小麦秸秆及浸提液对4种谷田杂草的化感防除作用

为探究利用小麦秸秆及浸提液对谷田杂草的化感作用。室内试验设置小麦秸秆浸提液1(T₁)、2(T₂)、10(T₃)、100 g/L(T₄)共4个处理和对照(CK₁,0 g/L),测定对稗草(Echinochloa crusgalli(L.) Beauv)、反枝苋(Amaranthus retroflexus L.)、狗尾草(Setaria viridis(L.) Beauv)、藜(Chenopodium album L.)4种杂草种子发芽率、根长、芽长、发芽化感指数、根长化感指数、芽长化感指数、综合化感指数的影响；田间试验设置0(CK₂)、2 250(W₁)、4 500(W₂)、9 000 kg/hm²(W₃)4种小麦秸秆覆盖还田量，50%(P₁)、70%(P₂)、100%(P₃)3种地膜覆盖遮光处理，测定4...

Allelopathic control effects of wheat straw and extracts on four kinds of weeds in foxtail millet field

In order to explore the allelopathy of wheat straw and extract on weeds in foxtail millet fields, four treatments of wheat straw aqueous extract 1(T₁), 2(T₂), 10(T₃), 100 g/L(T₄)and control(CK₁, 0 g/L)were set up to determine their effects on seed germination rate, root length, bud length, germination allelopathy index, root length allelopathy index, bud length allelopathy index and comprehensive allelopathy index of four weeds Echinochloa crusgalli (L. )Beauv, Amaranthus retroflexus L. , Setaria viridis(L. )Beauv and Chenopodium album L. In the field experiment, four wheat straw mulching treatments 0(CK), 2 250(W₁), 4 500(W₂), 9 000 kg/hm²(W₃)and three plastic film mulching treatments 50%(P₁), 70%(P₂), 100%(P₃)were set up to measure the number, density, coverage and control effect of 4 kinds of weeds in the field. The results show that the water extract of wheat straw treated with T₄ had the highest allelopathic index and the strongest allelopathic inhibition effect on the seeds of four kinds of weeds in the foxtail millet field. The inhibition effect on the seed germination of four kinds of weeds from high to low was as follows: C. album>A. retroflexus>S. viridis>E. crusgalli. And the allelopathy index were respectively -0. 85, -0. 77, -0. 71 and -0. 34; T₁ showed allelopathic promoting effect on the germination of weed seeds of C. album, S. viridis and A. retroflexus, and the promoting effect from strong to weak was as follows: S. viridis(0. 14)>C. album(0. 05)>A. retroflexus(0. 02). And the allelopathic inhibiting effect was discovered on the germination of E. crusgalli seeds; T₂ showed allelopathic promotion on the bud length of four weeds; T₃ showed allelopathic inhibition on root length of S. viridis and E. crusgalli and allelopathic promotion on C. album and A. retroflexus; the allelopathic effects of T₄ on four kinds of cereal weeds from high to low was: S. viridis>A. retroflexus>C. album>E. crusgalli. Compared with the treatment without straw mulch, the occurrence density of C. album decreased respectively by 69. 39%, 64. 29% and 43. 34% in W₃(9 000 kg/hm²)after 3 times of moderate rain for five days, and the total coverage of weeds decreased by 22. 04%, 41. 98% and 12. 49% respectively. With the extension of straw mulching time, the number of rainfall increased, the density of weeds decreased first and then increased, and the coverage of weeds gradually decreased. With the increase of straw coverage from 2 250 to 9 000 kg/hm², the control effect of weed plants increased from 20% to more than 60%. Therefore, the 100 g/L extract of wheat straw has the most significant inhibition effect on the seed germination, root length and bud length of four weeds, and 9 000 kg/hm² wheat straw mulch can be used to control weeds in foxtail millet fields.