When is the best time to fight jatropha curcas and wild wheat? What problems should we pay attention to?

The occurrence period of weed Aegilops tauschii and common wheat in wheat field can be roughly divided into two peak periods, before winter and in spring, and the amount of seedling emergence varies with climatic conditions. In the application stage, according to the peak characteristics of Aegilops tauschii and wild wheat, appropriate chemical control should be carried out before heading of winter wheat or spring wheat, and the application effect is the best. From the cost analysis report of weeding, it is less before than after, because of the problem of dosage. At present, the general specifications and models of post-emergence herbicides on the market are one set per acre (with glass bottles and bags). If you look at its application, you will find that,

Weeds are used at the stage of 2-4 leaves, that is, the dosage is just after the weeds germinate (years ago), but when the weeds break through 5-6 leaves or even more years later, in order to achieve the actual effect of weeding, the dosage will be increased accordingly. Years ago, a set of medicine could only be used for 7-8 points, which virtually increased the cost of taking medicine. Generally speaking, wild wheat will germinate with weeds, but when the seeds are all over the shallow soil layer, they will germinate quickly and densely, and when the seeds are all over the deep soil layer,

It will germinate slowly and last for a long time, so in general, weeds such as wild wheat will germinate at two peak periods, that is, before winter and when the wheat turns green after the year. However, for fields with early planting and wet soil, wild wheat will germinate before winter, so chemical control should be carried out before winter to basically complete germination. Weeds are small and resistance is poor, so it is easier to apply pesticides. Even if the effect is not good, it can be made up after the year. If not only there are many weeds, but also the grass is old and the temperature changes like a child's face,

Idealized chemical control is generally difficult to achieve practical results, and even causes fertilizer damage, which is harmful to the total output. The actual effect of weeding after 3 leaves of wheat was basically completed, and the mechanism was fresh and tender. Generally speaking, it is most appropriate to take medicine in the first ten days of 1 1, that is, more than 40 days after wheat sowing. At this time, the amount of weeds excavated accounts for more than 90% of the whole growth period. In order to ensure the control effect, it is necessary to use the medicine in sunny days with the temperature above 10℃ and when the soil layer is wet. If the temperature is too low (below 6℃), weeds will die slowly.