基于根域限制的葡萄小麦套种模式对小麦小气候环境与经济效益的影响

研究了基于根域限制的葡萄小麦套种模式对小麦小气候环境及生长产量的影响。结果表明,套种葡萄对小麦冠层温湿度的影响不显著,对小麦冠层整体遮阴程度仅为20%,且根域限制种植不影响小麦的水肥资源。套种葡萄对小麦旗叶的光合速率影响较低,在小麦区域边缘处每靠近葡萄10 cm,CO_2光合速率下降约0.26μmol/m~2/s,且套种葡萄不会影响小麦的营养生长和生殖生长。与对照相比,套种小麦的单位面积产量降低15%,净收入提高8.4倍。因此,基于根域限制的葡萄小麦套种是一种对小麦影响较弱,提升经济效益能力极强的套种模式。     

Shade stress decreases stem strength of soybean through restraining lignin biosynthesis

Lodging is the most important constraint for soybean growth at seedling stage in maize-soybean relay strip intercropping system. In the field experiments, three soybean cultivars Nandou 032-4 (shade susceptible cultivar; B1), Jiuyuehuang (moderately shade tolerant cultivar; B2), and Nandou 12 (shade tolerant cultivar; B3) were used to evaluate the relationship between stem stress and lignin metabolism in the stem of soybean. Results showed that the intercropped soybean was in variable light condition throughout the day time and co-growth stage with maize. The xylem area and cross section ratio played a main role to form the stem stress. The B3 both in intercropping and monocropping expressed a high stem stress with higher xylem area, lignin content, and activity of enzymes (phenylalanine ammonia-lyase (PAL), 4-coumarate: CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD)) than those of B1 and B2. Among the soybean cultivars and planting pattern, lignin content was positively correlated with stem stress. However, a negative correlation was found between lignin content and actual rate of lodging. In conclusion, the shade tolerant soybean cultivar had larger xylem area, higher lignin content and activities of CAD, 4CL, PAL, and POD than other soybean cultivars in intercropping. The lodging in maize-soybean intercropping can be minimized by planting shade tolerant and lodging resistant cultivar of soybean. The lignin content in stem could be a useful indicator for the evaluation of lodging resistance of soybean in intercropping and activities of enzymes were the key factors that influence the lignin biosynthesis.     

山地密植苹果园间作模式及效益研究

１９９２￣１９９５年对五莲县松柏乡王家口子村８ｈｍ＾２密植苹果园的间作物，进行了“五作四收”立体种植研究。结果表明，试验园苹果树定植的当年即可收回果园的全部投资。并且每公顷盈利２７０６８．８元。试验园２ａ平均一级果率９６．８％，平均单果重２３６．８ｇ，果实着色指数７３．８％，可溶性固形物含量７８．７％。试验园４ａ平均每公顷纯收入２７４１７．３５元，是４ａ平均每年每公顷投资（８８１８．５元）的３．１     

甘蔗间作籽粒苋的试验研究

设对照组、试验组２次重复进行对比试验，对照组小区播种ＣＯ７４０甘蔗品种，试验组小区间作籽粒苋 。试验组结果表明，试验组生物量（鲜重）１４２５９．６公斤，试验线的干物质、精蛋白质、粗纤维、无氮浸出物、粗脂肪含量比对照组分别提高１９．８％、２４．１％、２０．５％、１８．２％、１９．２％。ｔ值测定Ｐ＜ ０．０５。     

Microsatellite primers indicate the presence of asexual populations of<Emphasis Type="Italic">Venturia inaequalis</Emphasis> in coastal Israeli apple orchards

This study was initiated to determine whether differences in genotypic diversity among populations ofVenturia inaequalis (Cke.) Wint., as detected using neutral genetic markers, were related to the ecological conditions in which apples are grown in Israel. Since sexual reproduction in this fungal pathogen has an obligate requirement for sustained low winter temperatures, and since these requirements in Israel are met only on the Golan Heights, we were interested in whether lower elevation populations of this pathogen might be comprised of asexual clonal lineages. Unlike temperate apple growing regions, where the primary spring inoculum is ascosporic derived from overwintered pseudothecia, Israeli apple orchards at lower elevations in the Hula Valley and along the coastal plain rarely if ever experience low winter temperatures and pseudothecia have never been recovered. Two orchards were sampled from the Golan Heights (El Rom and Ortal, n=38) and three orchards from the Hula Valley and coastal plain (Sede Eliezer, Ginaton and Be’er Tuvia, n=40). Microsatellite primers were used to analyze population structure and the resulting binary data analyzed by both cluster and parsimony analysis. Populations from the coastal plain were genetically uniform within each of the orchards sampled, whereas populations from the Golan Heights showed levels of genotypic diversity ten times as high. The data support field observations that this pathogen does not reproduce sexually in regions characterized by the absence of low winter temperatures and is instead composed of clonal lineages. This may have bearing on control strategies for the disease in Israel. http://www.phytoparasitica.org posting April 21, 2003.     

Combining physical, cultural and biological methods: prospects for integrated non-chemical weed management strategies

Physical, cultural and biological methods for weed control have developed largely independently and are often concerned with weed control in different systems: physical and cultural control in annual crops and biocontrol in extensive grasslands. We discuss the strengths and limitations of four physical and cultural methods for weed control: mechanical, thermal, cutting, and intercropping, and the advantages and disadvantages of combining biological control with them. These physical and cultural control methods may increase soil nitrogen levels and alter microclimate at soil level; this may be of benefit to biocontrol agents, although physical disturbance to the soil and plant damage may be detrimental. Some weeds escape control by these methods; we suggest that these weeds may be controlled by biocontrol agents. It will be easiest to combine biological control with fire and cutting in grasslands; within arable systems it would be most promising to combine biological control (especially using seed predators and foliar pathogens) with cover‐cropping, and mechanical weeding combined with foliar bacterial and possibly foliar fungal pathogens. We stress the need to consider the timing of application of combined control methods in order to cause least damage to the biocontrol agent, along with maximum damage to the weed and to consider the wider implications of these different weed control methods.     

低氮环境下燕麦与箭豌豆间混作与刈割时间对饲草产量及质量特性的影响

对北京市延庆县旱作低N土壤环境下燕麦与箭豌豆间混播6种方式与比例对饲草产量与质量特性影响进行了研究。结果表明,在低N环境下,与燕麦单作相比,箭豌豆与燕麦间混播不仅可增加饲草中干物质产量,饲草N产量也可增加30%~130%;而且燕麦与箭豌豆间混作对饲草质量也有显著影响(P<0.01)。间混作能够降低饲草中ADF与NDF含量,提高燕麦开花后饲草RFV值。4种间混作处理在饲草产量与饲草品质方面各有优点,也各有不足。在低N环境下,如果以饲草产量和饲草N产量为主要追求目标,则燕麦与箭豌豆1∶1邻行间作方式为最佳播种模式,其次依次分别是燕麦与箭豌豆1∶1同行混播、燕麦与箭豌豆1∶2同行混播、燕麦与箭豌豆2∶1同行混播。燕麦与箭豌豆间混播最佳刈割期为燕麦乳熟期 箭豌豆满荚期,因为此时混合饲草产量最高,饲草N产量与RFV较高,而ADF与NDF较低。     

京郊休闲果园游客满意度调查研究

随着北京郊区休闲果园的快速发展，客源市场的竞争日趋激烈，提高游客的满意度对于稳定客源市场、增强果园的竞争力具有十分重要的意义。笔者通过对到京郊休闲果园游玩的国内游客的问卷调查，分析了其社会人口学特征与其消费行为特征、满意度的关系，并在此基础上得出了相关结论，提出了提高果园游客满意度的一些建议。     

影响杉木种子园良种产量的主要害虫及综合治理对策

在福建省洋口林场杉木种子园中常见的害虫有２６种，隶属７目２０科。其中杉木球果麦蛾、杉木扁长蝽和杉梢小卷蛾是影响良种产量的主要害虫。杉木球果麦蛾是中国新记录种，以幼虫危害球果的苞鳞、果轴及种子，使球果变色、干枯。杉木扁长蝽的危害及炭疽菌和散斑壳菌的侵染导致球果变色。１０月受害果率达３７．２％。测定结果表明，球果虫害及变色明显影响每百球果的鲜果重、种子重、千粒重及出籽率（平均下降２６．９％—７３．７％），但对种子的发芽率及涩籽率无显著影响，并提出以摘尽球果为主的综合治理措施。     

Using plant architectural models for estimation of radiation transfer in a coconut-based agroforestry system

Software modules have been developed to predict the radiative environment of plant stands consisting of computer 'mock-ups' of plants. The architecture of plants used for the computation of radiative characteristics was described at the level of individual organs and simulated according to botanical rules. Three-dimensional stochastic numeric mock-ups were computed for coconut (Cocos nucifera L.) and for cacao (Theobroma cacao L.) according to the 'AMAP' methodology. Then the numerical radiative models were applied to these 'virtual plants' to describe the radiative budgets of individual plant parts and entire plants. Modelled light transmission through virtual coconut canopies was in good agreement with field measurements for different treatments and management practices including palm ages, varieties, and planting densities. In a second stage, combining the computer models of coconuts and cacao in a multistrata system, the fraction of radiation that was transmitted through the coconut canopy and intercepted by cacao was sucessfully simulated. This revised version was published online in June 2006 with corrections to the Cover Date.