干旱绿洲区枣园冠层微环境调控效应

在新疆干旱绿洲区,枣树花期常遇高温干旱天气,易造成坐果率低而导致红枣产量下降,增加灌水和人工弥雾等现有微环境调控技术易出现灌溉水利用效率低,农业面源污染严重,劳动强度大等问题。将盛花期微喷弥雾技术与微灌技术一体化,在两树行中间增加弥雾,架设高度0.5 m的雾化喷头,设置了弥雾30 min(T1),60 min(T2),90 min(T3)及滴水处理(T4),以常规滴灌处理(CK)为对照,通过大田试验研究了微喷弥雾对枣园冠层微环境的调控效应。结果表明:干旱绿洲区红枣园冠层中部在盛花期时的高温天气每日会出现低温高湿和高温低湿两段共计约14 h左右的不适于红枣开花坐果的时段,微环境调控空间很大;处理T1~T4冠层中部温度较周围环境和CK分别低11.0%,10.5%,12.5%,14.0%和2.3%,0.4%,2.6%,3.8%,湿度较周围环境及CK分别高23.7%,20.0%,21.2%,17.2%和5.3%,2.2%,3.2%,-0.1%,产量较对照分别高9.4%,6.8%,6.7%,10.2%,表明微喷弥雾具有一定的改善冠层微环境和增产的作用;干旱绿洲区枣园冠层中部的空气温度与相对湿度呈较好的负线性关系;微喷弥雾对红枣树坐果率和果实品质的影响不尽相同,综合考虑产量和果实品质,微喷弥雾30 min的处理最佳,建议微喷弥雾应在12∶00和16∶00分两个时段进行。     

脱落酸功能类似物萘酮戊酸对葡萄着色与品质提升的影响

葡萄着色是葡萄生长过程中的重要环节,对葡萄品质有极为重要的影响。本文以9年生弗雷葡萄品种为对象,研究了新型脱落酸功能类似物萘酮戊酸(natenpac)对田间葡萄果实着色及品质提升的影响。在果实着色初期,以萘酮戊酸有效成分2、5、10 mg/L 3个质量浓度梯度分别进行叶面喷雾、灌根或浸果处理,以清水处理为空白对照。通过对果实平均横径、颜色、单果重等表观变化以及可溶性固形物、花青素、可溶性糖含量等内在品质的变化进行综合分析,以确定最佳的施药方式和浓度。结果表明:以叶面喷雾和灌根处理,萘酮戊酸可使弗雷葡萄较对照提前7~10 d完成着色,显著提高了果实中可溶性固形物含量和着色程度,同时浆果横径和单果重也略有提高。不同处理方式对使用效果影响显著,灌根和叶面喷雾效果优于浸果,其中以叶面喷雾2 mg/L的处理效果最佳。本研究明确了萘酮戊酸对弗雷葡萄的最佳施药方式和剂量,可为指导萘酮戊酸在葡萄着色中的田间应用提供依据。     

影响烟草青枯病发生的关键气象因子分析

烟草是我国重要的经济作物,但随着土壤连作年限的增加,烟草青枯病的发生日益严重,成为制约烟草行业持续健康发展的主要因子.针对烟草青枯病发生与高温高湿的环境条件高度吻合这一现象,本文基于对田间烟草青枯病病情指数以及病害期间气象因子的动态监测,引入最大信息系数和皮尔逊相关性系数评估方法,探究了影响烟草青枯病发生的关键气象因子.结果表明,空气湿度是烟草青枯病发生的必要因子,降雨过后,相对较高的空气温度是促进烟草青枯病发生发展的关键气象因子.当15d平均湿度维持在87.74%以上、15d最低温度维持在13.00℃以上、15d平均温度维持在19.00℃以上时,田间烟草青枯病开始发生;当15d最低温度升高(达到14.83℃以上)时,田间烟草青枯病开始流行;但当日平均温度低于18℃时,病害发生发展速度有所减缓.该结果为今后田间烟草青枯病的预测预报以及病害的及时防控提供了理论支持,在生产上具有一定的价值和意义.     

新疆葡萄枝孢果腐病病原菌的鉴定及生物学特性

2019年在新疆葡萄上发现一种新病害,主要危害成熟葡萄果实。感病果实病部产生橄榄绿色霉层,导致葡萄产量和品质严重下降。为明确该病害病原菌种类及其生物学特性,从南北疆11个葡萄园采集80个病样,用常规稀释分离法和单孢分离法对病原菌进行分离和纯化,根据采集地点、葡萄品种、菌落生长速度等特征选取21个代表性菌株进行形态学鉴定、分子生物学鉴定和致病性测定以明确病原菌种类;并研究了温度、光照、培养基、pH对病原菌生长及产孢的影响。结果表明,引起新疆葡萄果腐病的病原菌为枝孢菌,有两个种,即枝状枝孢Cladosporium cladosporioides和柠檬形枝孢Cladosporium limoniforme,其中枝状枝孢为优势种。两种病原菌的适宜生长和产孢的温度均为25℃,适宜生长和产孢的培养基是PDA,不同光照条件下都可大量产生分生孢子,最适宜生长和产孢的pH为7。明确了新疆葡萄枝孢果腐病病原菌及其生物学特性,为今后该病害的预测预报、发生规律和防治方法的研究打下基础。     

枯草芽孢杆菌防治甜瓜白粉病效果及对甜瓜生长的影响

为探讨枯草芽孢杆菌对甜瓜白粉病的田间防控效果,以50%嘧菌酯水分散粒剂为对照,在甜瓜白粉病初期喷施不同浓度的200亿个活芽孢/g枯草芽孢杆菌可湿性粉剂。调查应用效果发现,该枯草芽孢杆菌制剂与嘧菌酯防效相当。施药处理后14 d,200亿个活芽孢/g枯草芽孢杆菌可湿性粉剂100倍液和500倍液对甜瓜白粉病的防效分别达96.72%和81.40%;对甜瓜株高、叶面横径、叶面纵径、果实横径、果实纵径和果实糖度指标的促生作用分别达24.28%~31.78%、36.85%~50.08%、42.42%~52.21%、61.14%~69.14%、39.58%~49.12%、23.29%~29.86%。     

酿酒葡萄水肥一体化灌溉定额与灌溉布局成本效益分析

为探究河西灌区酿酒葡萄适宜的灌溉定额和灌溉布局，于2019—2021年进行了连续3年田间试验。以‘赤霞珠’酿酒葡萄为供试材料，采取裂区设计，灌溉定额为主区，设置3个灌水水平，即1 800 m³·hm^-2 (低水WL)、2 700 m³·hm^-2(中水，WM)和3 600 m³·hm^-2(高水，WH);灌溉布局为副区，设置3种方式，即1管1行(C-S)、2管1行(C-D)及2管1行分根区灌溉(PRD),探究不同灌溉定额与灌溉布局对酿酒葡萄生长、产量、果实品质及经济效益的影响。结果表明：灌溉定额对酿酒葡萄修剪量、产量、果实品质及葡萄园可变成本具有显著影响，WL处理葡萄果实品质最佳，平均可溶性固形物、多酚及花色苷分别达27.37°Brix、30.69 mg·g^-1及6.74 mg·g^-1;WM处理葡萄产量最高，为10 163.2 kg·hm^-2;WH处理葡萄修剪量最大，为1.53 kg·株     

避雨栽培对葡萄霜霉病发生的影响与葡萄冠层微气象因子的关系

系统比较了云南省石林县(‘红地球’)和弥勒县(‘水晶葡萄’)葡萄园采用避雨栽培和露天栽培对葡萄霜霉病Plasmoparaviticola(Berk.Curtis)Berl.de Toni.的防治效果,监测了田间葡萄园内避雨栽培和露天栽培处理中葡萄霜霉病的发生流行与植株冠层气象因子的变化情况,并结合适宜葡萄霜霉病病害循环的温度、相对湿度、叶面持露时间及田间葡萄植株冠层微气象因子的变化对避雨栽培有效防治葡萄霜霉病的气象原理进行了分析。结果表明,避雨处理可有效控制葡萄霜霉病的发生和危害,石林县和弥勒县两地葡萄园的防治效果分别达到97.84%和66.29%。弥勒县‘水晶葡萄’对霜霉病的抗性较强,霜霉病发生较轻,但在避雨栽培条件下霜霉病的病情指数也显著低于对照。植株冠层微气象因子变化分析表明,避雨栽培可以减少决定霜霉病菌能否成功侵染的叶面水膜持续时间,创造不适宜霜霉病菌萌发和侵入的条件,还可以显著减低棚内植株冠层适宜孢子囊产生的相对湿度的持续时间,减少霜霉病菌的侵染菌量,从而有效地控制了霜霉病的发生和危害。     

行内生草对土壤微环境和酿酒葡萄品质的影响

以宁夏贺兰山东麓主栽的6 a生酿酒葡萄‘赤霞珠’为研究对象,进行了连续2 a行内自然生草(CZR)和人工种植马齿苋(CMC)试验,以清耕(CK)为对照,研究行内生草对土壤温度、容重、总孔隙度、肥力、酶活性、微生物数量和酿酒葡萄果实产量及品质的影响。结果表明:CZR处理与CK处理相比,在酿酒葡萄幼果期、膨大期和成熟期5～25 cm土层平均土壤温度下降0.94、1.12℃和0.93℃,0～60 cm土层平均土壤容重和总孔隙度分别下降2.23%和1.73%,脲酶、蔗糖酶、碱性磷酸酶和过氧化氢酶活性分别提高22.67%、30.26%、8.46%和66.65%,微生物数量提高34.97%;CMC处理与CK处理相比,在酿酒葡萄幼果期、膨大期和成熟期5～25 cm土层平均土壤温度分别下降1.82℃、2.02℃和1.38℃,0～60 cm土层平均土壤容重和总孔隙度分别下降0.90%和2.87%,土壤有机质、碱解氮、有效磷、速效钾、全氮和全磷含量分别提高37.80%、52.67%、31.73%、31.17%、24.81%和21.13%,脲酶、蔗糖酸酶、碱性磷酸酶和过氧化氢酶活性分别提高72.08%、109.67%、14.93%和154.50%,微生物数量提高103.56%;行内生草对酿酒葡萄产量影响不显著,对改善浆果品质有显著作用,CZR和CMC处理较CK处理可溶性固形物含量分别降低1.33%和3.72%,可滴定酸、单宁、总酚和花色苷含量分别提高14.52%和16.13%、21.23%和25.82%、26.65%和24.41%、32.75%和41.16%。在旱区滴灌条件下,葡萄园连续2 a行内生草能够改善土壤物理性状,提升土壤肥力、土壤酶活性和微生物数量,对产量影响不显著,但有利于酿酒葡萄香气物质累积,能调节糖酸比,以行内种植马齿苋效果最优。     

不同节水灌溉技术对香梨地土壤温度的影响

通过对新疆巴州灌溉试验站香梨地在不同灌水技术下土壤温度的监测,分析了不同灌水技术下不同土层深度的温度日变化和日变化趋势。分析结果显示:在5 cm土层深度上,环管、小管和微喷分别比对照温度(25.1℃)平均高出2.3℃、0.8℃和1.5℃。各处理温度增幅均在5 cm表层最大,其大小依次为环管>小管>微喷>对照,最大差值分别是5.5℃、5℃、5℃和4℃。各处理在不同生育期均表现出先增大后减小的趋势,且表层5~10cm土层在花期到坐果期增幅大于其它时期,各处理中环管在不同生育期不同深度土层上的温度均值大于其它各处理,小管和微喷在不同的生育期土壤温度有所差异,而对照在各处理不同生育期不同土层深度上均最小。分析结果表明,采用不同的节水灌溉技术均能改善地温。     

西北半干旱地区葡萄园生草对土壤水分的影响

在生产园行间播种多年生黑麦草、紫花苜蓿、白三叶草,研究其对土壤理化性状和土壤含水量的影响。结果表明:生草可改善土壤物理性状,使土壤容重平均降低5.68%,总孔隙度提高6.15%。同时生草可降低葡萄园土壤水分含量,在葡萄根系生长的土层(0～60cm)范围内,行间种植白三叶草对土壤含水量影响较大,紫花苜蓿影响较小。     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.