Detailed Explanation of the Latest Grafting Technique Essentials for Greenhouse Melons
I. Grafting Method
Sow melon seeds in the seedling bed at a spacing of 10 cm×10 cm. Use white-seed pumpkin as the rootstock, and sow the pumpkin seeds in nutrient pots 20-30 days later than the melon seeds, or sow the pumpkin seedlings after the first true leaf of the melon seedlings grows to the size of a five-fen coin, so that the stem diameters of the two are close to each other at the time of grafting. After the two cotyledons of the pumpkin seedlings have fully unfolded, generally after 8-10 days, make a downward diagonal cut at a 40° angle below the growing point of the pumpkin seedling, and remove the growing point of the pumpkin seedling and one of its cotyledons. For the scion (melon seedling), make an upward diagonal cut at a 30° angle 1-1.2 cm below the true leaf, cut off the tender tip of the melon, so that the length of the scion cut is equivalent to the length of the rootstock cut. Fit the cuts of the rootstock and scion closely together, then secure the joint with a grafting clip.
II. Post-Grafting Management
Immediately after grafting, pour a small amount of water into the nutrient pot to ensure water supply. Cover the grafted seedlings with a low tunnel and seal it tightly. After grafting, uncover and cover the greenhouse straw mats as usual to maintain the indoor temperature. At noon when the sunlight is strong, shade the low tunnel with newspaper, kraft paper, etc. to prevent sunburn. Within 3 days after grafting, control the daytime temperature at 28°C-32°C and the nighttime temperature at 20°C-22°C. Within 2-3 days after grafting, the low tunnel in the greenhouse must be kept sealed so that the air humidity inside the tunnel is maintained at 90%-100%. After 3 days, the daytime temperature can be lowered to 26°C-28°C and the nighttime temperature to 18°C-20°C, and the ventilation opening at the top of the low tunnel can be opened during the day for ventilation. The ventilation opening should be enlarged gradually from small to large, and after 7 days the low tunnel can be removed. About 7 days after grafting, the wound has basically healed; at this time, cut off the root of the scion so that the scion and rootstock form a whole. After the graft has survived, promptly remove the newly growing side buds on the rootstock to save nutrients and benefit the growth of the grafted seedlings.
III. Operating Tips
1. When using this method for grafting, the melon seedlings can be sown appropriately earlier; it is better to let the melon seedlings wait for the pumpkin seedlings than to let the pumpkin seedlings wait for the melon seedlings. This is because after the pumpkin seedlings grow larger, their stems will become hollow, and if the stems of the pumpkin seedlings become hollow, the survival rate of grafting will be greatly reduced.
2. If the melon seedlings are too large, the stem tip can be cut from the upper part of the melon seedling so that the stem diameters of the melon seedlings and pumpkin seedlings are close to each other; grafting in this way does not affect the grafting effect.
3. When raising pumpkin seedlings, pumpkin seeds can be sown in batches, so that suitable pumpkin seedlings are always available for grafting and to prevent sowing too many at one time, being unable to graft in time, and causing the stems of the pumpkin seedlings to become hollow and affecting survival.