Latest tutorial on weeding techniques and methods for hardgrass in wheat cultivation
Hardgrass is a species under the genus Sclerochloa in the grass family (Poaceae). It is an annual or winter annual grass plant, reproducing by seed. The suitable emergence depth for seeds in soil is 0.12-2.4cm; depths exceeding 2.4cm make emergence difficult. It has strong tillering ability, with about 6 tillers per plant, and branches in pairs. It mostly grows in hills, alongside ditches and in fields, mainly harming dryland crops such as wheat. After wheat is sown in autumn, when the daily average temperature is 16-18°C, emergence peaks form within 3-5 days, that is, from wheat emergence to the 1-leaf stage.
Agricultural control
Implementing paddy-upland rotation is an important measure to reduce the occurrence of hardgrass. Generally, the paddy-upland rotation cycle is 3-4 years, which can reduce the severity of hardgrass damage. In fields with severe hardgrass occurrence, transplanted rapeseed or other broadleaf crops can be planted instead during autumn sowing, and when the daily average temperature stabilizes above 7°C during the hardgrass emergence peak, use 20-30 milliliters of 10.8% high-efficiency haloxyfop-R-methyl EC or 40-60 milliliters of 15% refined quizalofop-p-ethyl EC per mu, add 30-40 kilograms of water and spray.
Chemical control
1. Soil sealing. After sowing barley and wheat but before emergence, use 80 milliliters of 48% trifluralin EC plus 250 grams of 25% chlorotoluron WP per mu, add 40 kilograms of water and spray; the control effect is over 98%. When sowing barley and wheat, improve land preparation quality and sowing quality, and appropriately increase water usage when soil moisture is poor to improve the control effect.
2. Foliar treatment. For fields where soil sealing treatment was not carried out after sowing barley and wheat but before emergence, foliar treatment can be adopted. Before winter, from the 3-leaf stage to the tillering stage of barley and wheat, use 100 grams of 75% isoproturon WP per mu, add 40-50 kilograms of water and spray; the control effect reaches 93%. Alternatively, in the following spring before the jointing stage of barley and wheat, use 150 grams of 75% isoproturon WP per mu, add 50 kilograms of water and spray; the control effect is over 90%.