Field hazard symptom identification and green prevention and control technology of leafhoppers on blueberries in Nangao Bush
Dong Kefeng, Jiang Huitie
Nangaocong blueberry is the preferred variety for planting blueberries in the mixed evergreen and deciduous fruit tree areas of China (mainly in the Yunnan-Guichuan area), which mostly have the advantages of vigorous growth, large leaves, and large fruits suitable for fresh fruits. When the author conducted technical guidance on the company's customer base, he found that some blueberry bases are vulnerable to leafhoppers in the summer and autumn, which affects the growth of blueberry trees and causes the following year's blueberry production to decrease. To this end, the identification of field hazard symptoms and green prevention and control methods of leafhoppers are introduced as follows:
1 Identification of field hazard symptoms of leafhoppers
Leafhoppers are pests of the family Pterodactyceae and are small and cicada-like. Leafhoppers in the field are polyzoan, with nymphs (figure 1) and adults (figure 2) stabbing blueberry stems and leaves, the affected leaves become smaller, deformed, and curled, needle-like spots are visible on the back of the leaves, some of the new leaf tips in the field are dried up (figure 3) and the adults are harmed by spawning, and the blueberry epidermis is cut into crescent-shaped cracks with an egg layer during egg laying, and there are obvious brown patches on the young branches, resulting in shorter branches and dryness of the tender tips of new branches (figure 4). In the production, the new leaves of blueberries dry up, which is easily mistaken for physiological diseases or other diseases, resulting in missed leafhopper control periods. The damage to the branches and leaves is obvious, affecting the normal growth of the plant and the formation of flower buds (figure 5), while spreading viral diseases. When investigating the hazards of leafhoppers, wave the plant in the field in the afternoon to see if the take-off leafhoppers are visible. During field investigation, it is found that the leaf tip and leaf margin of the field blueberries are gradually curled, forming a "scorch head", "scorch edge", and continuously expanding to the whole leaf.
Figure 1 Nymphs
Figure 2 Adult worms
Fig. 3 The tip of the affected leaf is dried up
Figure 4 Branches injured
Fig. 5 Leaf damage
2 Blueberry leafhopper green control technology
2.1 Agronomic measures
Clean up the weeds in and around the blueberry orchard, prune the dead branches and destroy them in a concentrated manner.
2.2 Booby Traps
One is to use the yellow plate sticking, hanging 20 cm × 30 cm yellow armyworm board on the top of the plant, with 20 sheets per acre; the second is to use the phototropism of the adult leafhopper to place a black light lamp for booby traps.
South high bush blueberries
2.3 Anti-migration nymphs
Spray permethrin pesticides around and over weeds around the blueberry orchard during the adult season to eliminate the hatching nymphs and prevent migration to the blueberry trees.
2.4 Pharmaceutical control
After the blueberry picking is completed in summer and autumn, the optional green food Class A production allows medication to be used to control the leafhopper during the occurrence period.
2.4.1 The appropriate period for control Is the appropriate period for control when there are 20 blinds in summer and autumn or when nymphs in the field account for 80% of the total insect population.
2.4.2 Control agents The preferred agent for the control of leafhoppers is 25% thiazide (chlorpheniramine) wettable powder 1 500 times liquid, and 20% furoxamin wettable powder 1 500 times liquid can also be used alternately; or 20% leafhopper dispersion 2 000 times liquid, 5% bifenthrin emulsion 2 000 times liquid, etc. Pay attention to the uniform order of medication throughout the park until the number of leafhoppers is reduced below the control index.