Effect of metribuzin, butachlor and chlorimuron-ethyl on amino acid and protein formation in wheat and maize seedlings

Application of the recommended field dose of metribuzin, butachlor and chlorimuron-ethyl to 10-days-old wheat and maize seedlings differentially reduced shoot fresh and dry weights during the following 16 days. Metribuzin was the most reductive while butachlor was the least. The herbicides slightly affected the activities of nitrate reductase (NR, EC 1.6.6.1) and nitrite reductase (NiR, EC 1.7.7.1) but greatly inhibited glutamine synthetase (GS, EC 6.3.1.2) and glutamate synthase (GOGAT, EC 1.4.7.1) activities. Meanwhile, there were significant accumulations of ammonia and soluble-N accompanied by diminutions in total-N and protein contents; metribuzin exerted the greatest changes. Additionally, aliphatic, aromatic and total amino acids in both species were mostly elevated by the three herbicides; however, valine, leucine and isoleucine were decreased by only chlorimuron-ethyl. These results could conclude that herbicides, particularly metribuzin, cause a shortage in ammonia assimilation and subsequently a decrease in protein formation. Moreover, the elevation of soluble-N and amino acids appeared to result from breakdown of the pre-existing protein, a state that seemed consistent in seedlings treated with metribuzin and, to some extent chlorimuron-ethyl but recovered in those treated with butachlor.     

越冬之星苜蓿苗期除草剂筛选及杂草防除

[目的]筛选出对越冬之星苜蓿苗期生长安全的除草剂,并确定其防除效果,为苜蓿田杂草的防治提供依据。[方法]选用9种除草剂对苗期越冬之星苜蓿田进行除草剂筛选及杂草防除试验。[结果]不同除草剂对其生长发育、防除效果及增产效果都有一定影响,影响程度因除草剂种类与剂量不同存在差异,金普施特的综合表现最佳,能够同时防除大部分阔叶杂草和单子叶杂草。[结论]金普施特可在越冬之星苜蓿田大面积生产中推广应用。     

佳木斯地区肇东苜蓿田土壤处理除草剂的筛选

[目的]筛选佳木斯地区肇东苜蓿无药害除草剂品种和使用方法。[方法]通过土壤处理除草剂小区试验研究6种除草剂处理对肇东苜蓿分枝期苗情和草情的影响。[结果]6种土壤处理除草剂对阔叶杂草均有抑制或杀灭作用,对禾本科杂草也有一定防效。对肇东苜蓿无药害的药剂处理有75%阔叶散悬浮剂播后苗前喷雾,药害较轻的有5%普施特水剂播后苗前喷雾。对肇东苜蓿干草产量影响较小的为5%普施特水剂播后菌前喷雾和75%阔叶散悬浮剂播后菌前喷雾。[结论]肇东苜蓿无药害除草剂品种和使用方法推荐5%普施特水剂播后苗前喷雾。     

4％烟嘧磺隆减量对玉米田杂草防效及玉米产量的影响

[目的]评价4%烟嘧磺隆悬浮剂减量施用在玉米田杂草防治上的可行性。[方法]以郑单958为试验品种,研究1 500 m L/hm~24%烟嘧磺隆、750 m L/hm~24%烟嘧磺隆、750 m L/hm~24%烟嘧磺隆+增效剂A(99%甲酯化大豆油)、750 m L/hm~24%烟嘧磺隆+增效剂B(Silwet 408)4个除草剂减量施用对玉米田杂草防效及玉米产量的影响。[结果]添加增效剂能明显提高烟嘧磺隆除草剂的防效,较正常剂量或减量50%单施烟嘧磺隆处理药效提高了9.6%~27.0%,且施药后28 d药效降幅也最小,增效剂Silwet 408对玉米的安全性明显优于99%甲酯化大豆油,且防效好,玉米产量较不除草对照提高了16.6%。[结论]试验结果为玉米田杂草治理和化学除草剂减量使用提供了理论依据。     

几种常用除草剂对家蚕生长发育的影响

[目的]探讨4种农田常用除草剂对家蚕生长发育和产茧的影响,筛选适宜的桑园除草剂。[方法]采用毒叶添食法研究目前常用除草剂莠去津、烟嘧磺隆、硝磺草酮和草甘膦对家蚕生长发育及茧质的影响。[结果]莠去津对家蚕的毒性最大,取食毒叶第7天全部死亡;烟嘧磺隆对家蚕的毒性也较大,家蚕的死亡率高达80%,虽然有部分蚕能够泌丝结茧,但所结茧的茧质极差;硝磺草酮和草甘膦毒性较小,家蚕的存活率超过70%,大部分都能泌丝结茧;硝磺草酮和草甘膦低浓度处理基本不影响茧质,而高浓度处理降低了家蚕茧的全茧量和茧层量,对茧长和茧幅基本无影响。[结论]莠去津和烟嘧磺隆对家蚕毒性大,不适宜用于桑园除草;低浓度硝磺草酮和草甘膦对家蚕相对安全。     

几种不同茎叶处理除草剂对谷子的安全性研究

采用随机完全区组试验设计,在大田条件下研究了百草敌、2甲4氯、2,4-D丁酯对谷子形态指标及生理代谢的影响,探讨了除草剂对谷子生长的安全性。结果表明,3种药剂中,百草敌对谷子形态指标和生理指标的抑制率均最小,对谷子产量的影响未达显著水平,对谷子较安全;2,4-D丁酯对谷子的安全性最差,对谷子各项形态指标和生理指标的抑制率均最大,对谷子产量有显著的影响;2甲4氯对谷子的安全性居中。由此可见,百草敌可作为谷子田较理想的除草剂。     

Evaluation of some weed control treatments for long season weed control in maize (Zea mays L.) under zero and minimum tillage at Samaru, in Nigeria

The effect of weed control treatments for long season control of weeds in maize under zero and minimum tillage was evaluated at Samara in northern Nigeria. Among the weed control treatments evaluated, soil ridging plus application of either 2,4-D or atrazine at 1.5 kg a.i/ha performed well as they effectively controlled weeds and resulted in better growth and a grain yield that was comparable to the hand weed control. Maize production under minimum tillage was better than under zero tillage.     

康县牡丹园草的种类及其除草剂的选择

牡丹在我国有着很大的药用价值和观赏价值。合理地除去牡丹园的杂草让牡丹幼苗更好地生长是一项重要的工作。对康县牡丹园的杂草种类进行调研和分类,有针对性地选择相关除草剂,具有一定的除草功效。     

Effect of some Herbicides on Oil Seed Rape (Brassica Napus L.) and Associated Weeds

Two field experiments were conducted during 1984/1985 and 1985/1986 seasons to study the effect of Alachlor, Metolachlor, Pendimethalin, Diphenamid, CGA 10832 and Oxadiazon as pre-emergence herbicides and EPTC as presowing herbicide at two doses as well as hand-hoeing treatment on weed spread and rapeseed yield under Egyptian conditions. All the tested herbicides except "Oxadiazon" gave satisfactorily good annual grass weed control up to harvest time. While, Oxadiazon and Diphenamid at both doses controlled adequately the growth of annual broad-leaved weeds. The highest rapeseed yield was achieved under the application of Metolachlor at 2.4 and 3.6, Pendimethalin at 1.8, Diphenamid at 1.8, CGA 10832 at 2.4 and Oxadiazon at 1.2 kg a.i./ha. While, Pendimethalin at 2.4, Diphenamid at 2.4, CGA 10832 at 3.6, Oxadiazon at 1.8 and EPTC at 5.5 kg a.i./ha exhibited an obvious phytotoxic effect on rapeseed plants.     

Assessment of the effects of the photosynthesis-inhibiting herbicides Diuron,DCMU, metamitron and metribuzin on growth and nitrogenase activity of Nostoc muscorum and a new cyanobacterial isolate,strain G4

Summary The influence of the photosynthesis-inhibiting herbicides Diuron, DCMU, metamitron, and metribuzin on growth and nitrogenase activity of Nostoc muscorum and a new cyanobacterial isolate, strain G4, was studied. The experiments were performed under N₂-fixing photoautotrophic conditions. Both cyanobacteria showed a high degree of tolerance towards the herbicides tested. In the presence of metamitron (35, 70, and 140 ppm) and metribuzin (7, 14, 35, and 70 ppm) strain G4 proliferated as well as the control culture. Metamitron and metribuzin had no influence on the nitrogenase synthesis of strain G4 and N. muscorum. When treated with 1 M DCMU, strain G4 and N. muscorum showed partial inhibition for the first few days, but entirely recovered during succeeding incubation. In the presence of 10 ppm Diuron, N. muscorum and strain G4, compared to the control, showed 30% and 80% nitrogenase activity, respectively.