How to improve the using effect of pesticide?
For a long time, famers have reflected a lot that the effect of chemical pesticide is very poor when it is used in preventing crop diseases and pests, which may be caused by many factors. Due to the poor using effect of pesticide, huge waste and loss that caused by unscientific and improper using, it is very necessary to popularize the pesticide knowledge so as to strengthen the publicity of chemical pesticide using technology and improve the using effect of chemical pesticide. Below some problems that put forward by plantchemical.com should be paid much attention to.
As different kinds of germs, pests, weeds and other harmful organisms will have different body structures, physiological functions and living habits, even a same kind of drug will have different pesticide effect on different prevention objects, besides, the same kind of prevention object will also have different resistance on different kinds of drugs. In addition, the sensitivity and resistance to drug will also vary in different developmental stages of the same kind of germ, pest and weed. For example, although triazophos EC is effective in preventing dry sheath of early rice that caused by striped rice borer, it will be easy to cause phytotoxcity on early rice, therefore, other kinds of effective and safe pesticides should be used. Famers should choose pesticide varieties according to different prevention objects and crops. Meanwhile, they should clearly understand the physiological mechanism and damage characteristics of the prevention objects as well as consider the crop varieties and growth stage. At present, as many famers do not clearly understand how to correctly choose pesticides, some of them will kill pests by using bactericide, while the other of them will kill germs by using insecticide or even using highly toxic pesticide or pesticide that has been beyond the warranty period, which will have impact on the preventing effect and economic benefit. Before choosing and using the pesticide, we should consider whether it will cause harmful effect on the crops. If the pesticide will inhibit growth or cause phytotoxcity on the crops, it cannot be used. For example, carbaryl cannot be used on melons and amobam cannot be used on beans; dimethoate and rosin mixture can be used in preventing young scale insect of orange, however, in order to prevent aged scale insects, other kinds of pesticides should be used.
Master the most appropriate controlling optimum period
It is the key to improve the using effect of farming pesticides by correctly mastering the controlling optimum period. In order to ensure the control effect and avoid the abuse of pesticide, chemical control method should be used in the optimum period, besides, the control object fields should be confirmed by checking the density of plant diseases and insect pests under the guidance of local agricultural technology department; meanwhile, the specific control time should also be formulated by checking the development progress of pests. This can be called “two checking and two confirmations” in chemical control. Certainly, the agricultural technology department should issue the pest control information to the farmers in time according to the survey results. If the conditions are permitted, they can also use unifying pest control method in the optimum period, thus they can achieve obvious control effect. After the controlling optimum period is confirmed, they should also confirm the most appropriate medication time so as to achieve best pesticide effect by referring to the living habits of different kinds of diseases and insect pests. For example, as cabbage butterfly, sylepta derogata fabricius, yellow cotton moth and rice grasshopper will go out for activities in the daytime when there is plenty of light as well as most of the tryporyza incertulas egg mass will hatch in forenoon, pesticides should be used after 9 a.m., thus it can kill the pests more effectively; as some pests such as cutworm and snail will go out for activities after 5 p.m., by spraying the pesticide at this time, pests will have more chances of contacting with the pesticides or will die after eating the toxic blade. Meanwhile, it also can avoid liquid evaporation and pesticide photolysis. However, as many farmers do not clearly understand these kinds of technologies, it will cause poor pest control effect.
Using the pesticides according to the environmental conditions
The effect of pesticides used in farming will largely depend on the environmental conditions, such as object conditions, field management conditions and the surrounding crop varieties. Especially when using mist spray, powder spraying, fumigation and other pesticide application technologies, it will be closely related with local environmental conditions. For example, pesticides can be used at 8-9 a.m. in preventing pests that appear in the daytime, as dew will all evaporate at this time and the temperature will not be too high, besides, pests will eat and go out for activities more frequently. Therefore, pesticides will not be diluted by dews or dissolved by the high temperature, which can increase the drug eating and contact chances. In order to prevent pests that appear in the nighttime, pesticides can be sprayed at 5-6 p.m., as there will be no strong light or high temperature at this time, besides, pests are about to go out for activities, therefore, it will increase the chances of killing pests. Some chemical pesticides will have close relationships with weather conditions when being used, for example, bifenthrin can only be used in spring and autumn when the temperature is low, however, pirimor and other pesticides can only have good effect when they are used at more than 20 degrees Celsius. For another example, phoxim and trifluralin will be easy to dissolve when they are exposed in the light. Therefore, they should be stored in shade place and should be sprayed at dusk or cloudy days. After soil treatment, it should be covered with soil so as to avoid the decomposition and extend the effective period. When preventing rice stem borer, rice planthopper and other pests, 3-5 cm water layer should be kept in the field, thus the pests will have more chances to contact with the pesticides when they move up from the root. Besides, pesticides that fell into water will transmit from the bottom part to the upper part of rice plant through the diffusion of rice stem leaf interval, thus it can expand the insecticidal range. When the systemic pesticide is absorbed by rice roots, it also can be transmitted to other parts of rice plant and kill pests.
Pay attention to alternate and mixed use of pesticides
If some kind of chemical pesticide is used for a long time, it will be easy to cause drug resistance on the pests. Therefore, when using pesticides, farmers should alternatively use them by selecting different kinds of mechanisms or properly use them according to the physical and chemical properties. Thus it will not only extend control range and improve control effect, but also can delay the resistance to pests. However, when mixing pesticides, below some points should be paid attention to: a. if the pesticide effect will be improved or will not influence each other after mixing, these kinds of pesticides can be mixed, while if the pesticide effect is reduced rapidly or lose effect, they cannot be mixed for sure, besides, if the pesticide effect is reduced after a period of time of mixing, they should be mixed and used at the same time; b. if the toxicity is increased or it will cause phytotoxicity on the crops after mixing, they also cannot be mixed; c. pay attention to the antagonism, for example, after mixing, bentazone and sethoxydim will reduce the control effect on grassy weed due to antagonism; by mixing validamycin and blasticidin, it will reduce the control effect of validamycin on rice sheath blight.