With the arrival of March, citrus shoots begin to come to life, marking a rather complex task for growers – to promote healthy spring shoots and to ensure that the flowers are strong. Both are indispensable. If the management of citrus shoot growth is not in place, it may lead to uneven growth of spring shoots and difficulty in maintaining strong flowers, which will bring great problems in the later fruit preservation process. However, the difficulty of management also lies in the variability of the weather in the spring. This year's weather is forecast to go through three phases: sunny (spring shoots germination), rainy (spring shoots growing and whitening), and cool (spring shoots growing and flowering).
First of all, in terms of promoting flowering and strengthening flowers, for trees with moderate or weak strength, you can choose to apply products containing humic acid and seaweed extracts when budding, and supplement trace elements such as boron, zinc, calcium, copper, etc. as appropriate. Foliar sprays of biostimulants, such as amino acids, may be considered to improve flower quality. At the same time, it is necessary to prevent the possible inverted spring cold. A wave of cooling is expected in early March, accompanied by rainfall, which can lead to uneven bud differentiation and the appearance of misshapen flowers. Therefore, it is very important to improve the stress resistance of citrus and ensure the normal differentiation of flower buds. For trees that have not been picked or whose autumn shoots are not full, flowering is even more important. Phosphorus, potassium and boron, such as potassium dihydrogen phosphate and highly concentrated liquid boron in dry leaves, should be appropriately supplemented during the budding period to regulate the tree potential and stimulate flowering.
Secondly, it is also crucial to adjust the tree potential. The balance of vegetative growth and reproductive growth of trees needs to be coordinated. For trees with fewer flower buds but more shoots, potassium dihydrogen phosphate can be supplemented, and some spring shoots can be thinned to ensure that the flower buds receive sufficient nutrient supply. Circumcision may be considered if necessary. In the case of more flowers but weak trees, pruning the upper part of the tree can balance the tree's momentum, and at the same time strengthen the nutrient supply, actively protect the flowers and fruits, and reduce the pressure on the summer shoots. When it comes to fertilization, make sure to use germinating fertilizer. The germination fertilizer of citrus is mainly based on fast-acting fertilizer and compound fertilizer, which is sprinkled before light rain, drenched during drought, and fertilized quickly after heavy rain. It is recommended to use balanced fertilizer or apply it with instant chelate fertilizer or irrigate the roots with water.
Finally, pest control is also crucial. During the spring shoot period, the pests that need to be controlled include flower bud maggots, thrips and aphids. Flower bud maggots and thrips mainly damage flower buds. The control of flower bud maggot is more complicated, the adult overwinters in the soil, and when the citrus begins to germinate, it lays eggs in the flower bud and hatches into maggots, harming the flower organs. Therefore, the focus of the control of bud maggots is to seal off the adult worms and prevent them from coming out. If the adult worms have appeared, they need to be treated immediately, otherwise they will lay eggs in the flower buds, which greatly reduces the control effect. Thrips are a frequent pest of citrus, which can be harmful from the bud stage to the fruiting stage, eating the buds and young fruits, causing the citrus to grow up and have a flower skin, affecting the quality of the fruit. Aphids mainly eat the young parts of leaves, resulting in leaf deformity and stunted development, affecting the growth of new shoots. For these three insect pests, 26% acetamiprid 750 times + 5% avermectin 1500 times can be used for control.
During the spring shoot period, the diseases that need to be focused on include anthracnose, scab and gray mold. These diseases are fungal diseases, which can be prevented and controlled by using 4000~5000 times of 75% oxime tebuconazole, and it is also necessary to reasonably manage fertilization and water, and be alert to adverse weather conditions such as excessive rainfall and cold spring. We recommend the use of amino acid foliar fertilizer and pesticide compound use while controlling pests and diseases, which can not only control diseases but also improve the stress resistance of fruit trees, so as to cope with the double blow of pests and diseases and bad weather.