青海省春麦田杂草种类组成及群落特征

对青海省春小麦田杂草发生种类、群落构成及发生规律进行了调查研究。结果表明:青海省春麦田杂草共有87种,隶属于25科。其中单子叶植物1科8种,双子叶植物24科79种。猪殃殃、藜、荞麦蔓、密花香薷、节裂角茴香、萹蓄等6种杂草为田间的优势杂草;尼泊尔蓼、西伯利亚蓼、野燕麦、芦苇、繁缕、苣荬菜、大刺儿菜为田间区域性优势杂草。发生规律的研究表明青海川水地区春麦田杂草出苗高峰期在5月中、下旬;脑山地区春麦田杂草出苗高峰期在5月上、中旬,1~2cm土层是杂草出苗的最适深度。青海春麦田杂草由过去的野燕麦和一年生双子叶杂草为主的群落结构明显向以多年生杂草和部分耐药性强的一年生杂草为主的群落结构演替。     

豫北露地直播棉田杂草的发生及其与棉花的竞争作用

 为了明确棉田自然混生杂草对棉花的危害程度及其关键防除时期,通过田间杂草共生期试验,研究了豫北露地直播棉田杂草的发生及其与棉花的竞争临界期。结果表明,豫北地区露地直播棉田的优势杂草为牛筋草、马齿苋、藜和鳢肠,杂草出土高峰期集中在棉花苗期和花蕾期,且存在3个出土高峰,分别在5月中旬、6月上中旬和7月中下旬。当杂草与棉花竞争持续时间少于4周时,由于杂草与棉花植株均较小,且土壤中养分相对充足,因此杂草对棉花生长和产量的影响不大;当杂草与棉花竞争期达8周以上时,杂草对棉花的竞争作用明显增强,棉花的株数减少,茎秆变细,形成瘦高植株,且单株结铃数、铃重等产量指标明显降低。因此,豫北棉田自然混生杂草群落与棉花的竞争临界期为棉花出苗后4～8周,在此期间应采取相应措施,保证田间无草害。     

不同药剂防除花生田阔叶草效果研究

为评价50%丙炔氟草胺可湿性粉剂(锄青)在花生田的安全性及对阔叶杂草的防除效果,用对比试验法研究了多种药剂对花生田阔叶草的防除效果。结果显示,50%丙炔氟草胺可湿性粉剂(锄青)对花生出苗无影响,苗后到收获期花生长势良好,无药害症状,对马齿苋、反枝苋、藜和铁苋菜防治效果较好,明显高于其他药剂,持效期长达60 d。     

黑龙江省六个地点鸭跖草RAPD遗传多样性分析

利用随机扩增多态性DNA(RAPD)技术对采自黑龙江省五大连池、铁力、通北、八五四农场、红旗岭农场和佳木斯等6个地点45份鸭跖草的遗传多样性进行分析.在筛选的150个RAPD引物中,有60个RAPD引物的扩增带型清晰且重复性好,共检测出349个位点,多态性位点127个,多态性占总位点数的36.4%.45份鸭跖草的遗传相似系数范围为0.556～0.979,以相似系数0.77为界聚为四类,利用STRUCTURE分析验证了这一分类结果.不同地点鸭跖草的遗传多样性及其地区专化性,为鸭跖草的防除提供了理论依据.     

盐碱土上3种植物出苗研究

通过在育苗盘上进行种子出苗试验,研究了不同草种（披碱草、草木樨和紫花苜蓿）、不同土壤（pH 10.03、9.36、8.68、8.12,电导率(EC)为2.02、1.237、0.962、0.454 mS/cm）、不同播深(1、3 cm)和不同种子播种前处理（晒种浸泡处理和未处理）对出苗时间和出苗率的影响。结果表明：披碱草耐盐碱性最好,草木樨最差;超过一定限度(pH＞8.68,EC＞0.962 mS/cm),pH或电导率增加,均会造成出苗时间增长,出苗率下降;播深1 cm比3 cm出苗时间显著缩短,出苗率显著提高;种子晒种浸泡处理可以显著缩短出苗时间,提高出苗率,对种子出苗有一定帮助。试验同时表明,在盐碱土上缩短出苗时间,对提高出苗率有利。     

昆明菜区甜菜夜蛾和斜纹夜蛾发生规律

2016—2019年采用性信息素诱捕器监测昆明菜区甜菜夜蛾和斜纹夜蛾种群。结果表明,甜菜夜蛾和斜纹夜蛾全年都发生危害,全年发生1~2个高峰期,斜纹夜蛾诱集虫量是甜菜夜蛾虫量的7.09~14.89倍。2016—2017年甜菜夜蛾发生高峰期都在5月下旬—10月中下旬;2018年发生高峰期在5月10日—7月31日和8月31日—9月10日;2019年全年虫量最少,发生高峰期在4月下旬—9月下旬。2016年斜纹夜蛾发生高峰期在5月下旬—10月上旬;2017年发生高峰期在6月30日—8月31日和9月30日—11月30日;2018年发生高峰期在5月10日—7月31日、11月;2019年发生高峰期在4月30日—9月30日、11月。甜菜夜蛾和斜纹夜蛾发生高峰期在夏秋季,本研究可为昆明菜区甜菜夜蛾和斜纹夜蛾绿色防控提供数据参考。     

防除大豆田杂草良药氯酯磺草胺

<正>氯酯磺草胺(豆杰)是美国陶氏益农公司最新研制的磺酰胺类除草剂,主要用于大豆田茎叶喷雾防除阔叶杂草。药剂经杂草叶片、根吸收累积在生长点,抑制乙酰乳酸合成酶(ALS),影响蛋白质的合成,使杂草停止生长而死亡。田间药效试验表明,氯酯磺草胺对春大豆田阔叶杂草鸭跖草、红蓼、豚草有较好的防除效果,对苦菜、苣荬菜有较强的抑制作用。     

辣椒“鸡爪疯”真凶——茶黄螨的防治

<正>近年来辣椒"鸡爪疯"发生率越来越高,一般开始于5月中下旬,到6月中下旬,大面积辣椒叶片卷曲,尤以嫩叶最为严重,最终脱落掉光。辣椒植株的分枝生长顶端由于叶片脱     

适于大豆田苗后防除阔叶草除草剂有哪些?

<正>1.氟磺胺草醚商品名:虎威、福草灵、帅虎、豆来福,主要剂型:16.8%、25%水剂,10%、12.8%、20%乳油。属二苯醚类选择性触杀型除草剂,杂草茎叶及根均可吸收,杂草受害症状为叶片黄化或有枯斑,最后枯萎死亡。氟磺胺草醚主要防除苋、蓼、藜、龙葵、狼巴草、鸭跖草、香薷、小蓟、大蓟、苣荬菜、问荆等。25%氟磺胺草醚水剂在阔叶杂草2⁴叶期每亩用药674叶期每亩用药67¹00毫升,加333克尿素能提高除草效果。使用氟磺胺草醚应掌握好用药时期。施药过早杂草出苗不齐,对还没出土的杂草起不到杀草作用;施药过晚,杂草抗药性增强,会降低除草效果。一般应在多数杂草2100毫升,加333克尿素能提高除草效果。使用氟磺胺草醚应掌握好用药时期。施药过早杂草出苗不齐,对还没出土的杂草起不到杀草作用;施药过晚,杂草抗药性增强,会降低除草效果。一般应在多数杂草2⁴叶期并且     

及早防除萝卜杂草

<正>萝卜出苗后前期生长慢,苗体小,易受杂草为害。特别是在秋雨频繁天气,杂草出苗量和生长量大,会使萝卜生长发育受到严重抑制,应及早防除。萝卜播后苗前,可每亩用25%利谷隆可湿性粉剂250～400克,或48%氟乐灵乳油100～150毫升,或50%杀草丹乳油300～400毫升,     

Soil Temperature and Planting Depth Effects on Tef Emergence

Tef [ Eragrostis tef (Zucc.) Trotter] is an annual C4 grass crop that originated in Ethiopia. It has potential as a grain crop in the Great Plains because of its tolerance to drought and high temperatures. In Ethiopia, tef seed is typically broadcast on the soil surface and lightly incorporated. Shallow planting depths are used because the seed is very small and emergence can be limited by soil crusting. If planting equipment is to be used, planting depth may be important for successful tef production. The objective of this study was to identify optimal depths and soil temperatures to aid in developing tef planting recommendations for the central Plains. Tef was planted at five depths (0, 0.6, 1.3, 2.5 and 5.0 cm) in pots filled with a silt loam soil, and pots were placed in growth chambers at four temperature regimes (day/night: 15/19 °C; 19/23 °C; 23/27 °C and 27/31 °C). No plants emerged from the 5.0-cm depth, so this depth was not included in the analysis. Emergence was greatest for planting depths of 0.6 and 1.3 cm and lower at 0 and 2.5 cm depths. Temperature did not affect final emergence, measured 21 days after planting (DAP), but did influence emergence rates during the first 9 DAP. Plant dry matter production increased as planting depth increased, but plant dry matter per pot was not different among planting depths greater than 0.9 cm, suggesting that compensation between plants across different plant densities began early in the plants' life cycles. Our results show that tef seed can emerge from depths between 0.6 and 1.3 cm and that soil temperatures below 19 °C can slow emergence but should not affect final stands.     

起垄覆膜与土壤脱盐剂对江苏沿海中重度盐碱地棉花成苗和产量的影响

以中棉所79为材料,于2012和2013年在江苏大丰稻麦原种场盐碱地设计高垄覆膜、高垄不覆膜、土壤脱盐剂+覆膜、土壤脱盐剂+高垄覆膜、土壤脱盐剂+高垄不覆膜和平作覆膜6个处理对棉花出苗、产量及与抗盐相关的生理指标影响。结果表明:与平作覆膜相比(CK),高垄覆膜+土壤脱盐剂能显著提高籽棉产量和促进出苗,产量比对照提高32.00%~113.78%;土表20 cm土壤盐分降低最多,下降42.07%,出苗率提高148.8%。同时高垄覆膜+土壤脱盐剂处理能有效地减少棉苗叶片丙二醛和脯氨酸的积累,降低叶片超氧化物歧化酶(SOD)活力。因此,高垄覆膜与土壤脱盐剂的应用,由于能有效降低中重度盐碱地的盐分,从而有利于棉花发芽出苗,降低盐分逆境对棉苗的胁迫效应,最终促进产量提高。     

Studies on Sowing Depth for Chickpea (Cicer arietinum L.), Faba Bean(Vicia faba L.) and Lentil (Lens culinaris Medik) in a Mediterranean-type Environment of South-western Australia

Pulses such as chickpea, faba bean and lentil have hypogeal emergence and their cotyledons remain where the seed is sown, while only the shoot emerges from the soil surface. The effect of three sowing depths (2.5, 5 and 10 cm) on the growth and yield of these pulses was studied at three locations across three seasons in the cropping regions of south-western Australia, with a Mediterranean-type environment. There was no effect of sowing depth on crop phenology, nodulation or dry matter production for any species. Mean seed yields across sites ranged from 810 to 2073 kg ha⁻¹ for chickpea, 817–3381 kg ha⁻¹ for faba bean, and 1173–2024 kg ha⁻¹ for lentil. In general, deep sowing did not reduce seed yields, and in some instances, seed yield was greater at the deeper sowings for chickpea and faba bean. We conclude that the optimum sowing depth for chickpea and faba bean is 5–8 cm, and for lentil 4–6 cm. Sowing at depth may also improve crop establishment where moisture from summer and autumn rainfall is stored in the subsoil below 5 cm, by reducing damage from herbicides applied immediately before or after sowing, and by improving the survival of Rhizobium inoculated on the seed due to more favourable soil conditions at depth.     

桉树人工林土壤种子库研究

为了了解桉树人工林土壤种子库的物种组成、密度、垂直分布等特征,以2年生桉树人工林为研究对象,相邻的大叶栎人工林作对照,取其土壤,通过室内种子萌发的方法,研究桉树人工林土壤种子库分布特征。结果表明：（1）各土壤层种子萌发的规律基本一致,大约从第7天开始进入种子萌发高峰期,第19天萌发高峰期基本结束,随后进入缓慢萌发期,至最后停止萌发;（2）桉树人工林土壤种子库储量较大,种子密度为9804粒/m2（对照为3614粒/m2）,共计物种15种,分属于9科,其中禾本科的弓果黍为优势种,种子密度为8849粒/m2,占土壤种子库总量90.26%;（3）种子库垂直分布格局显示,80%以上的种子储存在枯枝落叶层和0~5 cm的土壤中。2年生桉树人工林土壤种子库的种子密度大于大叶栎人工林,其组成以草本为主,灌木次之,种子多集中在枯枝落叶层和浅层土壤中。     

光照和沙埋对沙生针茅种子萌发与幼苗出土的影响

为了对沙生针茅种子萌发特征和休眠机理的研究,采用种子萌发学和实验生态学方法,研究了不同光照、划破种（果）皮及切除不同比例胚乳对种子萌发的影响和模拟野外条件对不同沙埋深度幼苗出土的影响。结果表明：黑暗条件下种子萌发率显著高于光条件下;移走胚乳75%时,种子萌发最快;不同沙埋深度以0.5 cm的浅层沙埋时的种子萌发率和幼苗出土率最高而休眠率最低;沙埋超过2 cm后,种子萌发率、幼苗出土率与沙埋深度呈负相关,休眠率随着沙埋深度的增加而增加。说明沙生针茅种子为休眠型暗条件萌发类型。人工播种应以0.5~2 cm深度为宜。     

The effect of wheat straw residue on the emergence and early growth of sugar beet (Beta vulgaris) and oilseed rape (Brassica napus)

The management of straw residue can be a concern in non-inversion tillage systems where straw tends to be incorporated at shallow depths or left on the soil surface. This can lead to poor crop establishment because straw residue can impede or hinder crop emergence and growth. Small container-based experiments were undertaken using varying amounts of wheat straw residue either incorporated or placed on the soil surface. The effects on days to seedling emergence, percentage emergence, seedling dry-weight and soil temperature using sugar beet and oilseed rape were investigated because these crops often follow wheat in a cropping sequence.The position of the straw residue was found to be the primary factor in reducing crop emergence and growth. Increasing the amount of straw residue (from 3.3 t ha^?1 to 6.7 t ha^?1) did not show any consistent trends in reducing crop emergence or growth. However, in some instances, results indicated that an interaction between the position and the amount of straw residue occurred particularly when the straw and seed was placed on the soil surface. Straw placed on the soil surface significantly reduced mean day-time soil temperature by approximately 2.5 °C compared to no residue. When the seed and straw was placed on the soil surface a lack of seed-to-soil contact caused a reduction in emergence by approximately 30% because of the restriction in available moisture that limited the ability for seed imbibition. This trend was reversed when the seed was placed in the soil, but with straw residue still on the soil surface, because the surface straw was likely to reduce moisture evaporation and improved seed-to-soil contact that led to rapid emergence. In general, when straw was mixed in or placed on the soil surface along with the seed, sugar beet and oilseed rape emergence and early growth biomass was significantly restricted by approximately 50% compared to no residue.The consequences of placing seed with or near to straw residue have been shown to cause a restriction in crop establishment. In both oilseed rape and sugar beet, this could lead to a reduction in final crop densities, poor, uneven growth and potentially lower yields that could lower financial margins. Therefore, if farmers are planning to use non-inversion tillage methods for crop establishment, the management and removal of straw residue from near or above the seed is considered important for successful crop establishment.     

农业措施对小麦田主要禾本科杂草出苗的影响

为探明播种、耕作等农业措施对小麦田主要禾本科杂草出苗的影响,对西安地区小麦田主要禾本科杂草多花黑麦草、节节麦、野燕麦、日本看麦娘、假看麦娘的田间落种状态、形态特征及不同土壤深度下出苗规律进行研究。结果表明,小麦机播深度(4~5 cm)对上述5种杂草出苗均无影响;小麦撒播深度(0~1 cm)出苗时间最早,但因表层土壤湿度较差导致出苗量低;旋耕深度(10~15 cm)出苗最晚,该深度对多花黑麦草、节节麦、野燕麦的出苗量无影响,但对日本看麦娘、假看麦娘出苗影响较大,尤其对个体小、重量轻的假看麦娘影响最大;深翻深度(30~35 cm)对5种杂草种子萌发均有抑制作用。     

AlomySys: Modelling black-grass (Alopecurus myosuroides Huds.) germination and emergence,in interaction with seed characteristics,tillage and soil climate: I. Construction

Models quantifying the effects of agricultural practices on weed emergence, in interaction with the soil, are necessary to evaluate and design cropping systems. In the present study, such a model was developed for black-grass (Alopecurus myosuroides Huds.), a harmful weed frequently found in rotations consisting mostly of winter crops. The model AlomySys was based on sub-models predicting (a) soil environment (climate, structure) resulting from the cropping system and weather, (b) vertical soil seed distribution after tillage, depending on the tool, the characteristics of the tillage implement and the soil structure; and (c) seed mortality, dormancy, germination and pre-emergent growth depending on soil environment, seed depth, characteristics and past history. Seed movements during tillage depend on the tool used, its characteristics, soil structure and on the initial position of the seed. Seed mortality increases with seed age; seed dormancy depends on seed age, seed depth, the conditions in which the seeds were produced and the past moisture and dryness conditions undergone by the seeds; germination is triggered by rain or tillage and driven by hydro-thermal time; pre-emergent shoot elongation depends on seed weight, on the conditions in which the seeds were produced and increases with thermal time; pre-emergent seedling mortality increases with soil dryness, clod size and seed depth. The sub-models were based either on existing models, or developed with literature data or additional experiments. Simulations were carried out to show how weed emergence can be reduced by adapting tillage mode and date to previous crop history.     

复配种衣剂对豌豆生长及产量的影响

选用亮盾（杀菌种衣剂）、高巧（杀虫种衣剂,间接防治病毒病）和凯普克（植物生长调节剂）3种药剂进行复配,对甜豌3号、绿宝、宝峰6号和食荚大菜豌1号等4个菜豌豆品种进行种子包衣,根据出苗率、主要农艺性状和产量表现等,研究确定最佳药种比。结果表明,药种比为1∶0.5时,甜豌3号和绿宝出苗受抑制;药种比为1∶7.5时,出苗率、农艺性状和产量无显著变化;药种比为1∶5.0时出苗率最高,幼苗长势最好,平均产量比对照增加20.5%。因此,复配种衣剂处理豌豆种子的最佳配比是：亮盾10mL、高巧20mL和凯普克10mL混匀包衣5.0kg豌豆种子。