Aphids are one of the main pests of peach trees, if the early control measures are not in place in time, resulting in peach aphid outbreaks, it will lead to poor growth of peach trees and even fruit drops.
Through the investigation of the harm of taoyuan aphids in recent years, it was found that most of the peach orchards did not control aphids in place, the early stage was not prevented, and the medicine could not be cured in the middle and late stages, resulting in a large number of curls and fall off the peach tree leaves, resulting in serious occurrence of peach orchard aphids year after year, which seriously affected the normal growth of peach trees, reduced yield, poor differentiation of flower buds, low commodity fruit rate, increased production costs, and greatly reduced the economic benefits of fruit farmers. The following author will summarize the occurrence of aphids and the key period of control, hoping to help fruit farmers in peach orchard production.
First, the occurrence of taoyuan aphids
Peach aphids occur in about 10 to 30 generations per year, and the phenomenon of generation overlap is prominent. Female aphids are able to reproduce at birth, that is, parthenogenesis, so aphids reproduce particularly quickly. Peach aphids overwinter at the axillary buds of peach tree branches with eggs, and begin to hatch when the buds are loose and the buds are expanded and red in the coming year, initially harmful on the buds, transferred to the back of the leaves after leaf spreading, and the peak period is from mid-to-late April to early to mid-May. When the wheat is ripe, some winged aphids are transferred to weeds and vegetables, and by October, winged aphids will fly in the peach orchard and spawn and overwinter.
Second, the characteristics of the hazard
Aphids are clustered on the back of the treetops, young shoots and young leaves when the peach tree germinates and spreads leaves, so that the damaged part appears black, red and yellow small spots, and the leaves gradually turn white and twist to the back, rolling into a spiral, causing leaf fall, new shoots can not grow, affecting yield and flower bud formation, weakening the tree potential. Aphids harm newly opened flowers, sting the nutrients of the cotyledon, affect fruit set, cause deformed fruits, and reduce yields. The honeydew excreted by aphids pollutes the leaves and branches, hindering the physiological role of peach trees, often causing soot disease, accelerating early leaf fall, and affecting peach tree growth.
3. Prevention and control measures
We have mastered the occurrence law and harmful characteristics of aphids, so we must seize the critical period and carry out targeted scientific and effective prevention and control. Specific prevention and control measures and key periods are as follows:
1. Qingyuan. Aphid overwintering eggs are mostly on the outer branches, peach farmers in the pruning to remove autumn shoots, short spring shoots, remove the pruning branches under the tree, bring out the peach orchard, reduce the number of insect eggs in the garden overwintering base; in early spring, when the buds of peach trees germinate, the whole garden sprays 3 to 5 baumedo stone sulfur compounds for clearing the garden.
2. Carry out physical prevention and control. Aphids are yellowing, and peach farmers can hang yellow armyworm plates on the branches of peach trees with fewer leaves in peach orchards to control aphid damage and reduce the number of insect mouths.
3. Carry out biological control and protect the natural enemies of pests. The natural enemies of peach tree aphids mainly include Chinese grasshoppers, seven-star ladybirds, aphid-eating flies, parasitic wasps, etc. In the case that natural enemies can inhibit aphids, peach farmers can minimize the number of sprays.
4. Chemical control in critical periods.
The first key control period: peach blossom bell flowering period, this is the peach aphid eggs hatching larvae period, this time spraying can be very effective in killing peach aphid larvae, reducing the insect population base. If you miss this period, the aphid mouth base increases, and then carry out drug control, it is necessary to take drugs many times, increase the cost, and the control effect is very poor.
The second key control period: when the peach blossom falls 80%, that is, most of the flowers are fluttering petals, and a small number of flowers are blooming, this time must be sprayed in time for prevention and control, mainly to prevent and control the aphids that leaked in the first critical period, do not wait until all the flowers are gone, and after the fall of the aphids have erupted into disasters, the leaves are curled, and the control effect is very poor.
The third key control period: from mid-to-late September to early November in autumn, according to the harm law of aphids, aphids will fly to the peach orchard around October to lay eggs and overwinter. Therefore, this period is a critical period for the control of aphids, and at the same time, combined with the control of diseases and insect pests in autumn, it must be equipped with aphid-killing agents to effectively kill the migrating aphids and reduce the egg laying base and the wintering egg base.
4. Recommend the agent
Due to the wide range of aphid host plants, short development period, strong reproductive capacity, production for a long time mainly rely on chemical pesticides for control, has developed resistance to a variety of pesticides, fruit farmers should pay attention to the need to use a variety of agents alternately, so as to avoid aphids to produce resistance. Spray pesticides should be carefully and uniformly, while the interval time is 7 to 10 days, in order to improve the effect, you can add a certain dose of adhesives such as silicones to the liquid.
From the experience of preventing and controlling aphids in recent years, the effect of the commonly used drugs of acetamiprid, imidacloprid and prazidazone has become worse and worse, and the resistance of aphids is getting stronger and stronger. Through the practical application of the following drugs, the control effect of aphids is better:
Ethyl spirant ester has a two-way aspiratory conductivity, moving up and down throughout the plant, reaching the foliage and bark, pests on the bark, preventing the growth of aphid larvae, with a long duration of effectiveness, providing effective control for up to 8 weeks. If combined with thiamethoxine spraying, the control effect is better.
Flufenalazolenitrile is currently a good agent for the control of peach tree aphids, with the dual effect of touch killing and internal suction, aphid killing is efficient, long effective, rain-resistant erosion, a growth period of up to two times.
Thiamethoxine has the effects of touch killing, gastric toxicity, systemic suction, fast action, long effectiveness, wide range of insecticidal, etc., and can simultaneously control aphids, leafhoppers, whiteflies, scarab larvae, nematodes, ground beetles, leafminer moths and other pests.
There are also many compounds on the market, and the effect is good. Such as fluoridine acetamiprid, pyrithiazine, ethyl spironium + furazine, ethyl spironium + pyrizole, ethyl spironium + thiamethoxazine, enidine pyrazone, etc., we can choose the agent according to the specific situation.
Author: Zhu Zhenli