What foliar fertilizer to apply to citrus latest, and precautions for spraying fertilizer
Citrus has a long growing period, and during cultivation and management, nutrient deficiency symptoms often easily occur. Direct fertilization takes effect very slowly, while foliar spraying of fertilizer can often quickly improve the yellowing of leaves caused by nutrient deficiency. Therefore, foliar spraying of fertilizer is very common. So what is generally sprayed in foliar fertilizer spraying, and what should be noted during the entire spraying process? This is what we are going to introduce now.
1. Suitable fertilizers
Citrus is prone to calcium deficiency and boron deficiency. When these two elements are lacking, the pectin calcium produced in the fruit is insufficient, which may cause fruit cracking and affect fruit quality. Therefore, 0.1% borax and 1% superphosphate can be sprayed. Before flowering, in order to increase the flowering rate, a mixed solution of 0.5% urea, 2% superphosphate, and 2% potassium sulfate needs to be sprayed. Spraying 0.4% urea and 0.2% monopotassium phosphate can reduce fruit drop. Spraying 0.3% urea, 3% superphosphate, and 0.5%-1% potassium sulfate is mainly for fruit enlargement.
2. Fertilizer concentration
When using foliar fertilizer, be sure to use the appropriate concentration. Do not use too high a concentration, as high concentration will damage the leaves and cause yellow leaves, and then the fertilizer also cannot be absorbed. If the concentration is too low, the plant's absorption effect will not be good, so the appropriate concentration for spraying fertilizer should be adjusted according to the fertilizer.
3. Spraying time
Generally, in different growth cycles, the fertilizer requirements are different. During the fruit growth period, calcium and boron need to be supplemented, while in other periods, other fertilizers are needed for other purposes. Generally, the specific time for spraying fertilizer is on cloudy days or in the relatively humid morning. Or in the evening. Spraying fertilizer when humidity is high, there is no direct sunlight, and the temperature is cool makes it easy to absorb and does not damage the leaves.
4. Spraying site
Foliar fertilizer spraying is generally done on the back of the leaves, because the back of the leaves has no cuticle and is easy to absorb. The front of the leaves has a cuticle, so absorption is relatively less effective. Also, the stomata are on the back of the leaves, making absorption very easy, and the stems can also be sprayed. It can also be combined with root fertilization, and the effect is relatively good.
What citrus foliar fertilizer spraying mainly uses is various chemical fertilizers, such as urea and monopotassium phosphate. Attention should be paid to the spraying concentration, spray on the appropriate site, and choose the appropriate time for spraying.