Deferred Seeding of Blackgram (Phaseolus mungo L.) in Rice (Oryza sativa L.) Field on Yield Advantages and Smothering of Weeds

Field experiments were conducted at Agricultural Experimental Farm, Giridih, Jharkhand, during the kharif (wet) seasons of consecutive four years (1998–2001) to study the effect of staggered seeding of blackgram (Phaseolus mungo L.) in rice field as a cereal–legume intercropping system and to minimize the degree of competition between the crop species to avoid yield damage, and at the same time to create a high level of competition by the intercrops to suppress the weeds. Intercropping systems were assessed on the basis of land equivalent ratio, relative crowding coefficient, aggressivity, actual yield loss, monetary advantage, etc. Intercropping reduced the yield of component crops when compared with respective pure stands. However, deferred seeding of blackgram in rice (30 cm) after one weeding was most remunerative system and registered maximum rice-equivalent yield (2711 kg ha⁻¹). Rice–blackgram (20 cm) intercropping system was very effective for weed smothering among unweeded intercropping treatments. In conclusion, deferred seeding of blackgram in rice field (30 cm) with one weeding may be recommended for better yield, weed suppression and better economics in the eastern plateau region of India.     

不同除草剂对蚕豆田间杂草及蚕豆生长和根瘤的影响

为筛选适于蚕豆田间的高效、安全除草剂,以四川省主栽品种‘成胡15号’为试验材料,选用7种除草剂（2种苗前、5种苗后除草剂）,设人工除草和等量清水喷雾2种对照,调查秋蚕豆田杂草种类,研究不同除草剂对蚕豆田杂草的防除效果、对蚕豆根瘤生长和蚕豆农艺性状及产量等的影响。结果表明：（1）蚕豆田间杂草共13科42种,最主要的是菊科、禾本科、苋科、蓼科和十字花科。（2）33%除草通、960 g/L精异丙甲草胺和15%精喹禾灵+48%灭草松3种处理能有效防治杂草,防效均为3级。（3）施用除草剂和人工除草均会影响蚕豆根瘤生长,15%精喹禾灵和15%精喹禾灵+48%灭草松处理均能提高根瘤鲜重和干重。（4）33%除草通处理增加蚕豆单株粒数效果显著,960 g/L精异丙甲草胺和15%精喹禾灵+48%灭草松2种处理可显著增加蚕豆有效分枝、单株荚数和单株粒数,15%精喹禾灵显著提高蚕豆株高。33%除草通、5%精禾草克和15%精喹禾灵+48%灭草松3种处理表现出显著增产作用。结合草害防效、根瘤生长、蚕豆农艺性状及产量结果,在本试验条件下,秋播蚕豆田除草剂推荐苗前施用33%除草通、苗后采用15%精喹禾灵+48%灭草松混合处理。     

两种除草剂对云南秋播苦荞田除草效应及其产量的影响

为了探讨除草剂对云南秋播苦荞田的防除效果、苦荞的安全性和产量的影响,以‘云荞1号’为材料,对云南秋播苦荞田进行不除草、人工除草、化学除草(金都尔、乙草胺)苗前土壤喷雾4个处理。试验结果表明,金都尔和乙草胺除草剂对秋播荞麦田的杂草有较好的防除效果,并且金都尔除草剂对阔叶杂草的防除效果大于禾本科杂草的防除效果,而乙草胺除草剂对禾本科杂草的防除效果大于阔叶杂草的防除效果；但两种除草剂对苦荞的出苗和幼苗生长都有一定的抑制作用,并且严重影响苦荞产量。因此在生产中,以阔叶杂草为主的苦荞田建议使用金都尔除草剂、以禾本科杂草为主的苦荞田建议使用乙草胺除草剂,但尚需进一步研究防除效果好又不影响产量的适合苦荞田除草剂浓度的筛选。     

Influence of Repeated Application of Herbicides on Weed Succession and Yield of Rice Based Cropping System in India

Field experiments were conducted to determine the effect of continuous application of herbicide on weed growth and yield of rice-rice-pulse cropping sequence over nine cropping seasons. The dominant weed species were Marselia quadrifolia, Echinochloa crus-galli, Cyperus difformis and Monochoria vaginalis. In hand weeded plots M. quadrifolia and the annual grass E. crus-galli were dominant in the early crops; E. crus-galli dominated in the later crops, with a shift to M. vaginalis in dicots. Annual application of herbicides caused a population shift from dicots to monocots, particularly grasses. Among grasses, Leptochloa chinensis , a difficult weed to control replaced dicots and reduced E. crus-galli. Combined chemical treatment and manual weeding as well as manual weeding controlled the weed growth and maintained the yield of rice throughout the period of study.     

冬油菜苗期化学除草效果和经济效益研究

为筛选出经济、高效、安全的化学除草方法,有效控制油菜田间杂草危害,提高油菜产量和种植效益,通过试验,研究了2种化学除草剂不同使用浓度的安全性和苗期化学除草效果,并以人工除草和不除草方法为对照,对比分析不同除草方法的投入和产出情况。结果表明：不同除草方法间油菜产量差异显著;化学除草方法对油菜田间杂草有较好的防除效果,并可显著降低油菜生产的劳动力和生产成本投入,进而提高经济效益;不同化学除草方法均于施药35天后表现出较好的除草效果;每公顷用21.2%喹·胺·草除灵悬浮剂900 mL于油菜4—5叶期、杂草3—4叶期兑水900 kg及时喷施的方法除草效果好,对油菜生长安全,可以作为冬油菜田的苗期化学除草方法在生产上应用。     

几种化学除草剂对冬油菜田的芽期除草效果研究

为筛选对油菜田芽期安全、高效、低成本的除草药剂,笔者比较了不同化学除草剂及其不同用量对防除油菜田间杂草的效果。结果表明：所用的化学除草剂对油菜无毒害作用,对油菜田的禾本科杂草和阔叶杂草的防效均在94%以上,对油菜田有增产增收的效果,增收在4340元/hm2以上,其中50%异松?乙草胺乳油1200 mL/hm2兑水1125 kg/hm2于油菜播种后进行土表喷施,除草、增产增收的效果比较好。     

直播稻田杂草发生与防除研究进展

随着水稻直播技术的推广,稻田出现杂草发生严重、除草剂用量加大等问题,而杂草发生种类、优势种群出现多样化,增加了杂草对除草剂的抗性,导致杂草防除困难,影响了直播稻的丰产与稳产;同时直播稻田除草剂的过量使用带来的生产安全性问题值得关注。本文从杂草发生种类、数量及成灾时期、发生差异性（稻作区域、种植方式、直播方式与播种期）、生态学效应及对直播稻生长发育影响等方面综述了直播稻田杂草的发生特性,分析了不同种类杂草的防除途径（化学除草、耕种制度与栽培措施）,提出我国目前在直播稻田杂草发生与防除方面研究存在的问题,并对未来直播稻田杂草防治的发展方向进行探讨与展望,旨在提高我国直播稻田杂草的防除效果,促进直播稻生产的轻简高效发展。     

灭生性除草剂草铵膦在抗除草剂转基因早稻栽培中应用效果研究

随着栽培方式的日益简化,草害成了水稻减产的重要因素,笔者以常规除草剂除草方式为对照,研究了转基因抗草铵膦杂交早稻香125S/Bar68-1在直播、抛秧和机插3种栽培方式中草铵膦的应用效果。研究结果表明：在3种栽培方式中,草铵膦除草效果都优于常规除草,尤其在杂草较多的直播田优势更加明显;虽然个别产量相关性状在不同年份存在显著差异,但草铵膦除草剂除草对转基因早稻的实际产量没有显著影响。     

Assessing non-chemical weeding strategies through mechanistic modelling of blackgrass (Alopecurus myosuroides Huds.) dynamics

Because of environmental and health safety issues, it is necessary to develop strategies that do not rely on herbicides to manage weeds. Introducing temporary grassland into annual crop rotations and mechanical weeding are the two main features that are frequently used in integrated and organic cropping systems for this purpose. To evaluate the contribution of these two factors in interaction with other cropping system components and environmental conditions, the present study updated an existing biophysical model (i.e. AlomySys) that quantifies the effects of cropping system on weed dynamics. Based on previous experiments, new sub-models were built to describe the effects on plant survival and growth reduction of mechanical weeding resulting from weed seedling uprooting and covering by soil, and those of grassland mowing resulting from tiller destruction. Additional modifications described the effect of the multi-year crop canopy of grassland on weed survival, growth, development and seed return to the soil. The improved model was used to evaluate the weed dynamics over 27 years in the conventional herbicide-based cropping system most frequently observed in farm surveys (i.e. oilseed rape/winter wheat/winter barley rotation with superficial tillage) and then to test prospective non-chemical scenarios. Preliminary simulations tested a large range of mechanical weeding and mowing strategies, varying operation frequencies, dates and, in the case of mechanical weeding, characteristics (i.e. tool, working depth, tractor speed). For mechanical weeding soon after sowing, harrowing was better than hoeing for controlling weed seed production. The later the operation, the more efficient the hoeing and the less efficient the harrowing. Tractor speed had little influence. Increasing tilling depth increased plant mortality but increased weed seed production because of additional seed germination triggering by the weeding tool. Decreasing the interrow width for hoeing was nefarious for weed control. The best combinations were triple hoeing in oilseed rape and sextuple harrowing in cereals. The best mowing strategy was mowing thrice, every 4–6 weeks, starting in mid-May. The best individual options were combined, simulated over 27 years and compared to the herbicide-based reference system. If herbicide applications were replaced solely by mechanical weeding, blackgrass infestation could not be satisfactorily controlled. If a three-year lucerne was introduced into the rotation, weed infestations were divided by ten. Replacing chisel by mouldboard ploughing before winter wheat reduced weed infestations at short, medium and long term to a level comparable to the herbicide-based reference system.     

成都平原水稻直播方式对出苗状况及产量形成的影响

为研究水稻不同直播方式在成都平原的适应性,确定最佳的直播方式,以杂交稻‘川优6203’和常规稻‘金农丝苗’为材料开展了田间试验,研究了成都平原生态条件下翻耕旱直播、免耕旱直播及翻耕水直播3种直播方式对直播稻出苗状况、生长发育、水分利用及产量形成的影响。结果表明：不同类型品种直播方式间产量的差异主要取决于有效穗数的多寡。翻耕旱直播处理前期出苗状况好、有效穗多,产量潜力最高;翻耕水直播处理前期出苗状况和产量虽不及翻耕旱直播处理,但有利于减少杂草和落田谷发生,播种后所需灌水量也最少;免耕旱直播处理存在着杂草和落田谷滋生严重、出苗差及播种后田间耗水量大等问题,产量最低。这表明翻耕条件下旱直播和水直播在成都平原各有优点,但从生产实用的角度考虑水直播更为适合。     

Effect of Sowing Date and Weed Control on Grain Yield and its Components in Some Wheat Cultivars

The influence of sowing dates (Oct. 21, Nov. 10, Nov. 30 and Dec. 21), weed control treatments using Brominal, Tribunil herbicides as compared to hand weeding and unweeded treatments on the yield performance of newly released spring wheat varieties ( Sakha 8, Sakha 61 and Giza 157 was studied during 1980/81, 1981/82 and 1982/83 seasons. According to the combined analysis the results could be summarized as follows:

• 1. 

  Sowing date had significant effect on grain yield and some other characters such as plant height, days to heading and maturity, weight of grains per spike and 1000-grain weight. Highest grain yield was obtained when wheat was sown during Nov. Dry weight of weeds was not significantly affected by sowing date.
• 2. 

  Differences between cultivars reached to the significant level in plant height, spike length, number of grains per spike and 1000-grain weight.
• 3. 

  Weed control treatments had significant effect on most studied traits. Grain yield was nearly the same when Tribunil (3.5 kg/ha), Brominal (2.4 1/ha) or hand weeding was used. Grain yield of unweed treatment decreased by 10.9%, 10.9% and 9.8% compared to the former treatments, respectively.
• 4. 

  Data showed that Tribunil was more effective on both grassy and broad leaved weeds, however, Brominal was effective only on broad leaved.

     

Development of rice (Oryza sativa) lines resistant to aryloxyphenoxypropionate herbicides through induced mutation with gamma rays

The aryloxyphenoxypropionate herbicides (APPs) are graminicides with excellent control of many grass weeds species, including weedy rice (Oryza sativa L.). These herbicides block the fatty acid biosynthesis by inhibiting the enzyme acetyl‐CoA carboxylase (ACCase), resulting in the death of susceptible plants. Inducing mutation with gamma rays to rice seeds, two lines resistant to APPs herbicides were developed. Plant dose–response assays confirmed the resistance to the APPS herbicides quizalofop‐p‐ethyl and haloxyfop‐p‐methyl. The carboxyltransferase domain fragments of ACCase from the resistant biotype and susceptible control were sequenced and compared. A point mutation was detected in the amino acid position 2,027 (Rice Genome Annotation Project: Os05g22940.1). Results indicated that resistance to APPs is a consequence of an altered ACCase enzyme that confers resistance. The use of APPs herbicide‐resistant rice lines represents an innovative and promising alternative for weedy rice control in paddy rice systems.     

蚕豆田除草剂筛选初报

采用田间试验方法,研究了3种阔叶杂草除草剂复配1种禾本科杂草除草剂对蚕豆田间杂草的防效和安全性,筛选适于内蒙古中部蚕豆田使用的除草剂。结果表明,3种防除阔叶杂草的除草剂即10%乙羧氟草醚EC、21.4%三氟羧草醚AS、48%苯达松AS与1种禾本科杂草除草剂即5%精喹禾灵EC复配,不论是常量组合处理还是倍量组合处理,对蚕豆田杂草均具有较好的防效。所有处理对杂草的鲜重防效都高于株防效;对稗草的防效相当,差异不显著;对杂草的总防效以及阔叶杂草藜和反枝苋的防效3个倍量组合处理都显著好于常量组合处理,差异达极显著水平。田间安全性调查显示,5%精喹禾灵EC 60g/hm ²+48%苯达松AS 720、1 440g/hm ²处理对蚕豆有很好的安全性,可放心使用;其次是5%精喹禾灵EC 60g/hm ²+21.4%三氟羧草醚AS 321、642g/hm ²处理,5%精喹禾灵EC 60g/hm ²+10%乙羧氟草醚EC 90、180g/hm ²处理对蚕豆安全性较差,不建议使用。     

杂草防除对双季直播优质晚籼稻产量和稻米品质的影响

为了探明杂草防除对双季直播优质晚籼稻产量形成和稻米品质的影响,以优质常规稻美香占2号（MXZ2）和优质杂交稻泰优871(TY871)为材料,设置化学除草剂除草（CW）和不除草（NW）2种处理。与NW处理相比,CW处理下MXZ2和TY871分别增产75.71%和76.00%,增产原因主要是有效穗数和穗粒数显著增加。与NW处理相比,CW处理总体能够改善直播稻的加工和外观品质,且胶稠度显著降低7.65%～8.03%。CW处理显著提高直播晚稻稻米淀粉峰值黏度、热浆黏度、崩解值和最终黏度,消减值显著下降,提升了稻米的适口性,而NW处理显著降低了MXZ2的回复值,对垩白粒率、直链淀粉和蛋白质含量无显著影响。总体来说,化学除草剂除草显著提高直播优质晚稻的产量,对直播优质晚稻的加工品质有显著改善作用,同时降低稻米垩白度和胶稠度。此外,化学除草显著影响稻米淀粉RVA谱特征值,有利于蒸煮与食味品质的改善。     

Suppressing Weeds in Direct-seeded Lowland Rice: Effects of Methods and Rates of Seeding

High weed infestation is a major constraint to widespread adoption of direct seeding of rice (Oryza sativa L.) The experiments were conducted in 1998 wet and 1999 dry seasons in the Philippines to examine the effects of seeding methods and rates on suppressing weeds in direct-seeded lowland rice. Treatments consisted of four seeding methods: conventional and modified broadcast seeding, drill seeding with east–west and north–south row orientations; three seeding rates: 40, 80 and 160 kg seed ha⁻¹ as well as two weed control levels: weed control with herbicide and no weed control. Among the seeding methods drill seeding with east–west row orientation had the lowest rice grain yield loss caused by weeds (38 % in the wet and 20 % in the dry season), whereas the highest losses because of weeds were observed with conventional broadcast seeding (59 % in the wet and 27 % in the dry season). Seeding rate was inversely correlated to weed interference. Severe rice yield reduction (71 %) caused by weeds was found at a seeding rate of 40 kg seed ha⁻¹ in the wet season. Using seeding rates of 80 and 160 kg seed ha⁻¹, respectively, lowered yield loss to 47 and 26 % in the wet season, 32 and 18 % in the dry season. Therefore suitable method and/or rate of seeding can significantly suppress weeds in direct-seeded lowland rice.     

Sunflower allelopathy for weed control in agriculture systems

Recent developments in weed science and allied aspects have involved several interdisciplinary approaches. In this context, indiscriminate use of herbicides for weed control has become a questionable subject, which besides controlling the weeds, the chemical herbicides are harmful in many ways to soil, crops, other plants and the environment as a whole. Taking into consideration ecologically sound weed management, in modern days the reliance on chemical herbicides has decreased and a shift towards naturally occurring biological herbicides has received great attention throughout the world. Sunflower is an annual dicotyledonous plant, herbaceous, erect, and a native of North America. It is thermo and photo-insensitive, hence it can be grown year round in sub-tropical and tropical countries. Only two spp. Helianthus annuus L. and Helianthus tuberosum are cultivated for food, the remaining spp., are ornamentals weeds and wild plants. However, H. annuus is allelopathic and inhibits the growth and development of other plants thus reducing their productivity. Sunflower is a major oil-yielding crop in India and its cultivation in northwest India started 25 to 30 years ago in areas located in the plains. In this region, rice-wheat rotation became very popular owing to its high yields; however, these crops are highly infested by weeds, thus farmers use herbicides for their control. Hence, this rotation consumes a maximum quantity of herbicides in this region, which has resulted in several problems viz., environmental pollution, human health hazards, and development of herbicide resistance in weeds. Thus, serious ecological questions about the reliance on herbicides for weed control in this rotation have been raised. One of the alternatives to overcome these problems is with the use of allelopathic strategies, including the use of weed-smothering crops for weed management and for the sustainability of agriculture. The field, pot culture, and laboratory studies have shown that inclusion of sunflower crops in rotation and intercropping considerably reduced the weed population in the current and succeeding crops. Rhizosphere soil of sunflower drastically smothered the weed germination, population, and biomass. The residual suppression effect of sunflower also persisted in the next crop up to 75 days. Thus, it is conceptualized that the inclusion of such oilseed crops before the rice crop in the rice-wheat rotation may provide satisfactory weed control in the succeeding rice crops and may minimize the use of herbicides. Likewise, the replacement of sorghum by summer sunflower oilseed crops may also help in the control of summer as well as winter weeds. More studies in this direction may provide avenues for satisfactory weed management in agro-ecosystems and may help to minimize the use of herbicides and thereby pave the way to develop sustainable agricultural practices for biodiversity conservation and enhancing biological integrity.     

几种除草剂对当茬玉米生长发育的影响

除草剂为作物产量提供保障的同时,对作物造成的药害也频繁发生。为此,本文以目前陇东旱塬区主栽玉米品种为试验材料,选用对恶性杂草具有良好防除效果的除草剂,明确了75%二氯吡啶酸SG、90%莠去津WG和56% 2甲4氯钠盐SP 3个单剂及其2个混配配方对玉米主要农艺性状及产量的影响,以期为玉米的安全生产提供依据。结果表明：参试除草剂在药后0~7天及不同生育期对玉米生长均无直观影响。75%二氯吡啶酸SG、90%莠去津WG、75%二氯吡啶酸SG+90%莠去津WG对苗期玉米株高稍有影响,但随着玉米自身防御能力的增强,除草剂对之后各生育期的玉米株高无显著抑制作用。不同除草剂对各生育期玉米茎粗无抑制作用,玉米果穗粗、果穗有效长、穗粒数和百粒重无显著差异。各除草剂处理后玉米产量较空白对照增加21.93%~30.22%,较人工除草对照增加-2.91%~3.69%。可见,供试除草剂对玉米安全性高,可应用于玉米田的杂草防除。     

水稻有机栽培旱育秧田除草技术研究

研究旨在从生态学角度出发,利用杂草和水稻生物学差异,探索水稻有机栽培条件下旱育秧田经济有效的除草方法。以日本优质水稻品种‘越光’(Koshihikari)为试验材料,2012年进行田间试验,随机区组设计,3次重复;2013年进行生产对比试验。2012年试验结果：比CK相对除草率依次为T4 (93.6%)＞T2(89.6%)＞T1(87.0%)＞T3(21.1%),比CK增产幅度依次为T4(11.0%)＞T2(10.0%)＞T1(7.6%)＞T3(1.0%),比CK增加收益依次为T2(4485.0元/hm²)＞T4(4218.0元/hm²)＞T1(3534.0元/hm²)＞T3(330.0元/hm²)。2013年生产对比试验结果为,T2比CK相对除草率为88.7%、比CK增产幅度为7.9%、比CK增加收益为2562.0元/hm²。2年试验结果证明,T2的除草和增产效果显著,相对收益最高。因此,播前不需引草锄灭,直接采用干种子播种和播后适时退土,即“干种+退土”是水稻有机栽培旱育秧田节本、增产、增效的除草方法。     

不同化除处理对免耕山地油菜杂草防效及其产量的影响

【目的】为有效筛选并推荐丰产性、稳定性和经济性好的免耕山地油菜化学除草技术在低纬高原山区推广应用,【方法】采用灰色关联度和模糊聚类等分析方法,对玉溪市2013-2015三年4个不同海拔试点的9种化除处理进行杂草防效、丰产性、稳定性和经济性对比分析。【结果】结果表明：(1)免耕山地油菜杂草涉及3纲12目11科25属26种,其中以胜红蓟、辣子草、尼泊尔蓼和马唐4种居多,分别占杂草总数的43.80%、34.04%、10.40%和4.41%；(2)不同化学除草处理油菜主要农艺因子与产量的关联度有明显差异,其中,油菜单株有效角果数与产量关联度最大；(3)不同化学除草处理之间的防效有不同程度的差异,其中,药后30天防效在80%以上的有3个处理,其杂草防效分别为89.8%、89.6%和85.6%；(4)不同化学除草处理之间的油菜产量都有不同程度的差异,尤其产量居前2位的2个处理与对照清水、丙酯草醚、精奎禾灵、禾耐斯4个处理之间产量达极显著差异,两处理分别比对照增产52.25%和50.04%；(5)草甘膦+禾耐斯、草甘膦+禾耐斯+丙酯草醚+精奎禾灵2个处理在4个试点的丰产性和稳定性综合评价均为很好,但前者比后者节省成本1065.0元/hm²。【结论】推荐低纬高原山区免耕油菜采用分段化学除草方法,即油菜播种前10-15天用41%草甘膦异丙胺盐AS4.5kg/hm²+油菜播后芽前用90%禾耐斯EC600ml/hm²对水600kg均匀喷施墒面和沟。     

Response of Corn Hybrids Differing in Canopy Architecture to Chemical and Mechanical (Rotary Hoeing) Weed Control: Morphology and Yield

Weed interference with the growth and yield of corn plants is affected by both mechanical and chemical means of weed control. Recently, corn hybrids accumulating more leaf area, maturing earlier, yielding better in narrower row spacings and tolerating higher plant populations better than conventional hybrids have been developed. Because of more rapid leaf area accumulation during the earliest stages of canopy development and overall canopy architecture, they may be more susceptible to damage due to mechanical weed control. The objective of this study was to assess the response of corn hybrids with a wide range of canopy architectures to chemical and mechanical (rotary hoeing) weed control, with an emphasis on quantifying morphology and grain yield responses. Field experiments were conducted in 1997 and 1998 at Ste. Anne de Bellevue, Quebec. Three hybrids were tested: leafy reduced-stature (LRS1 and LRS2), and the conventional hybrid Pioneer 3979 (P3979). Rotary hoeing alone had very little effect, while herbicide application reduced the interference of weeds with growth and grain yield of all hybrids. Hybrid P3979 had more total leaf area than LRS1 and LRS2, but the percentage of leaf area above the ear was much higher for LRS hybrids (70 %) than for P3979 (51 %). Generally, LRS hybrids were much shorter with more leaf area above the ear than P3979, contributing to the large differences in canopy architecture between the LRS hybrids and P3979. However, morphology and grain yield response of hybrids to rotary hoeing and herbicide weed control was not different, indicating that the new hybrids were not more susceptible to damage caused by mechanical weed control than a corn hybrid with a conventional canopy architecture.