cutting grafting have better root system water and fertilizer capabilities and resistance to soil-borne diseases than ordinary grafting methods. The plants grow stronger and more prosperous. In the middle and late stages of plant growth, the root system senescence is relatively high. slow.