1 Vigorously promote healthy cultivation technology
Under natural conditions, the navel orange red spider has many natural predators (such as mites, thrips, grass mites, long-whisker mites, blunt mites and spiders, etc.) in the weeds, due to the food chain between animals and insects, and the bridge between the navel orange tree and the weeds, it is generally difficult to occur in large quantities. However, a large part of the fruit farmers, all year round to clean up the weeds in the orchard, there is no habitat for natural enemies, and even eliminated natural enemies, can only rely entirely on spraying to control, repeated spraying to improve the resistance of red spiders, resulting in red spiders more and more difficult to treat, forming a vicious circle.
Therefore, everyone advocates the cultivation of raw grass in the navel orange garden, so that the navel orange garden retains a certain amount of grass all year round. Raw grass cultivation can use natural grass, but also artificial grass. During the young tree period, you can use the row and the ladder wall to grow grass or plant grass, the tree pocket can go to the grass to keep clean, the adult orchard can grow grass in the whole garden, can improve the ecological environment of the orchard, raw grass can not only protect natural enemies to a certain extent, but also maintain soil moisture, make full use of the natural predators of red spiders to control its harm, and minimize the number of medications. The second is the whole process of drip irrigation to improve the dry humidity of the navel orange garden.
Practice has proved that the drought in the orange garden will aggravate the harm caused by the red spider to the navel orange, so timely irrigation or even dripping during drought can reduce the harm. At the same time, reasonable whole branches pruning, large branches pruning, open the chamber to see the light, to ensure that the spray has no dead angles, all-round prevention of red spiders.
2 Grasp the key prevention and control period and choose green pesticides
The navel-orange-red spider, also known as the orange full-clawed mite, belongs to the leaf mite family. Red spiders occur in 15 to 17 generations a year, overlapping generations, and overwintering with eggs and adult mites on the back of the dead leaves, curly leaves and cracks in branches, which is difficult to control and control. In the Gannan region, if it is a warm winter, the red spider has no obvious overwintering stage, and the number of red spiders will increase rapidly. If it is a cold winter, it has a certain inhibitory effect on red spiders, but it cannot be taken lightly, and the insect population base must be lowered from the end of February to the beginning of March to avoid the peak of the occurrence of red spiders in April and June due to the large insect population base. It is crucial to grasp the prevention and control indicators and select the types of agents in each period.
Generally, the spring control index is three or four heads per leaf (with a mite leaf rate of 65%), and in summer and autumn, it can be increased to 5 to 7 heads/leaf (with mite leaf rate of 85%). Focus on the general treatment or pick-up treatment in the peak period of April-May and September-October, and cross-medication to prevent drug resistance. Before the germination of navel oranges in spring, spray with 95% motor oil emulsion 200 times liquid + 5% nissolan emulsion 1000 times liquid at a temperature of 20C or above. Autumn from September to October, is another blooming period for red spiders, this period can be used to spray red spiders with 200 times the liquid on sunny days, the effect is ideal, but we must pay attention to prevent the drug damage of washing powder to young leaves.
In the winter Qingyuan, after the navel orange fruit is picked from the tree, according to the degree of occurrence of red spiders in the orchard, the whole garden is carefully sprayed with the imported oil emulsion of South Korea, and the prevention effect is longer and the effect is more ideal.
Red spiders are highly resistant, and the medication must be rotated, and the number of uses of the same agent in a year is best not to exceed 2 times. Such as Nisoran, crete, etc., it is best to use it only once a year, the effect is better. Second, the vast majority of anti-red spider drugs are touch-killing, and must be very careful and thorough when spraying. Third, some agents will cause medicinal harm to navel orange fruits, and should pay attention to medication during the fruit tree hanging fruit, such as mite, oil emulsion, etc.
In the production process of navel orange, because the copper preparation has a certain prevention and control effect on the navel orange ulcer disease, but the use of copper preparation will promote the occurrence of red spiders, so the prevention and treatment of navel orange ulcer disease should be used as little as possible or without copper preparations, according to the insect situation forecast, when the control indicators are reached, the use of natural enemies is relatively safe, and there is no harm to the navel orange fruit to control the red spider to avoid its harm.
3 Hanging bags prey on mites, and mites are used to control mites
Predatory mites are a kind of citrus red spider, rust ticks and other plant leaf mites as the main food of omnivorous beneficial mites, with predatory mite control citrus red spiders and rust ticks can replace chemical control measures, is one of the important technologies for the production of pollution-free, green citrus.
On the basis of promoting healthy cultivation, before the red spider blooms in spring and autumn, hang and release predatory mites in stages, such as pasteurized blunt mites or courgette blunt mites, hang a bag of navel oranges per plant, hang on the branches in the trunk, prey on the corners of the mite bag or covered with small films, in order to prevent rain into the bag to drown the mites, 3 to 5 days before hanging and releasing the predator mites, should be sprayed to reduce the base number of insect mouths and then hang, optionally use avermectin or green Ying, etc. to prevent and control natural enemies, fruit safety, and not easy to produce resistance to drugs. After pressing the insect mouth base, hang the predator mite to achieve the purpose of treating the mite with mites, and pay attention not to the mite killing agent when spraying during the spray, otherwise the predator mite will be eliminated together, and the previous achievements will be abandoned.
After several years of observation, vigorously promote healthy cultivation technology, combined with the selection of green environmental protection pesticides, hanging bags to prey on mites, the implementation of mites to control mites, green environmental protection, improve quality, the effect is good.