Urea is a commonly used available nitrogen fertilizer and has many other uses in addition to top dressing.
First, to adjust the amount of flowers In order to overcome the size of Apple, in the case of young years, 5-6 weeks after flowering (the critical period of apple flower bud differentiation, new shoots grow slowly or stop, the leaf nitrogen content showed a downward trend) leaf spray Application of 0.5% urea aqueous solution, even spraying 2 times, can increase the leaf nitrogen content, accelerate the growth of shoots to inhibit flower bud differentiation, so that the amount of flowers in the year is appropriate.
Second, the thinning and fruiting fruit trees are more sensitive to urea, but the surface reaction is less blunt. Therefore, foreign countries used urea on peaches and nectarines for fruit thinning and fruit thinning tests. The results showed that peach and nectarine sparsely As a result, a large concentration (7.4%) is required to show good results. The most suitable concentration is 8% to 12%. Within 1-2 weeks after spraying, the purpose of thinning and fruit thinning can be achieved. However, under different land conditions, the reaction of different periods and different species still needs further tests.
III. Seed Production in Hybrid Rice In order to increase the outcrossing rate of parents in order to increase the seed production of hybrid rice or the breeding amount of sterile lines, the use of maternal parent spray to reduce the female parent The degree of wrapping the neck can be fully extracted; or spraying the parent's book, adjusting the growth of both to synchronize the flowering period. As gibberellin is more expensive, its seed production costs are high. People experimented with urea instead of gibberellin, and used 1.5%-2% urea in the prophase of panicle and heading stage (20% heading). The effect of the multiplication was similar to that of gibberellin, and it did not increase plant height.
Fourth, control pests use urea, detergent, water 4:1:400, stir and stir to prevent fruit trees, vegetables, cotton aphids, red spider, cabbage caterpillar and other pests, insecticidal effect of 90% or more.
Five, urea iron fertilizer urea in the form of complexes, with iron chelate chelation. This organic iron fertilizer has a low cost, and it has a good effect in preventing iron deficiency and chlorosis. In addition, when 0.3% urea was added when 0.3% ferrous sulfate was sprayed on the leaves, the effect of preventing and controlling chlorosis was better than that of single-spraying 0.3% ferrous sulfate.
First, to adjust the amount of flowers In order to overcome the size of Apple, in the case of young years, 5-6 weeks after flowering (the critical period of apple flower bud differentiation, new shoots grow slowly or stop, the leaf nitrogen content showed a downward trend) leaf spray Application of 0.5% urea aqueous solution, even spraying 2 times, can increase the leaf nitrogen content, accelerate the growth of shoots to inhibit flower bud differentiation, so that the amount of flowers in the year is appropriate.
Second, the thinning and fruiting fruit trees are more sensitive to urea, but the surface reaction is less blunt. Therefore, foreign countries used urea on peaches and nectarines for fruit thinning and fruit thinning tests. The results showed that peach and nectarine sparsely As a result, a large concentration (7.4%) is required to show good results. The most suitable concentration is 8% to 12%. Within 1-2 weeks after spraying, the purpose of thinning and fruit thinning can be achieved. However, under different land conditions, the reaction of different periods and different species still needs further tests.
III. Seed Production in Hybrid Rice In order to increase the outcrossing rate of parents in order to increase the seed production of hybrid rice or the breeding amount of sterile lines, the use of maternal parent spray to reduce the female parent The degree of wrapping the neck can be fully extracted; or spraying the parent's book, adjusting the growth of both to synchronize the flowering period. As gibberellin is more expensive, its seed production costs are high. People experimented with urea instead of gibberellin, and used 1.5%-2% urea in the prophase of panicle and heading stage (20% heading). The effect of the multiplication was similar to that of gibberellin, and it did not increase plant height.
Fourth, control pests use urea, detergent, water 4:1:400, stir and stir to prevent fruit trees, vegetables, cotton aphids, red spider, cabbage caterpillar and other pests, insecticidal effect of 90% or more.
Five, urea iron fertilizer urea in the form of complexes, with iron chelate chelation. This organic iron fertilizer has a low cost, and it has a good effect in preventing iron deficiency and chlorosis. In addition, when 0.3% urea was added when 0.3% ferrous sulfate was sprayed on the leaves, the effect of preventing and controlling chlorosis was better than that of single-spraying 0.3% ferrous sulfate.