How to choose insecticide application timing and spraying site
1. Chlorpyrifos is prone to causing phytotoxicity when used during the melon seedling stage, and its use should also be avoided during the flowering period of some crops. 2. Pesticides containing triazophos are not suitable for use on fruit cane, as they easily cause phytotoxicity. 3. Because phoxim decomposes readily when exposed to light, its use should be avoided during the watermelon growing period and the seedling stage of radishes and leafy vegetables (even during the growing period...
To achieve the best insecticidal effect when using pesticides to control crop pests, in addition to selecting the right targeted agent and applying it at the appropriate time, special attention should also be paid to the timing and site of application.1. Based on climate characteristics and the day-and-night activity patterns of pests, choose a favorable time to apply the pesticide. The best times to apply pesticides are from 9 to 10 a.m. and after 4 p.m. This is because after 9 a.m. the dew on crop leaves has dried, and it is also the period when day-active pests are most active. Applying the pesticide at this time will not reduce the control effect because dew dilutes the spray solution, and it also allows pests to come into direct contact with the pesticide, increasing the chance of poisoning the pests. After 4 p.m., the sun leans to the west, light intensity decreases, and the temperature drops, and it is exactly the time when flying activity at dusk and night-active pests are about to emerge. Applying the pesticide at this time can apply the agent to the crops in advance, so that when pests come out to move or feed at dusk and at night they contact the toxic solution or ingest it and die from poisoning. At the same time, it can also avoid evaporation loss of the spray solution and failure due to photodegradation.
2. Based on the damaging part of the crop by the pest, select different agents and adopt different application methods to deliver the pesticide to the target. For example, for pests that damage the roots, pour the pesticide onto the roots or apply it in the sowing furrow; for pests that feed on the underside of leaves, spray the solution on the reverse side of the leaves; to control pink bollworm and cotton bollworm, spray the pesticide onto flower buds, green bolls, and the tips of clusters; to control stem borers that cause deadheart seedlings, broadcast poisoned soil; to control white heads, use spray or splash irrigation; to control rice planthoppers and rice leafhoppers, spray the solution onto the base of the rice plants; to control the tobacco cutworm, spray the solution onto flower buds and young pods. In addition, for concealed pests such as cotton aphids, red spiders, rice planthoppers, and rice leafhoppers, according to their piercing-sucking mouthpart feeding method, insecticides with strong systemic activity can be selected so that after absorption they are translocated by the plant to other parts, thereby achieving delivery of the pesticide to the target. Only by applying pesticides according to the pest and delivering the pesticide to the target can the vital point be hit, the effect of eliminating pests upon application be achieved, the pesticide play its best role, and an ideal insecticidal effect be obtained.