河北中部麦田杂草的发生规律及其化学防除技术研究

Studies on the Occurrence Pattern and Chemical Control Techniques of Weeds in Winter Wheat Fields in Middle Area of Hebei

Authors have studied the occurrence pattern and chemical control techniques of weeds in winter wheat fields in middle area of Hebei in 1987-1988. Results showed that there are three batches weeds occurred in the fields. The first batch of weeds occurred before winter, there are Descurainia sophia(L.), schar and capsella aursa-pastoris(L.) Medic. The second batch of weeds occurred at winter wheat 4 leaf stage, there are chenopdium album L. , Cephalanoplos setosum(Willd.) kitam, Calystegia hederacea Wall. , Polygonum aviculare L. , Chenopodimu setotinum and Convolvulus arvensis L. , The third batch of weeds occurred at winter wheat B leaf stage, there are Chenopdium album L. Chenopodimu serotinum L. also. The most dominant population are Deseurainia sophia (L.) schur single dominant population, Chenopdium album L. single dominant population, Descurainia sophia (L.) Schur and Capsella bursa-pastoris (L.) Medic double dominant population, Descurainia sophia(L.)Schur and Capselja bu rsa-pastoris(L.)Medic and Chenopdium album L. manifold dominant popula tiim. According to the occurrence pattern of the weeds in fields, we suggest that using two chemical control system to contorl weeds. A system: usingdicamba(Banvel)+2.4-D ester(200+375g. (a.i.)/ha)or dicamba+MCPA-Na (200+570g. (a.i)/ha) at winter wheat four leaf stage spraying provided Chenopdium album L. single dominant population occurred in fields. B system: Using 2.4-D ester (750g. (a.i.)/ha)or MCPA-Na(1125g. (a.i.)/ha) at winter wheat three leaf stage, and using dicamba+2.4-D ester (200+375g.(a.i.)/ha) or dicanba+MCPA-Na(200+570 g.(a.i.)/ha) at winter wheat fire leaf stage twice spraying provided Descurainia sophia (1.)Schur single dominant population, Descurainia sophia (1.)Schur and Capsella bursa-pastrois(L.)Medic double dominant population, or Descurainia sophia (L.) Schur and cheropium album L. manifold dominant po pulation occurred in fields.