核桃主要病虫害的发生与防治

核桃主要病虫害的发生与防治李东鸿，刘志刚（陕西省农科院植保所，陕西杨陵７１２１００）王善政，冀宏山（洛南县核桃研究所，陕西洛南７２６０００）近年来，洛南核桃病虫害的发生与危害日趋严重，直接影响产量、品质和果农的经济收入。据统计，全县每年由于病虫危害损...     

核桃扁叶甲指名亚种的发生与防治

核桃扁叶甲指名亚种（Gastroiina deprssa deprssa Baly） ，属鞘翅目叶甲科，是危害枫杨的主要食叶害虫之一。青阳县2003年4月首次发现该虫，经安徽农业大学昆虫学教授杨春材鉴定。由于尚未发现其发生、危害特点及防治措施等相关资料，自2003年以来，笔者对核桃扁叶甲指名亚种连续进行了观察、调查和防治试验，初步掌握了核桃扁叶甲指名亚种的生物学特性、发生危害特点及防治方法。     

两种核桃蚜虫危害对核桃光合特征的影响

[目的 ]明确核桃黑斑蚜和核桃全斑蚜危害对不同生长期核桃叶片光合作用的影响。[方法 ]在核桃的速生生长期、硬核期和脂化期,利用便携式叶绿素测定仪(SPAD-502plus)和LI-6 400便携式光合作用系统测定了核桃不同生长时期受到不同密度的两种核桃蚜虫危害不同时长后叶片的SPAD值、光合速率(Pn)、蒸腾速率(Tr)等光合特性指标,并测定了受不同核桃蚜虫危害后的核桃果实质量、出仁率等。[结果 ]在速生生长期受到核桃黑斑蚜或核桃全斑蚜短期危害1～5 d,核桃叶片SPAD值无显著差异,而在硬核期和脂化期受核桃黑斑蚜、核桃全斑蚜和混合蚜虫危害均导致叶片SPAD值呈下降趋势。两种核桃蚜虫危害后核桃叶片的光合速率(P_n)和蒸腾速率(T_r)均显著下降,且蚜虫密度不同下降程度不同。受核桃黑斑蚜和核桃全斑蚜危害后核桃单果质量(青皮)和干果质量均呈下降趋势;受不同种类蚜虫危害后的核桃出仁率均出现下降。[结论 ]蚜虫危害对核桃叶片光合作用产生负面影响,导致核桃果实出仁率下降。因此,对两种核桃蚜虫的防治应该采取紧急措施,以保护核桃产量和质量。     

山阳县"核桃黑"成因初步调查及防治策略

对山阳县不同立地条件下的"核桃黑"进行了调查,明确了"核桃黑"主要由核桃举肢蛾、核桃黑斑病、炭疽病、桃蛀螟等病四种虫危害所致.当地深山区以核桃黑斑病危害为主.浅山区以黑斑病和举肢蛾为主,并有零星的桃蛀螟危害.平川区以举肢蛾为主,黑斑病危害次之,桃蛀螟危害严重.提出了综合防治措施.     

汉源人工核桃林主要病虫害调查

本文以四川汉源县核桃为对象,开展核桃病虫害调查,获得以下主要结果:汉源县核桃有害生物共计30种,其中危害较为严重的虫害为云斑天牛、木橑尺蠖、黄刺蛾、桃蛀螟、核桃举肢蛾等,病害普遍发生的是核桃炭疽病、核桃黑斑病、核桃缩叶病,具有潜在危害性的较大的是核桃木腐病、核桃枝枯病、核桃溃疡病和星天牛、茶丽天牛等对核桃枝干危害的有害生物。调查发现核桃有害生物种类随着温度的变化呈现周期性变化。汉源县4月气温10~30°C时虫害开始危害植株,病害也开始侵染植株,并随温度升高,种类增多,危害加重。11月气温10~20°C时有害生物危害降低,开始越冬。核桃有害生物种类以及危害程度与其种植环境有关。四旁树核桃、核桃和玉米混合种植有害生物危害较核桃纯林严重,核桃柑橘混合种植时有害生物种类较核桃纯林种类多,这可能与混栽植物间有共同有害生物有关,有关机理将进一步研究。     

核桃小吉丁虫危害及防治技术

指出了核桃小吉丁虫属鞘翅目吉丁虫科,是危害枝干的害虫,分布于全国各地,主要危害核桃、桃树、杏树等果树。通过对岐山县核桃经济林连续三年的调查,掌握了核桃小吉丁虫危害的特点,并提出了防治措施及建议,为今后防治核桃小吉丁虫提供技术依据。     

盐亭县核桃有害生物种类及防治建议

采用踏查和标准地调查相结合的方法,于2017年对盐亭县核桃有害生物种类、分布范围和危害程度进行了系统调查。结果表明:危害核桃的虫害有13种、病害5种、有害植物2种。主要有害生物有核桃举肢蛾、核桃长足象、云斑天牛、核桃黑斑病、核桃褐斑病、核桃炭疽病等。本文分析了盐亭县核桃主要有害生物危害特点及防治现状,并提出防治建议。     

建立采穗圃是核桃良种繁育的重要举措

云南是核桃原产地之一。由于得天独厚适宜核桃生长的自然环境,云南核桃种质资源十分丰富。目前,云南主要栽培的优良品种（品系）有漾濞泡核桃（又称大泡核桃、泡核桃、茶核桃）、大桃三台核桃（又称草果核桃）、细香核桃等,这些传统的优良品种以其优良的品质而享誉国内外。良种的保有是云南核桃产业得以迅猛发展的前提和基础,良种繁育和推广始终是产业发展的关键性问题。切实解决核桃良种繁育问题是实现云南发展3000万亩核桃,建立核桃优势产业的重要保障措施。     

我国核桃光合作用研究进展

综述了近几年来我国核桃光合作用的研究进展,主要从核桃光合作用研究植物试验材料的选择,光合作用El变化、季节变化,影响核桃光合作用的内在因子（品种、砧木、叶片等）、外在因子（光照、温度、矿质元素等）等几方面对我国核桃光合作用特点进行了分析总结,并提出了核桃光合作用研究重点及方向。     

核桃举肢蛾防治

核桃是山西省阳泉市的优良乡土树种之一,但树龄在20年以上的核桃大树多年来遭受核桃举肢蛾的危害,造成了果实品质较差、产量低,严重影响了核桃的经济效益,为此,我们对核桃举肢蛾进行了多年的观察和防治。核桃举肢蛾属鳞翅目,举肢蛾科,别名为核桃黑。寄主植物以核桃为主,也能危害核桃楸,在阳泉市一年发生一代,以老熟幼虫于表土结茧越冬。此害虫以幼龄幼虫蛀入核桃果内,蛀孔外出现白色胶珠,后变琥珀色。随着幼虫生长,纵横穿食危害,隧道内充满虫粪,被害果皮皱缩,逐渐变黑,并开始凹陷,核桃仁发育不良,出现干缩而变黑。有的幼虫直接危害核桃仁,使…     

美国东部黑核桃与核桃的嫁接亲和力研究

通常对核桃和美国东部黑核桃嫁接的成活率进行比较,证明美国东部黑核桃和核桃具有很强的嫁接亲和力,为将来利用美国东部黑核桃做为核桃嫁接砧木提供了有力的证据。     

A review of suitable companion crops for black walnut

Black walnut (Juglans nigra L.) is a temperate tree grown for nuts and wood, but it is allelopathic to certain plants and animals. We compiled reports of valuable black walnut companion crops which may be grown in the short term (<15 years after planting walnut trees), medium term (15–30 years), and long term (>30 years). There are many black walnut companion cropping systems for the short and medium term, but there are few for the long term. Companion crops for black walnut serve multiple functions, including nitrogen fixation, added yields, the development of straight walnut stems, and added protection from forest pests such as deer. Black walnut polyculture is a viable alternative worthy of further development and implementation.     

两种核桃砧木的生长发育规律及耐涝性分析

对铁核桃、黑核桃生长发育规律及耐涝性进行了分析,结果表明:(1)与铁核桃相比,黑核桃萌发期偏迟,但新稍封顶早、落叶早。(2)铁核桃在整个观测期生长迅速,5—6月生长速度最快,而黑核桃主要生长期集中在5—7月,7月中旬以后生长量偏小;(3)极端高温天气、水分不足是黑核桃在引种区生长较差的主要因素;(4)黑核桃耐涝性强于铁核桃。     

浅析美国黑核桃嫁接栽培技术及发展前景

美国(东部)黑核桃是一种果材兼用的落叶乔木树种,生长适应能力强,可作为经济林树种、用材树种和生态树种。文章主要介绍了黑核桃的栽培历史、生产应用、主要特性、嫁接技术及发展前景,为山西省今后黑核桃的发展,提供了重要的参考和依据。     

Growth response of black walnut to interplanted trees

Analyses of black walnut tree diameters 13 years after planting showed that interplanting autumn-olive, black locust, and European alder increased walnut tree growth, but only at certain locations. Interplanting autumn-olive resulted in increases of 56 to 351% at four of five locations and all species resulted in doubled walnut growth on an upland site. The interaction between treatment and location indicates that a fuller understanding of site and nurse species characteristics is needed to obtain the potential benefits of mixed plantings.     

核桃细菌性黑斑病发病规律及防治技术研究

核桃细菌性黑斑病是陕西洛南核桃树的主要病害之一。试验研究表明,根据该病发病规律,在抓好林业防治的基础上,采用林业防治、化学药剂防治相结合的综合防治技术,防治效果明显。     

Juglone (5-hydroxy-1,4 napthoquinone) and soil nitrogen transformation interactions under a walnut plantation in southern Ontario, Canada

Juglone (5-hydroxy-1,4-naphthoquinone), a chemical substance produced by black walnut (Juglans nigra L.), inhibits the growth and existence of some beneficial soil microorganisms, especially Frankia spp. isolate ArI3 and Rhizobium japonicum. However, no studies to date have reported on the effect of juglone on soil ammonification and nitrification. A field study and laboratory incubation study to investigate this were conducted. In the field, in situ soil ammonification and nitrification were measured within and outside of a 60-year-old black walnut plantation and a eight-year-old poplar (Populus spp. clone DN 177) plantation. In the lab, soil (Sandy Fox Loam), collected in the absence of black walnut trees, was incubated for periods of one to six weeks in the presence of varying concentrations of juglone. In the field, peak summer mean nitrate accumulation rates in soils within the black walnut and poplar plantation were 163 and 95 μg 100 g^-1 dry soil day^-1 respectively and in soils outside the plantations, 104 (black walnut) and 78 (poplar) μg 100 g^-1 dry soil day^-1 respectively. No accumulation of ammonium at the end of the incubation period was noted. Therefore, no inhibition effect of juglone on nitrification in the field was observed, and laboratory incubation results confirmed the results of the field study. Results from these studies should address concerns about nitrification inhibition under walnut based intercropping systems. This revised version was published online in June 2006 with corrections to the Cover Date.     

Drought tolerance,xylem sap abscisic acid and stomatal conductance during soil drying: a comparison of young plants of four temperate deciduous angiosperms

Patterns of water relations, xylem sap abscisic acid (ABA) concentration ([ABA]) and stomatal aperture were compared in drought-sensitive black walnut (Juglans nigra L.) and black willow (Salix nigra Marsh.), less drought-sensitive sugar maple (Acer saccharum Marsh.) and drought-tolerant white oak (Quercus alba L.). Strong correlations among reduction in predawn water potential, increase in xylem sap [ABA] and stomatal closure were observed in all species. Stomatal response was more highly correlated with xylem [ABA] than with ABA flux. Xylem sap pH and ion concentrations appeared not to play a major role in the stomatal response of these species. Stomata were more sensitive to relative changes in [ABA] in drought-sensitive black walnut and black willow than in sugar maple and white oak. In the early stages of drought, increased [ABA] in the xylem sap of black walnut and black willow was probably of root origin and provided a signal to the shoot of the water status of the roots. In sugar maple and white oak, leaf water potential declined with the onset of stomatal closure, so that stomatal closure also may have occurred in response to the change in leaf water potential.     

Seasonal changes in nodular nitrogenase activity of Alnus glutinosa and Elaeagnus angustifolia

Root nodule development, and seasonal patterns of nodular nitrogenase and hydrogenase activities were determined for 5- to 8-year old black alder (Alnus glutinosa (L.) Gaertn.) and Russian olive (Elaeagnus angustifolia L.) interplanted with black walnut (Juglans nigra L.) on bottomland and upland sites in central Illinois, USA. Black alder produced nodules at both sites, but Russian olive did so only at the bottomland site. Nodular nitrogenase activity was detectable in both species over a 220-day period. Maximum, midday rates of nitrogenase activity (acetylene reduction) of 15 to 20 micromoles C(2)H(4) per g dry nodule per hour were maintained by black alder for approximately 150 days at both the upland and bottomland sites. Near maximum rates of nodular nitrogenase activity were maintained for a similar period by Russian olive at the lowland site, although specific nitrogenase activity was approximately 25% lower than in black alder owing to a larger proportion of necrotic nodular tissue in Russian olive. In both species, nitrogenase activity increased exponentially with temperature between 10 degrees C and 20 to 25 degrees C. No net hydrogen evolution by nodules of either species was detected at any time during the assay period, indicating efficient hydrogenase systems were operating under the conditions of the field assay. Height of black walnut interplanted with nodulated black alder and Russian olive was greater than that of black walnut grown in pure stands.     

Weed control and autumn-olive affect early growth and survival of black walnut in a hardwood clearcut

Eight years after planting in a hardwood clearcut, black walnut trees in plots with weed control had significantly better survival and were taller and larger in diameter than those in plots without weed control. Planting autumn-olive with walnut also significantly increased height and diameter of the walnuts but did not affect their survival.