豆田苍耳的生长为害习性及其防除的初步研究

本文通过小区试验及大田调查,研究了豆田恶性杂草——苍耳的生长,为害习性及竞争,明确了苍耳有生长速度快,蔓延迅速,竞争力强,对大豆生长发育影响大,在低密度条件下亦能造成严重减产特点。 化学除草剂排草丹(苯达松)、虎威、杀草丹、赛克津等均能有效地防治苍耳的为害。在大豆播后苗前,每亩用赛克津35 g(有效剂量,下同)。土壤处理;在苍耳2—5叶期,每亩用排草丹37.5 g,或虎威33.3 g,或杀草丹200g茎叶处理,均可达到95％以上的防效。排草丹、虎威等与稳杀得、盖草能或拿捕净等除草剂混用,还可兼治一年生和多年生禾本科杂草。     

除草剂、杀菌剂的选择及药害的补救

１除草剂的选择近十年来，黑龙江省农垦总局植保站组织农药联网试验，对除草剂安全性进行系统评价，结论是水稻除草剂安全性直接影响水稻产量和品质。防除稗草最安全的是禾大壮、千金，其次是杀草丹、拜田净、瑞飞特、阿罗津、苯噻草胺、农思它、快杀稗，最差的是丁草胺。防阔叶杂草的除草剂最安全的是草克星（草灭草、草威、吡嘧磺隆）、农得时、威农、金秋、太阳星、排草丹，最差的是２甲４氯及２甲４氯的混剂。应注意９０％杀草丹乳油适用于南方、北方旱育苗床封闭除草用５０％杀草丹乳油安全有效。垦区属寒温带大陆性气候，其中五至六月…     

日本政府修改和新制定的茶叶中部分农药残留标准

本刊讯今年5月28日,日本政府颁布了厚生省药品食品卫生审议会制定和修改的农药残留标准,其中与茶叶相关的有如下内容。1.新制定的农药残留标准有11种,与茶叶有关的两项为:(1)氟啶胺:茶叶(红茶、绿茶、乌龙茶)中MRL标准为5mgkg。(2)抑芽丹:茶叶(红茶、绿茶、乌龙茶)中MRL标准为0.2mgkg。2.修改的农药残留标准有4种,与茶叶有关的1项为:毒死蜱:原标准3mgkg,现放宽为10mgkg。日本政府修改和新制定的茶叶中部分农药残留标准@陈宗懋     

菜田化学除草

1白菜、甘蓝：结合整地每亩用48％氟乐灵150－200s兑水75—100kg均匀喷洒干上表，之后及时翻地（4－scm）、定植或播种。也可在菜苗移栽活棵后，亩用25％除草醚可湿性粉剂500——750R兑水砌一100kg，均匀喷洒。2芹菜、香菜、胡萝卜：在播后苗前亩用40％除草醚600－6509，或50％排草净100－130g，或40％除草醚3009加50％排草净659混合，兑水75－100kg进行土壤喷雾。也可在播前结合整地亩用48％氟乐灵150－2009，兑水75—100kg土壤喷雾，并及时没耙4—scm，之后即可播种，催芽种子则应提前一周施药。3＄子、辣椒、著茹：应用氟乐灵施药一次可…     

乙氧氟草醚在水稻及其生态环境中的残留降解动态

乙氧氟草醚在水稻及其生态环境中的残留降解动态楼小华，梁天锡，吴园生，平霄飞（中国水稻研究所杭州３１０００６）关键词乙氧氟草醚，残留降解，最终残留ＤｅｇｒａｄａｔｉｏｎＤｙｎａｍｉｃｓｏｆＯｘｙｆｌｕｏｒｆｅｎｉｎＲｉｃｅａｎｄＩｔｓＥｃｏｓｙｓｔｅｍ...     

灵斯科·丹防治稻田阔叶杂草示范试验

灵斯科·丹是一种新型低毒、低残留的除草剂。为明确灵斯科·丹对水稻田难防阔叶杂草的防治效果和对水稻的安全性,利用3%氯氟吡啶酯(EC)防治稻田阔叶杂草,当地常规药剂48%苯达松(AS)作为对照进行试验。结果表明:灵斯科·丹除草剂用量40 g/667 m^2茎叶正常雾滴喷雾较其他处理防效高、见效快、持效期长;正常雾滴喷雾产量最高,为693.7 kg/667 m^2,比空白对照增产20.9%。灵斯科·丹用量40 g/667 m^2茎叶正常雾滴喷雾具有除草速效性、彻底性,持效期长,对水稻生产安全,可以在生产上推广使用。     

乙氧氟草醚在花生上的残留动态研究

乙氧氟草醚在花生上的残留动态研究／陆贻通（浙江省农业厅环保站），徐进…环境污染与防治．－１９９４，１６（１）．－７～８为防止新除草剂乙氧氟草醚对农业生态环境污染，作者进行了该农药在花生上残留动态试验研究。残留动态试验：设２个用药剂量，每亩分别用２３．...     

省作物学会组织专家考察吉首酒用高粱生产基地

1992年8月8日至11日,省作物学会组织有关专家17人,对我省在吉首建立的第一个酒用高粱生产基地进行了现场考察。 今年,省、湘西自治州和吉首市农业部门在吉首市丹青、排绸、排吼、马颈坳等乡镇建立了1.96万亩的酒用优质糯高粱生产基地。据实地抽样考察,一般亩产300kg以上,高产丘块可达500多kg,亩产值210元以上,每个工值10元以上。当地干群反映,第一次在山坡地上种高粱,能获得如此好的收成,比种玉米产量还高,明年将进一步扩种。     

玉米杂交种及亲本对除莠剂的敏感性

按技术规程种植玉米时采用基本除莠剂——丹烯混剂,该除莠剂的有效成份是丙草丹。众所周知,它对个别玉米类型是有毒害的。按新妓术规程生产的丹烯混剂,在丙草丹药剂中混有抗毒剂——解毒剂 R25788。这种解毒剂能防止大多数玉米类型受损害,同时不降低药剂的除草作用。在此,我们首先说明已确认的杂交种对除莠剂的抗性。在试验中,研究了在乌克兰北部草原推广的某些玉米杂交种及其亲本对丹烯混剂的敏感     

2002年东北地区玉米丝黑穗病发生情况初报

2002年9月中旬，对东北三省玉米丝黑穗病进行了实地调查，结果发现，黑龙江省发生玉米丝黑穗病面积约44万hm^2，主要感病品种有白单31号、龙单19号，平均发病率分别为70％、57％；吉林省发生玉米丝黑穗病面积约60万hm^2，主要感病品种有吉单209、掖单44、登海1号、东单60、丹638、丹639等，其中一些品种平均发病率达50％以上，个别地块高达90％；辽宁省发生玉米丝黑穗病面积约3．3万hm^2，主要感病品种有沈单16号、丹638、丹639、丹3040等，沈单16号在本溪市卧龙镇平均发病率达57％。东北三省玉米丝黑穗病发生面积累计107万hm^2，以产量7500kg／hm^2计算，直接损失玉米1．2亿kg，农民减少收入9600万元(按玉米收购价0．80元／kg计算)。     

水稻苯达松敏感突变研究进展

采用γ-射线辐射诱变技术,日本和中国学者分别从粳稻和籼稻中获得了苯达松敏感致死突变体农林8号m和M8077S。水稻苯达松敏感突变也表现对磺酰脲类除草剂敏感,但对供试的其他除草剂没有差异反应。遗传分析表明,这两个突变体表现为等位的隐性单基因突变,对这两种除草剂的敏感是同一个基因突变的效应。对M8077S的突变位点进行了精细定位、基因克隆和互补试验,证明农林8号m和M8077S都是源于第3染色体上的一个细胞色素P450基因(CYP81A6)的单碱基缺失导致的移码突变:农林8号m中的CYP81A6自转录起始密码子ATG起第507位缺失了一个C,而M8077S中的CYP81A6第2058位缺失了一个G。水稻苯达松敏感突变用于两系法杂交水稻的除杂保纯,已经成功选育出3个具有苯达松敏感突变标记的光温敏雄性不育系(M8064S、苯88S、苯63S)以及相配套的3个杂交组合(丰两优2号、苯两优9号和苯两优639),分别通过了湖北和江西省品种审定;用于杂交水稻混植法制种,已经成功选育出具有苯达松敏感标记的恢复系(MC526)以及相配套的杂交组合(混制1号),制定了机械化混播制种的生产规程和技术要点。还展望了CYP81A6基因在抗除草剂育种、转基因水稻安全控制以及水稻化学杀雄方面的应用前景。     

一种不育系解决机械化制种和不育系混杂的设想与实践

劳动力成本的不断提高,劳动者减轻劳动强度的愿望日趋强烈,迫切要求杂交水稻制种过程的机械化.在制种过程中水稻光温敏核不育系遇到低温、某些细胞质雄性不育系遇到异常高温均会产生自交结实,导致杂种F1代中不育系混杂,从而降低杂交种的纯度、影响大田产量.培育对一种除草剂具有抗性、同时对另外一种除草剂敏感的水稻不育系,即抗/感除草剂水稻不育系,可以一次性解决杂交水稻机械化制种和不育系混杂两个问题.苯达松是一种对水稻安全的除草剂,但苯达松敏感隐性突变体对苯达松敏感.草铵膦、草甘膦、咪唑乙烟酸等能杀死水稻,但对具有抗性基因的水稻安全.利用苯达松敏感核不育系185BS、926BS与抗草铵膦的水稻杂交,选育出了抗草铵膦/感苯达松的水稻光温敏核不育系09F316BS、09F317BS、09F319BS和09F320BS.利用苯达松敏感核不育系185BS为受体进行遗传转化,获得了抗草铵膦和草甘膦/感苯达松的水稻光温敏核不育系EB185BS.由于这些不育系具有抗除草剂的特点,而恢复系不具备,制种时不育系与恢复系可以混播,待授粉完成后喷施除草剂杀死恢复系,成熟后机械化收割不育系上所结杂交种子,而不需要提前人工割刈恢复系;而且恢复系在不育系中均匀分布也可以提高异交率.如果在制种过程中遇到异常低气温,造成不育系少量自交结实而混杂在杂种F1代中,可以通过在杂种F1代秧田喷施苯达松杀死混杂的苯达松敏感不育系,杂交种由于野生基因的显性作用而不受伤害,从而可以保证大田F1代的纯度;此外,秧苗期喷施除草剂可以代替田间种植鉴定杂交种纯度,减少了种植鉴定中的土地占用和人工费用.本设想也可以运用到其它作物,通过培育一种抗/感除草剂的不育系来一次性解决机械化制种和清除不育系混杂的问题.     

Growth, yield and water productivity of zero till wheat as affected by rice straw mulch and irrigation schedule

Intensive cultivation of rice and wheat in north-west India has resulted in air pollution from rice straw burning, soil degradation and declining groundwater resources. The retention of rice residues as a surface mulch could be beneficial for moisture conservation and yield, and for hence water productivity, in addition to reducing air pollution and loss of soil organic matter. Two field experiments were conducted in Punjab, India, to study the effects of rice straw mulch and irrigation scheduling on wheat growth, yield, water use and water productivity during 2006-2008. Mulching increased soil water content and this led to significant improvement in crop growth and yield determining attributes where water was limiting, but this only resulted in significant grain yield increase in two instances. There was no effect of irrigation treatment in the first year because of well-distributed rains. In the second year, yield decreased with decrease and delay in the number of irrigations between crown root initiation and grain filling. With soil matric potential (SMP)-based irrigation scheduling, the irrigation amount was reduced by 75 mm each year with mulch in comparison with no mulch, while maintaining grain yield. Total crop water use (ET) was not significantly affected by mulch in either year, but was significantly affected by irrigation treatment in the second year. Mulch had a positive or neutral effect on grain water productivity with respect to ET (WP_ET) and irrigation (WP_I). Maximum WP_I occurred in the treatment which received the least irrigation, but this was also the lowest yielding treatment. The current irrigation scheduling guidelines based on cumulative pan evaporation (CPE) resulted in sub-optimal irrigation (loss of yield) in one of the two years, and higher irrigation input and lower WP_I of the mulched treatment in comparison with SMP-based irrigation scheduling. The results from this and other studies suggest that farmers in Punjab greatly over-irrigate wheat. Further field and modelling studies are needed to extrapolate the findings to a wider range of seasonal and site conditions, and to develop simple tools and guidelines to assist farmers to better schedule irrigation to wheat.     

Wheat Straw Burial Improves Physiological Traits,Yield and Grain Quality of Rice by Regulating Antioxidant System and Nitrogen Assimilation Enzymes under Alternate Wetting and Drying Irrigation

Wheat straw burial has great potential to sustain rice production under alternate wetting and drying (AWD) irrigation. A field experiment was conducted with three wheat straw burial treatments, including without straw burial (NSB), with light straw burial of 300 kg/hm² (LSB) and dense straw burial of 800 kg/hm² (DSB), as well as three AWD regimes: alternate wetting/moderate drying (AWMD), alternate wetting/severe drying (AWSD) and alternate wetting/critical drying (AWCD). The rice growth and grain quality were higher in LSB and NSB than those in NSB under the same AWD regime. The AWMD × DSB treatment resulted in the highest yield, brown rice rate, milled rice rate, amylose content and protein content. Conversely, the AWCD × NSB treatment led to the lowest yield, brown rice rate, milled rice rate, amylose content and protein content. The active absorption area and nitrate reductase activity of roots were higher in the AWMD × DSB treatment than those in the AWCD × NSB treatment, as the former increased organic carbon and nitrogen contents in the rhizosphere, whereas the latter reduced their availability. Total soluble protein content and glutamine synthetase activity were greater in the AWMD × DSB treatment than those in the AWCD × NSB treatment. The activities of superoxide dismutase and catalase were higher in the AWMD × DSB treatment compared with the AWCD × NSB treatment, leading to the amelioration of oxidative cell injury, as shown by a lower malonaldehyde level. This study suggested that farmers should implement AWMD irrigation after leaving the straw residues in the field, followed by deep tillage to improve soil quality and mitigate the drought stress cycles of AWD. This approach can improve rice growth and grain quality and alleviate the problems of disposal of straw residues and water scarcity for sustainable rice production.     

结实期土壤水分和氮素营养对水稻产量与品质的交互影响

杂交籼稻汕优63和粳稻武育粳3号种植于土培池,于始穗期进行0N（0 g/m2）、NN（中氮,4.5 g/m2 ）和HN（高氮,9.0 g/m2）3种施氮量处理,于抽穗后7 d至成熟期设置了WW（保持浅水层）、MD（轻度落干,土壤水势保持-25 kPa）和SD（重度落干,土壤水势保持-50 kPa）3种土壤水分处理,研究了结实期土壤水分和氮素营养对水稻产量与品质的交互影响。在各施氮水平下,产量、糙米率、精米率和整精米率均以MD处理最高,垩白粒率和垩白度均以MD处理最低。在0N下,SD处理降低了产量、碾磨品质、外观品质和食味品质;在MN或HN下,SD处理的产量、碾磨品质、外观品质和食味品质与WW的差异不显著或显著优于WW。说明土壤水分和氮素营养对水稻产量和品质的影响存在着明显的互作效应,结实期土壤水势为-25 kPa、粒肥的施氮量为45 kg/hm2,稻米的品质较优、产量最高。     

Effects and fate of biochar from rice residues in rice-based systems

Although crop residues constitute an enormous resource, actual residue management practices in rice-based systems have various negative side effects and contribute to global warming. The concept of a combined bioenergy/biochar system could tackle these problems in a new way. Rice residues would be used for energy production, thereby reducing field burning and the use of fossil fuels, and the biochar by-product could help to improve soils, avoid methane emissions, and sequester carbon in soils. To examine some of these promises, we conducted field experiments from 2005 to 2008 in three different rice production systems. Objectives were to study the effect of biochar from rice husks on soil characteristics, assess the stability of carbonized rice residues in these different systems, and evaluate the agronomic effect of biochar applications. The results showed that application of untreated and carbonized rice husks (RH and CRH) increased total organic carbon, total soil N, the C/N ratio, and available P and K. Not significant or small effects were observed for soil reaction, exchangeable Ca, Mg, Na, and the CEC. On a fertile soil, the high C/N ratio of CRH seemed to have limited N availability, thereby slightly reducing grain yields in the first three seasons after application. On a poor soil, where the crop also suffered from water stress, soil chemical and physical improvements increased yields by 16-35%. Together with a parallel study including methane and CO₂ emission measurements at one site, the results strongly suggest that CRH is very stable in various rice soils and systems, possibly for thousands of years. However, the study also showed that CRH was very mobile in some soils. Especially in poor sandy soil, about half of the applied carbon seemed to have moved below 0.30 m in the soil profile within 4 years after application. We concluded that biochar from rice residues can be beneficial in rice-based systems but that actual effects on soil fertility, grain yield, and soil organic carbon will depend on site-specific conditions. Long-term studies on biochar in field trials seem essential to better understand biochar effects and to investigate its behavior in soils.     

Variation in rice quality of different cultivars and grain positions as affected by water management

A field experiment was conducted to study the effect of cultivar and grain position on rice quality under different water management treatments. Water treatments significantly affected all quality traits in the study, except alkali digestibility (AD). There were significant interactions of water treatment by grain position and genotype for brown rice rate (BRR), chalky grain rate (CGR) and amylose content (AC), and interactions of grain position by water treatment and cultivar for head milled rice rate (HMRR). The interaction of water treatment by genotype for protein content (PC) was also significant. Of all variance components, water treatment ranked the highest for PC. Similarly grain position was ranked the highest for AC, BRR, CGR and HMRR. In comparison with wet cultivation, plastic-film mulched cultivation had significantly lower BRR, HMRR, CGR and higher PC. There were marked differences in milled quality, appearance and AD among differently positioned grains within a spike. For appearance and PC, the difference between plastic-film mulched cultivation and wet cultivation was greater for upland rice than paddy rice. For milled and cooking–eating quality, the difference between plastic-film mulched cultivation and wet cultivation was greater for the good quality paddy rice than the upland rice and the poor quality paddy rice. In plastic-film mulched cultivation, top grains showed lower milled quality and PC. While in wet cultivation, the opposite result was seen. With the decrease in soil water content, BRR and appearance showed increased and decreased differences among grains within a spike, respectively. The results indicate the possibility of improving rice quality by use of better water management and suitable cultivars.     

SCAR 标记对水稻苯达松敏感致死基因的辅助选育

 利用与苯达松敏感致死基因（ben）紧密连锁的SCAR标记，对田间以农林8号m为ben基因供体转育的后代进行了PCR检测。利用该标记不仅能鉴别出转育的材料是否含有ben基因，而且能区别它是含ben基因的纯合体还是杂合体，从而有效地指导田间选育，加速育种进程。     

SCAR Markers Assisted Selection for a Bentazon Susceptible Lethality Gene (ben) in Rice

In progenies resulting from crosses involving rice cultivar Norin 8m susceptible to bentazon as the donor of ben gene, SCARs tightly linked to ben were utilized for selection of ben. The homozygous and heterozygous genotypes with ben could be identified with the SCARs. The molecular markers offer a powerful tool for indirect selection of ben and can accelerate the introgression of ben into current rice cultivars.