Peach Tree Pest and Disease Control Methods and Technical Key Points
1. Note that peach trees are chlorine-sensitive crops. Applying chlorine-containing fertilizer easily causes root rot and yellowing leaves; in mild cases the tree vigor weakens, and in severe cases the plant dies. Therefore, do not apply chlorine-containing fertilizers. 2. Be careful about watering during the flowering period. Watering during flowering can easily lower soil temperature and reduce soil air content, affecting root growth and absorption, leading to...
Pests and Diseases and Their ControlThe diseases that cause major and widespread damage include peach leaf curl, anthracnose, brown rot, gummosis, and bacterial shot hole; the pests include red-necked longhorn beetle, aphids, globular scale insects, leafhoppers, peach fruit borer, slug moths, oriental fruit moth, peach aphid, mulberry white scale, and slug moths, among others. In southern China, bagging is often used for control.
1. Four diseases of peach: The pathogen of peach leaf curl overwinters on bud scales and bark, and infects leaves and new shoots before and after leaf expansion in early spring, causing them to deform, dry up, and drop, and it can also damage fruit. The control method is to spray 5 degrees Baume lime sulfur mixture when the peach buds are swollen but not yet opened; in severe cases, spray 0.3 degrees lime sulfur mixture again after leaf expansion, and at the same time promptly remove diseased leaves and shoots by hand and burn them to reduce the source of infection. Bacterial shot hole mostly occurs in spring and summer, causing leaf shot holes and drop. Control method: spray 1:1:100 Bordeaux mixture when buds sprout in early spring (green tip stage). When spraying, note that there must be a 7-10 day interval between the spraying period and that of lime sulfur mixture, and after leaf expansion it is advisable to switch to spraying 65% zineb 400-500 times dilution for control, so as to avoid phytotoxicity. Peach anthracnose damages fruit and twigs, and can occur from April to July; continuous rainy weather after flowering easily causes an outbreak of the disease. It can be controlled in combination with spraying for peach leaf curl and peach scab. Peach scab mainly damages fruit; spraying 0.3-0.4 degrees Baume lime sulfur mixture at the young fruit stage, or 25% carbendazim 400-500 times dilution, or 75% thiophanate 1000 times dilution, can all effectively control the disease.
2. Peach gummosis: It is a disease caused jointly by fungal infection and physiological factors, mainly damaging the trunk and main branches, causing gum exudation and weakening tree vigor. Heavy clay soil, excessive nitrogen fertilizer, continuous cropping, poor drainage, heavy summer pruning, and insect wounds can all aggravate gum exudation. Control method: mainly start with strengthening management and enhancing tree vigor, and do a good job of protecting the tree body.
3. Red-necked longhorn beetle: The larvae overwinter in tunnels bored in the trunk, damaging the trunk and root crown, weakening tree vigor or causing tree death. Control method: before adults lay eggs in late May, whitewash the trunk and the crotch parts of the main branches (the whitewash is made by mixing quicklime and water at a ratio of 1:3-5; adding a small amount of salt can increase adhesion, and adding a small amount of lime sulfur mixture residue can improve the insect-control effect), to reduce egg laying. At the same time, manually capture and kill adults. During the growing period, inspect the trunk frequently, and when larval damage is found, hook-kill or chemically kill them.
4. Peach fruit borer and oriental fruit moth: Both damage fruit, and the latter also damages peach shoots. During the peak egg-laying period, spray 50% fenitrothion emulsifiable concentrate 1000 times dilution to kill the larvae, and spray once more after 10-15 days. Bagging protection can also be carried out after spraying.
5. Peach aphid: It has many generations per year; as peach trees sprout, the eggs hatch and damage flowers and young leaves, then after June they move to other hosts to oversummer, and before leaf fall they migrate back to peach trees to lay eggs and overwinter. Control method: mainly focus on spraying 50% acephate emulsifiable concentrate 500-1000 times dilution, or 10% cypermethrin emulsifiable concentrate 1000-1300 times dilution during the peak hatching period of eggs in spring, both of which can achieve relatively good results. For peach aphids that have developed resistance to organophosphorus and pyrethroid pesticides, spraying 10% imidacloprid 3000-4000 times dilution is especially effective. When damage is severe, spray once more in autumn when peach aphids migrate back to peach trees.
6. Mulberry white scale: It has 2-3 generations per year in the Yangtze River basin. Early to mid-May is the peak hatching period; nymphs suck sap on branches and trunks, weakening tree vigor and in severe cases causing branch death, generally causing more damage on 2-3 year old branches. After the second instar, nymphs secrete wax and become resistant to pesticides. Control method: in addition to spraying 5 degrees Baume lime sulfur mixture before bud break as part of the control of other diseases, before the nymphs gather to cause damage and have not yet secreted wax, spray 0.3-0.4 degrees Baume lime sulfur mixture, or 90% trichlorfon 1000 times dilution, or 25% buprofezin 1000-1500 times dilution.
7. Leafhoppers: Adults overwinter in weeds and clods of soil; after peach trees sprout they climb the trees and damage young leaves, feeding on sap. In the early stage of leaf expansion and after full bloom, in combination with control of peach aphids, spray acephate and other pesticides. In addition, spraying 50% dichlorvos emulsifiable concentrate or 25% buprofezin 1000-1500 times dilution during the peak hatching period of the first generation eggs (about mid-to-late May) also has good results.