Spraying 500 ~ 1500 mg/L gibberellin solution on completely female cucumber plants can induce some female flowers to become male flowers. This method makes parthenocarpy cucumber self-pollinate, which can avoid artificial emasculation. The progeny obtained are all hybrids of F 1, which can be used to propagate pure female cucumber.
When the first true leaf of all-female cucumber seedlings is fully unfolded, seedlings are treated with 1000 mg/L gibberellin (GA4+7) solution and sprayed three times a week, which can induce the development of male flowers, provide pollen for untreated female plants, and cross parthenocarpy cucumbers. All offspring are hybrids of F 1
Spraying cucumber seedling roots with 15 mg/L 6-BA before sowing and 24 hours after sowing can increase the number of female flowers.
After sowing, sow when the seedlings grow to 3-4 true leaves. After sowing 1 week, the root system of seedlings grows stably. Spraying100-200 mg/L ethephon solution on the whole plant can induce cucumber to produce female flowers at each node, and the results are as follows. Because there are too many female flowers and the assimilates are in short supply, there will be many cucumbers, and some cucumbers must be picked to make the rest grow normally. Cucumber can be eaten after pickling.
Spraying 100 mg/L plasticizer solution on cucumber seedlings at 3-leaf stage can promote the development of female flowers, and spraying plasticizer at flowering stage can induce parthenocarpy.
Spraying 50 ~ 1000 mg/L gibberellin at the second to fourth leaf stage of cucumber can promote the development of male flowers.
When cucumber has 1 ~ 3 true leaves, spraying 10 mg/L NAA solution or 500 mg/L IAA solution can induce cucumber to produce more female flowers.
Seedless fruits of cucumber can be obtained by treating female flowers of cucumber with 1%, 2.5% and 5% wool naphthalene acetate at flowering stage.
Spraying 200 ~ 300 mg/L ethephon aqueous solution at the second leaf stage of cucumber and spraying it once every 1 week can effectively improve the seed setting rate and early yield of female flowers.
Spraying 100 ~ 200ml ethephon solution evenly on cucumber seedling leaves (in units of 1 ~ 3 real leaves) and spraying again after the first application of 1 week can greatly increase the number of female flowers.
Spraying 10 ~ 100 mg/L plastic solution on luffa plants can induce the increase of female flowers.
When pumpkin and bamboo shoots are pollinated, NAA solution of 100 ~ 200mg/L is coated on pistil stigma or receptacle with a brush to prevent young pumpkin from falling off and bearing seedless pumpkin. The effect of coating the pistils of bamboo shoots and melons with 50 mg/L NAA solution is the same.
Treating melon, zucchini, pumpkin and watermelon with 100 ~ 200mg/L ethephon solution can inhibit the formation of male flowers and improve the female flower rate. Because of the increase of fruits, the supply of assimilates is relatively insufficient, which will affect the weight of single fruit, so it is necessary to increase watering and fertilization appropriately.
Treating watermelon flower buds with 100 mg/L indoleacetic acid solution once every other day can induce female flower formation.
Male flowers of dioecious gourds often appear earlier than female flowers, so they bear fruit later. Spraying 5 ~ 6 leaves of gourd seedlings with 100 ~ 200mg/L ethephon solution can inhibit the formation of male flowers, promote the development of female flowers and set fruit early. The concentration of ethephon should be different for different varieties. 100 mg/L is suitable for early-maturing varieties, and the concentration of late-maturing varieties should be appropriately increased to 200 ~ 300 mg/l.