spring is ready to start, the temperature is rising, and the busy spring farming season will begin in most parts of the country. many fields of wheat will also enter the green period (late february to early march), missed before winter weeding, we must seize this wheat field weed period.
weeds in wheat fields are controlled during the green-back period (late february to early march), because the amount of weeds is large and the resistance is strong. it is necessary to increase the dosage of weeds in order to be effective, but it is also easy to cause pesticide damage, so special attention should be paid to the application of weeds.
selection of appropriate herbicides and formulations
the selection of herbicides for chemical weeding in wheat field should be determined according to the main weed species and the herbicide spectrum. when dicotyledon weeds and monocotyledon weeds occur together, several herbicides should be mixed according to a certain proportion to enlarge the herbicide spectrum and improve the weeding effect.
points for attention in drug application
1. drug application under suitable climatic conditions
most herbicides belong to positive temperature coefficient medicines. do not apply medicines below 6 c, from 10 a.m. to 3 p.m., and do not lower than this temperature for two days before and after herbicide application.
drug use in windy days can easily cause herbicide drift, and the effect is not good. it may also spread to greenhouse crops or other crops to cause herbicide damage, so it is forbidden to use herbicide in windy days. when using herbicides, if the soil is relatively dry, we should pay attention to increasing water consumption. if there is water accumulation, it will affect the efficacy of herbicides.
2. do not apply medicine when wheat is sick.
in recent years, wheat sheath blight, root rot, total rot and other seed-borne or soil-borne diseases frequently occur. before applying herbicides, determine whether the wheat seedlings are sick or not. if the wheat is sick, do not apply herbicides.
3. must be diluted twice.
some friends of the farmers plan to save the herbicide directly into the sprayer, and stir it with any branches to start spraying. this method of mixing medicines is very unscientific. because most of the herbicide products have their own auxiliaries, auxiliaries play a role of osmotic synergism. they are usually sticky. if they are directly poured into the sprayer, they may sink into the bottom of the barrel, resulting in the phenomenon that the auxiliaries wrapped with herbicides can not be opened.
the correct method of preparation is the two dilution method: first, mix the medicine with a small amount of water to form the mother liquor, then pour it into the sprayer with a certain amount of water, add the amount of water added to it, and stir it side by side, then dilute it to the required concentration.
do not pour water into the potion first, nor pour the medicine into the sprayer with plenty of water. so the wettable powder often floats on the water meter or forms a small block. the distribution is uneven, not only can not guarantee the effect, but also easily obstruct the nozzle when spraying. in addition, the liquid should be prepared with clean water.
4. avoid drug overdose
some peasant friends will spray herbicides in thicker and more places, or fear to waste the remaining herbicides to hit the back of the plot one after another, which can easily lead to herbicide damage. because herbicides are safe for wheat at normal concentrations, but if they are excessive, the wheat itself cannot decompose and is vulnerable to injury.
5. correct view on the phenomenon of herbicide yellow squatting seedlings
after some herbicides are applied, wheat will appear short-term yellowing of leaf tips, which is a normal phenomenon of squatting seedlings. generally, when wheat returns to green, it can recover itself. this phenomenon will not cause yield reduction, but can promote wheat production, prevent wheat from being affected by excessive vegetative growth and reproductive growth without undue worry.
tel: 86-371-60151181 fax: 86-371-60151077 mob: 86-15037157607 skype:andy17666 e-mail: ndsh@zzndsh.com address: 27f new mango,outer ring cbd,zhengzhou, henan,china 
