Integrated Pest management in Forage Alfalfa

Alfalfa, Medicago sativa L., is among the most prized of forages, and is grown worldwide as a feed for all classes of livestock. It is one of man's oldest crops, and its cultivation probably predates recorded history. In addition to its versatility as a feed, alfalfa is well known for its ability to improve soil structure and, as a legume, is an effective source of biological nitrogen. As a perennial crop, alfalfa has a lifespan approaching 5 years, but in some areas of the world fields may remain productive for considerably longer. Such a long stand life affords ample time for the establishment and development of a diverse community structure by an abundance of organisms. In spite of system perturbations caused by frequent harvests and occasional pesticide applications, an alfalfa field provides a temporal stability which is uncommon among field crops. As a result of this stability, alfalfa supports an immense diversity of flora and fauna which, at times, exceeds that of riparian ecosystems. While most of alfalfa's inhabitants have little or no impact on it as a crop, a few are capable of causing extensive damage. Arthropods, plant pathogens, weeds, vertebrates, and plant parasitic nematodes can all cause significant yield and/or quality reductions and frequently contribute to shortening the productive life of the stand. This paper reviews the major strategies which have been developed to manage many of these alfalfa pests including: host plant resistance; cultural controls, such as harvest strategies, irrigation management, sanitation, planting schedules, and crop rotation; mechanical and physical controls; chemical control; and biological controls. Multiple pest interactions, e.g. insect-insect; insect-disease; insect-weed, and their management are discussed. Potential conflicts arising from the use of strategies which may reduce one pest but exacerbate others are also examined. A cross index of management strategies and their role in managing multiple pests is provided. Computer models, both ecological and economic, and their role in alfalfa pest management are discussed. Selected information sources on alfalfa and alfalfa IPM available over the Internet are listed. Alfalfa's role in the agricultural landscape, as it relates to pests, natural enemies, and pest management in other cropping systems as well as its role in crop rotation, is considered.     

湘西南地区马蹄金草坪中春季杂草的化学防除试验

湘西南地区马蹄金Dichondra repens草坪化学防除春季杂草表明:0.05 g/m2 2甲4氯钠 0.045mL/m2高效盖草能能有效防除半边莲Lobelia chinensis,0.15 mL/m2猪秧净能有效防除空心莲子草Alter-nanthera philoxeroides、天胡荽Hydrocotyle sibthorpioides、香附子Cyperus rotundus、佛甲草Sedum lineare等.0.05 g/m22甲4氯钠 0.045 mL/m2高效盖草能 0.15 mL/m2猪秧净能有效防除空心莲子草、天胡荽、香附子、佛甲草、野艾蒿Artemisia lavandulaefolia、直立婆婆纳Veronica arvensis、半边莲、车前草Plan-tago asiatica,0.05 g/m22甲4氟钠 0.045 mL/m2高效盖草能 0.15 mL/m2猪秧净 0.01 mL/m2高效盖草特对马蹄金有伤害.     

山岗瘠薄地苹果增产措施探索

为探索山丘薄地苹果树的有效增产措施,1989～1993年在新密市牛店乡的花家店小流域建立了3hm~2苹果丰产试验园.经5年试验,初步探索出了一套切实可行的增产措施,明显提高了果品产量及质量,与对照区相比,1994年、1995年、1996年苹果增产幅度分别为150%、220%及212%.其主要增产措施是:以保水增肥为中心,利用秸秆、杂草进行果园常年覆盖或春夏覆盖秋后掩埋覆草,并结合山地果树生长特点进行科学修剪.     

直播早稻杂草发生规律研究

为明确直播早稻田间主要杂草群落组成及发生趋势,指导农民科学使用除草剂。采用“W”型五点取样法对象山县直播早稻田杂草群落开展调查。结果表明直播早稻田杂草共有5科14种,以千金子、稗草为主要杂草,禾本科、莎草科及阔叶杂草分别占杂草出草总量的73.2%、13.6%和13.2%。播种后3-4天禾本科杂草开始萌发,特别是稗草出草较早,播后7-14天莎草科、阔叶杂草开始萌发。播后28天,出现第一个出草高峰,杂草总量达427株/m2,主要为禾本科杂草,占总出草量的82.7%。播后42d时出现出草高峰趋势,达到364株/m2,主要是阔叶杂草和莎草科杂草大量萌发。     

116株芒果炭疽病菌对咪鲜胺的敏感性测定

研究芒果炭疽病菌对咪鲜胺的敏感性,以期为该病的综合防治提供参考。从国内及国外芒果产区采集病样,分离、纯化芒果炭疽菌菌株,采用生长速率法测定芒果炭疽病菌对咪鲜胺的敏感性。结果表明,分离获得的116株芒果炭疽病菌菌株对咪鲜胺的EC50值为0.000 8~0.073 9μg/mL,平均值为0.012 4μg/mL,EC50最大值是最小值的92.4倍。不同采集地区和采集部位菌株对咪鲜胺的敏感性不同,美国夏威夷的菌株敏感性最低,广东的最高;分离自叶片的菌株敏感性最高,果实的最低。芒果炭疽病菌对咪鲜胺具有较高的敏感性,生产上仍具有较高的使用价值,但不同菌株的敏感性之间具有一定差异性,存在潜在的抗性风险。     

新疆天然草地毒草灾害、地理分布与防控对策

新疆天然草地是少数民族地区畜牧业发展的物质基础,也是维持新疆自然生态坏境的重要组成部分。但长期以来,由于草地干旱、严重超载放牧、盲目开垦、人口增长等自然和人为因素的影响,以及草地基础设施建设投入不足和管理滞后,草地逆向演替,使得优良牧草逐年减少,毒草趁机大量繁衍滋生,造成草地大面积沙化和毒草化,致使大量家畜每年因误食毒草而中毒,甚至死亡。特别是近几十年来,草地毒草的迅速蔓延,造成草地植被群落和生物多样性减少,植被单一化,可食牧草急剧减少、草产量下降,草地退化和毒草化程度加剧。严重制约了草地畜牧业经济的持续发展,部分牧区天然草地毒草化已导致毒害草灾害多发、频发,甚至爆发,已经从基本的生态学问题上升为一个社会问题。新疆是中国主要牧区之一,天然草地总面积5 725.88万hm²,可利用草地面积4 800.68万hm²,位居全国第三。目前85.0%可利用天然草地出现不同程度的退化,37.50%草地严重退化,毒草发生面积接近700万hm²,约占全国天然草地毒草危害面积的20.42%,年平均牲畜毒草中毒死亡数超过3 000余头（只）。新疆天然草地常见有毒植物有81种分属24科54属,对草地畜牧业造成严重危害的主要有白喉乌头、准噶尔乌头、醉马芨芨草、小花棘豆、变异黄芪、无叶假木贼、马先蒿、橐吾和毒芹,约占毒草危害总面积的80%以上。因此,全面了解新疆天然草地毒草灾害状况、毒草种类与地理分布,对有效防控和化解毒草危害,提高草地生产力和牧草品质,促进牧区畜牧业的可持续发展和农牧民增收,繁荣边疆少数民族经济,维护生态环境平衡具有重要意义。本文在对已报道文献资料分析、归纳的基础上,结合课题组对新疆天然草地毒草实际调查情况,分别就近年来新疆天然草地毒草对区域草地生态及畜牧业生产造成的灾害状况、毒草种类与地理分布、毒草防控对策及合理利用进行综述。在此基础上,结合课题组多年来致力于中国西部毒草防控研究现状,分析了新疆天然草地目前存在毒草种类繁多、灾害严重、防治困难等问题及原因,提出应从生态角度出发,转变传统防除观念,科学认识毒草,立足“变害为利,变废为宝”,生态保护与开发利用并重的思路,学习借鉴美国等发达国家在有毒植物预防控制技术方面的成功经验,以生态控制为主多种手段相结合的综合防控技术预防毒草灾害发生,以期为人们充分认识毒草在天然草地中的生态作用以及有效防控毒草灾害提供基础资料。     

Quantitative reproductive potential of Heterodera schachtii on weeds typical for late summer fallow in sugar beet rotations

In Europe, sugar beet is often produced in a 3‐year rotation with cereals, leaving stubble fields fallow from cereal harvest until primary tillage in autumn in the year prior to sugar beet production. The weed flora on such fields could include host plants of Heterodera schachtii that is one of the most important pests of sugar beet. Crop sequences with non‐hosts and cover cropping with resistant cruciferous hosts during this period have been crucial for its management. Availability of resistant and tolerant sugar beet cultivars could entice growers to forego cover cropping, exacerbating weed problems during the fallow period. The objective of this study was to determine the reproductive potential of H. schachtii on weeds that develop during this period. Under glasshouse conditions, reproduction on 39 plant species was compared with that on oilseed radish and sugar beet of differing nematode host status. In 2 years in field microplots, 18 previously tested species were grown in H. schachtii‐infested soil during the typical fallow period at 60 plants m^?2, and nine of these species were also grown at 180 plants m^?2. There were variable results between years after 8 weeks of growth, but most weeds allowed lower reproduction (<10%) than the susceptible sugar beet; only Stellaria media at 180 plants m^?2 and Thlaspi arvense at both plant densities increased nematodes. Such weed densities may seldom occur under commercial conditions; thus, weed management for nematological considerations during the stubble period may have limited importance.     

Karrikins promote germination of physiologically dormant seeds of Chrysanthemoides monilifera ssp. monilifera (boneseed)

Physiological dormancy in weed species has significant implications for weed management, as viable seeds may persist in soil seedbanks for many years. The major stimulatory compound in smoke, karrikinolide (KAR₁), promotes germination in a range of physiologically dormant weed species allowing targeted eradication methods to be employed. Control of Chrysanthemoides monilifera ssp. monilifera (boneseed), a Weed of National Significance in Australia, may benefit from adopting such an approach. In this study, we hypothesised that seeds of C. monilifera ssp. monilifera exhibit physiological dormancy, germinate more rapidly as dormancy is alleviated, show fluctuations in sensitivity to KAR₁ and form a persistent soil seedbank. Seeds responded to 1 μM KAR₁ (40–60% germination) even during months (i.e. March, April, July, August) when seeds were observed to be more deeply dormant (control germination: 7–20%). Seeds germinated readily over a range of cooler temperatures (i.e. 10, 15, 20, 20/10 and 25/15°C) and were responsive to KAR₂ (~50% germination) as well. Eradication efforts for C. monilifera ssp. monilifera may benefit from use of karrikins to achieve synchronised germination from soil seedbanks, even at times of the year when C. monilifera ssp. monilifera seeds would be less likely to germinate, allowing more rapid depletion of the soil seedbank and targeted control of young plants.     

几种除草剂对冬麦田杂草的防除效果

通过田间药效试验,比较不同除草剂对当前南疆地区冬麦田播娘蒿、萹蓄、硬草等杂草的防除效果,为科学、安全、高效应用除草剂提供依据。结果表明,药后50 d,10％苯磺隆可湿性粉剂18．0 g a．i．／hm2＋5％唑啉草酯·炔草酯乳油37．5 g a．i．／hm2、75％苯磺隆水分散粒剂18．0 g a．i．／hm2＋10％乙羧氟草醚乳油12．0 g a．i．／hm2＋5％唑啉草酯·炔草酯乳油37．5 g a．i．／hm2、37％炔·苄·唑草酮可湿性粉剂166．5 g a．i．／hm2对播娘蒿的株防效、鲜质量防效均为100％,对萹蓄的鲜质量防效均在92％以上,对硬草的株防效、鲜质量防效均在88％以上,且对小麦生长安全。     

Biological control of Rumex obtusifolius and Rumex crispus by goat grazing

Rumex obtusifolius and Rumex crispus are problematic grassland weedy species, particularly under conditions of organic farming. They are avoided by cattle and horses, but they can be grazed by goats. The aim of this study was to investigate the effectiveness of continuous goat grazing of moderate intensity on R. obtusifolius and R. crispus control. In 2008, 40 seedlings of each species were transplanted into pasture that was grazed by goats (crossbreed Czech white × Czech brown) on the target sward height of 7–10 cm. The number of leaves, proportion of grazed leaves and mortality of plants were monitored over the following 4 years. The number of leaves per plant was higher for R. obtusifolius than for R. crispus. The maximal number of leaves per plant of R. obtusifolius and R. crispus was 10 and 5, respectively. The proportion of grazed leaves was generally higher for R. obtusifolius than for R. crispus and ranged from 10% to 80%. No fertile plant was recorded during the experiment, as goat grazing totally prevented the flowering of both species. The level of mortality of the plants at the start of the fourth grazing season was 70% and 87% for R. obtusifolius and R. crispus, respectively, and no plant survived the fourth grazing season. It was concluded that continuous goat grazing of a moderate intensity that is carried out over 4 years seems to be an effective method for the non‐chemical control of R. obtusifolius and R. crispus in grassland.