核桃栽植技术

1栽植时期核桃Juglansregia栽植时期有春栽和秋栽2种。春栽：春季栽植是在土壤解冻后到春季苗木萌芽前进行栽植。秋栽：秋栽是指秋季苗木落叶后到土壤封冻前进行栽植。秋栽树翌年春萌芽早、生长快且健壮,若有死树,可在来年春及时补栽,从而使全园整齐一致,但应注意栽植后的幼树防寒。核桃幼树栽植后的防寒措施有幼树压倒埋干、树干缠塑料膜、缠尼龙袋、套塑料袋和树干涂聚乙烯醇等,以聚乙烯醇涂干省时方便效果好。     

优质核桃苗木栽植技术

一、栽植时期。秋栽或春栽。二、园地选择。选择土层深厚、有灌溉条件且排水良好的地块,若在山坡栽植,应选择阳坡或半阳坡。     

优种核桃苗木栽植技术

1、栽植时期。秋栽或春栽。 2、园地选择。应选择土层深厚、有灌溉备件且排水良好的地块,若在山坡栽植,应选择阳坡或半阳坡。     

禄劝县核桃丰产栽植技术

总结了禄劝县核桃育苗、嫁接和栽培管理技术以及树形管理和病虫防治等丰产栽培技术。     

平原地区核桃栽植技术

核桃是我国重要的经济林树种,但过去多在荒山荒沟、丘陵地区栽植。本文从核桃的生长发育基本特点、育苗栽植以及主要病虫害防治等方面介绍了平原地区核桃生产的主要技术。     

西安市良种核桃精细栽植管理技术

在核桃栽植中,除实施“四大一膜”技术外,试验分析表明选择木质化程度高苗木、栽植回填熟土、秋栽双层套干、合理间作套种、可控根容器培植补苗、无公害防治等精细栽植与栽后管理技术,对于提高栽植成活率,促进栽后第一年生长发育,效果十分显著.     

核桃秋季栽植技术要点

核桃是甘肃省华亭县林果产业发展的拳头产品,栽培历史悠久。据县志记载,在明代就有栽培。为此,华亭县委、县政府充分发挥区域资源优势,把核桃产业作为促进新农村建设的一项支柱产业来抓,从1999年开始,历经10余年时间,截至     

核桃栽植管理技术

一、栽植地块选择 选择平坦和向阳开阔的缓坡地,要求土层厚1米以上,土壤深厚、疏松、肥沃,具备一定的灌溉条件。     

浅析提高渭北旱塬核桃栽植技术措施

核桃是渭南市主要经济林树种之一,是渭北旱塬和秦岭北麓地区退耕还林、群众增收致富的首选树种。为了有效提高核桃建园质量,从园址选择、提前整地、品种及苗木选择、授粉树配置及栽植技术等方面提出具体措施。     

清香核桃幼树栽植管理技术

<正>清香核桃20世纪80年代初由河北农业大学从日本引进。经过河北农大多年的试验观察,该品种表现出:健壮的生长势,出众的丰产性,美观的坚果外形和优异的种仁品质,是优质商品核桃生产的理想品种。清香核桃幼树生长旺盛,1至3年生幼树易受早霜     

不同核桃品种花粉生活力的比较研究

用TTC染色法和培养基法测定了香玲、上宋、中林1号、岱香4个核桃品种花粉生活力和萌发率。结果表明,核桃不同品种花粉生活力存在显著差异,岱香和上宋花粉生活力极显著高于香玲,显著高于中林1号;各品种花粉发芽率在同一种培养基上,以岱香最高,其次是上宋和中林1号,香玲最低;4个品种均以在低糖、高硼酸培养基中即“5%蔗糖 0.5%硼酸”上花粉发芽率最高,显著或极显著高于其他培养基上的发芽率;在“10%蔗糖 0.5%硼酸”和“15%蔗糖 0.5%硼酸”培养基上花粉发芽率均为0。     

核桃花粉人工采收方法比较研究

比较了干燥剂、日晒、阴干三种不同采收方法处理核桃花序,经分析花粉的品质,干燥剂处理花粉的品质较优,阴干次之,日晒采集的花粉品质较差。     

西藏核桃研究进展及发展趋势

在综述西藏核桃的起源、分布、坚果特性、遗传多样性及引种栽培等方面的研究进展的基础上,结合西藏核桃发展需求,探讨西藏核桃的发展趋势,可为西藏核桃产业的可持续发展和进一步的研究工作提供参考。     

Botryosphaeriaceae species causing canker and dieback of English walnut (Juglans regia) in Italy

English walnut (Juglans regia) is an important nut crop worldwide and is currently considered emerging in Italy. Botryosphaeriaceae fungi cause symptoms including cankers, discoloration and dieback, and several species are reported across the world on walnut. In this study, symptomatic trees from an orchard in Southern Italy showing branch dieback, cankers, wood discoloration and gummosis were surveyed. Three different fungi from the Botryosphaeriaceae were consistently isolated from symptomatic tissues. Representative isolates were characterized using morphological and molecular approaches based on conidial morphology, optimum growth temperature and the comparison of DNA sequence data from the ITS, tef1‐α and tub2 loci. Three species were identified: Botryosphaeria dothidea, Neofusicoccum mediterraneum and Neofusicoccum parvum. Pathogenicity tests on detached fruits and potted plants showed that all three species were pathogenic. To our knowledge, this is the first report of these Botryosphaeriaceae species causing canker and dieback on English walnut in Italy.     

Soil physical characteristics and understory management in a walnut (Juglans regia L.) plantation in central Italy

Early and significant influences on soil physical properties are expected in temperate agroforests as a consequence of various soil and/or understory management practises. Soil physical characteristics were studied in an agroforestry trial of common walnut (Juglans regia L.) set up on a volcanic soil in central Italy, where clean cultivation, polyethylene mulching along tree rows and intercropping of walnut with alfalfa (Medicago sativa L.) were tested. Soil total porosity, size distribution and morphology of pores, and available water were evaluated during the second and the fourth growing season of the plantation to determine the possible influence and duration of the treatments on soil physical properties. In the first sampling the total porosity was two to three times greater than in the second one and no significant differences were found between treatments. Seasonal variation in total porosity was observed, with a maximum in summer. All dimensional classes of pores > 50 μm were well represented, thus indicating an adequate soil structure. In the fourth growing season total porosity and pore size distribution were very similar in clean cultivation and mulching so that the mulching effect on the structural characteristics of this soil was equivalent to that of repeated rototilling in clean-cultivated plots. Moreover, mulching stimulated more biological activity, resulting in a higher proportion of rounded pores. Alfalfa roots created a more homogeneous environment to a depth of 35 cm, with a greater presence of elongated pores in the range 50--500 μm that could make movement of water easier. Most of the water retained was unavailable for plants, so that competition between walnuts and alfalfa took place and could be associated with the lower stem growth of intercropped walnuts. This revised version was published online in June 2006 with corrections to the Cover Date.     

复合抑制剂对核桃青皮多酚氧化酶活性的影响

为给核桃采摘、生产及加工中褐变现象的抑制提供理论参考依据,从核桃青皮中提取多酚氧化酶(PPO),采用光谱法研究了不同抑制剂及其复合物对其PPO活性的影响情况。单因素试验结果显示:不同抑制剂对核桃青皮PPO酶活性的影响差异明显,亚硫酸钠(Na_2SO_3)、氯化钠(Na Cl)、L-半胱氨酸(L-Cys)、芦丁对核桃青皮PPO活性的最适抑制浓度分别为0.3、0.6、0.3、0.3 mol/L,其中,L-Cys对其PPO活性的抑制效果最为显著。正交试验结果表明:以0.4 mol/L的Na_2SO_3、0.5 mol/L的Na Cl、0.2 mol/L的L-Cys和0.8 mol/L的芦丁配制的复合液对其PPO活性的抑制效果最好。文中综合分析认为,核桃青皮PPO是引起其酶促褐变的主要影响因素,在核桃采摘、生产及加工中可通过添加L-Cys或多种抑制剂的复合物来抑制其PPO活性。     

Genotype and environment: two factors related to autumn cold hardiness on Persian walnut (Juglans regia L.)

Context

J. regia timber is appreciated for high-value wood products. In new plantations, biotic or abiotic events which could affect wood quality should be monitored. Autumn frosts could affect annual shoot development, with consequent loss of timber value or even tree death. In southern Europe, climate change forecasts include erratic and severe autumn frost events.

Aims

The relationship between genotype and environment regarding susceptibility to autumn frost damage was examined in four provenances of Juglans regia L., planted at two ecologically different sites, one subject to Mediterranean and the other Atlantic weather conditions.

Methods

Annual budsticks from eight trees per provenance were collected in November 2010 from each site. The samples were then submitted to freeze–thaw cycles down to ?8, ?13 and ?18 °C, plus a control treatment (keeping samples at 5 °C). Damage to the stem was assessed using the index of freezing injury calculated from relative electrolyte leakage at each temperature considered. Frost damage to stem, apical and lateral buds was recorded by visual scoring.

Results

Differences in cold acclimation between sites were detected, with provenances exhibiting differences on senescence. A ‘provenance?×?site’ interaction was found in some of the analyses, but the same ranking of susceptibility was detected for all provenances at both sites and in all the tissues analysed. The differences between provenances could be related to their geographical origins, where an altitude gradient was observed.

Conclusions

The genetic component was important in the expression of autumn cold hardiness and, together with productive traits, should be considered in new afforestation projects.     

核桃嫁接技术研究

以香玲、鲁光等早实薄壳核桃为试材,通过5年的嫁接试验研究,结果表明：中部饱满芽萌发时间短,成活率高,成活后生长速度较快;规模化生产最佳嫁接时间为春分前10天至清明后5天;接穗树龄越小,亲和力越强,成活率越高;覆盖黑色微膜能促进早生快发,抑制杂草。就近建立采穗圃,采用枝接与芽接相结合的方式,成活率能达到96%,产业化发展成活率达到88%以上,合格苗出圃率在80%以上。     

Resistance evaluation of walnut (Juglans spp.) against Xanthomonas arboricola and the correlation between leaf structure and resistance

Walnut blight caused by Xanthomonas arboricola pv. juglandis (Xaj) is one of the most detrimental diseases affecting walnut quality and production. A screen of 18 walnut genotypes for leaf resistance to Xaj suggested species independent variation and revealed four highly resistant (HR) cultivars (‘96’, ‘91’, ‘Chuanzao2’ and ‘Qingxiang’), while ‘Yanyuanzao’ and ‘Xiangling’ were highly susceptible (HS). Further correlation analyses were carried out on the 18 genotypes. Stomata length (SL) (r = .686, p < .05) and stomatal area (SA) (r = .596, p < .05) had significant positive correlations with disease severity index (DSI), suggesting that the length and density of stomata affected the speed and number of pathogens invading the leaves. The highly susceptible genotypes had a significantly lower thickness ratio of spongy to palisade tissue (P/S) (1.50). When compared to resistant genotypes (1.69), the P/S value had a significant negative correlation with the DSI (r = ?.631, p < .05). Denser spongy tissue and more developed palisade tissue were indicative of higher resistance for the genotype. The stomata breadth (SB), stomata density (SD) and wax content (WC) each had no correlation with resistance. Maximum SW, SD and TU and minimum WC were found in HS genotypes, such as ‘Xiangling’ and ‘Yanyuanzao’. The leaf thickness (LT), the thickness of the abaxial epidermis (TL), the thickness of stratum corneum (LCT), the tissue structure tense ratio (CTR) and tissue structure loose ratio (SR) did not correlate with resistance. These findings not only provide information to facilitate our understanding of Xaj resistance but also lay the foundation for breeding Xaj‐resistant walnut in the future.