What is the reason for the low rate of seedless watermelon buds and low seedling rate? Is there any good solution?

[ Agricultural Products Network] What is the reason for the low rate of seedless watermelon buds and low seedling rate? Is there any good solution? Many farmers who grow seedless watermelons often ask such questions. The following is a detailed introduction for you to introduce, for your reference.

1. Reasons for low germination rate and its solutions

1.1 Reasons for low germination rate

There are five main reasons for the low germination rate. First, the embryos are incompletely developed, the embryos are weak, the defective embryos, the folded embryos, and other malformed embryos and no embryos (only the seed coat and the embryo sheath) are more, and the seeds themselves are embryos. Nutrient substances are congenitally deficient, resulting in seed germination weakness; second, the seed coat is thick, the embryo is not easy to absorb water when soaking seeds, the umbilical part is thicker, hindering the seed germination; the third is that the cavity of the seed cavity is large, and the seed embryo is prone to occur due to excessive water in the soaking Water immersion necrosis; Fourth, the temperature conditions are higher, it is not easy to control accurately, the germination is slow when the temperature is low, and the germination is weak; the fifth is improper seed collection time, such as premature harvest, the seeds are not fully mature, and the seed germination rate will be reduced.

1.2 Solution

1 Scientific selection The seeds with sufficient maturity, neat shape and full grain are the prerequisites for obtaining high germination rate, and remove the scorpion seeds and deformed seeds floating on the water surface by scouring before germination. In addition, due to the climate of the seed production, the seeds produced in the northwest region seed production bases such as Xinjiang are often more germinated than the seeds produced in the southern seed production base.

2 Control humidity First, shorten the soaking time. Generally, the seeds should be placed in 55 °C warm water for 20 to 30 minutes, then soaked in cold water for 3 to 4 hours. Second, the environmental humidity of the germination should be controlled. Generally, it is not necessary to spray water or spray water on the seeds, and the humidity of the germination bed or the germination bag should be controlled.

3搓 After the mucus is soaked, the seeds can be washed with lime water before germination, and the sticky substances on the seed coat are removed, because the sticky substances may be harmful to the seed germination.

4 artificial shell breaking artificial shell is a simple and effective way to improve the germination rate of seedless watermelon seeds. The specific method is to bite the teeth or clamp the seed crotch with pliers, grasp the strength, and make the seeds slightly open a gap along the suture. The length of the gap ZUI should not exceed 1/3 of the length of the seed. Note that the force is not too strong to avoid damage to the embryo. According to the results of our comparative test with Black Honey No. 2, except for the shell-breaking measures, all other treatments were consistent, the germination rate of the shell was 91.3%, and the germination rate of the unshelled shell was only 30.6%.

5 high temperature germination adopts high temperature germination and moderate temperature germination method, that is, the germination environment temperature is maintained at 35-36 ° C before the seed germination in the early stage of germination, and after the seed germination, the germination environment temperature is controlled at 32-33 ° C, which can accelerate The seed germination promotes the germination of the buds, reduces the nutrient consumption, increases the germination rate, and makes the germinated buds strong and full.

6 Drug treatment According to our test, soaking seeds with 20~25 mg/L GA3 (gibberellin) solution at 25-28 °C can increase the germination potential. According to the data, the 20 mg/L ABT No. 6 rooting powder solution can increase the germination potential and germination rate.

2. Reasons for low seedling rate and its solutions

2.1 Reasons for low seedling rate

There are four main reasons for the low seedling rate. One is the unearthed shell (commonly known as “with cap”), that is, the seed coat envelops the young shoots, so that the young shoots do not see sunlight and affect the growth of the young shoots; The top of the bud is weak and not easy to emerge; the third is that the seedlings have strict requirements on the seedling conditions. Once they encounter bad weather conditions such as low temperature, they are prone to collapse; the fourth is that the seedlings (before the 2 leaf stage) are weak and slow, and grow slowly.

2.2 Solution

1 Scientific sowing First, the sowing depth should be appropriate, try to make it self-shelling and unearthing, generally the planting depth is 0.6~1.0 cm; the second is that the seed should be laid flat when planting, which is conducive to shelling and unearthing; Suitable, because the top of the young shoots is weak, too thick and not easy to emerge, too thin and not easy to shell, and the young roots are easy to bare, unfavorable growth, ZUI well covered the fine soil 1 cm thick.

2 timely shelling, such as seedlings "with cap" unearthed, should be removed after the seedlings are unearthed, when the seed coat is soft and wet in the morning, carefully remove the "cap" to ensure that the cotyledons are deployed and normal growth in time, pay attention to the "cap" when not hurting Cotyledon.

3 Create suitable conditions to strengthen the temperature and humidity management of seedling bed, create suitable conditions to ensure the healthy growth of seedlings. In early spring, the seedlings can be warmed up and kept warm by a hotbed or a covering, and can be cooled in the summer by covering the shade net and the grasshopper. Before the seedlings are unearthed, control 30 to 32 °C during the day and 18 to 20 °C during the night; before the cotyledons are unearthed until the true leaves are unfolded, control the daytime to 20 to 25 °C, and at night to 16 to 18 °C; after the true leaves are unfolded, control the daytime to 25 to 28 °C. 17 to 19 ° C at night.

Adjust the humidity of the seedbed and properly ventilate. The nutrient soil or seedbed soil is poured through the bottom water one day before sowing. Generally, no water is sprayed before emergence. After emergence, the water is sprayed according to the humidity of the seedbed and the growth of the seedlings. The cotyledons should be ventilated after being unearthed. The ventilation time is short and long, and the ventilation is small. And big.