主干形是一种高光效、省工、高产树形,在桃树生产中表现很好,值得推广.该文介绍了桃树主干形1～3年整形修剪技术,以供参考.

随着人们生活水平的提高和果品总量的增加,对苹果果品质量的要求也越来越高,既要内在品质好,汁液丰富,酸甜可口——好吃;还要外观漂亮——好看(买得欢心);还得无污染——安全(吃得放心).收购商按质论价,优果优价,好果供不应求,劣果难卖,苹果产业不再是只追求产量的时代了.2017年“烟台苹果”盛产区蓬莱市富士苹果因品质好每千克收购价12元多,栖霞、招远等县市每千克苹果只卖到6元,效益相差一半(图1).

众所周知,苹果小叶病是缺锌导致的生理病害.笔者近日考察陕甘宁鲁豫皖等苹果产区时发现,苹果小叶病在各地都有发生,尤其幼龄果园发生偏重.据观察分析,笔者认为导致苹果发生小叶病的主要原因,不是单纯的土壤缺锌,而是与土壤状态、地面及树上管理都有关系.现将小叶病发生的主要原因与防治措施总结如下: 1 小叶病发生的主要原因

随着大化肥在果树生产中的广泛使用,施肥效果越来越差,果品质量不升反降,果实苦痘病、痘斑病、鸡爪纹、皴皮、裂口,及由缺钙引起的红点病、黑点病等缺钙生理病害大量发生.果园土壤酸化,果树根系生长受限,果树根系的新生根少, 根尖褐化, 根系吸收钙的能力大大下降.2016～2017年,经过试验,在果园中施用富含钙、镁、硅的酸化土壤改良剂波美度,一方面调整土壤pH值,改良了土壤环境,促进了果树根系的生长, 吸收钙功能强的乳白色新生根尖数量明显增多,同时又向土壤中补充了钙.

2018年春天,苹果开花时发现,不少果园满树不见几个花.人们开始疑惑,去年冬剪的时候,明明看到好多芽子都挺饱满的,花芽很多,怎么转年春天发芽后却不见花,花芽变成了谎花(图1)?为此笔者探讨了2018年为何开花少,谎花多的原因,并就如何做到来年花满头,提出建议.

矮化密植栽培具有成形快、早果性强、树冠小、适合密植、单位面积产量高、适合机械化作业、降低果业用工等优点,尤其是在当前果树管理用工短缺、人工费用不断上涨的情况下,降低果业生产成本,实行省力化栽培,提高产品竞争力,成为果树栽培模式转型和产业升级的关键切入点.烟台现代果业科学研究院示范园栽植M9T337自根砧神富一号(烟富8)苹果取得了定植第1年667 m2产量700 kg,第3年丰产,667m2达到2 500 kg.

苹果品种更新换代及老果园更新改造,已成为产业发展当务之急.烟台现代果业科学研究院以选育推广优良品种为目标,选育出短枝红色双芽变苹果新品种——神富6号. 1 选育经过 2003年秋天,烟台海阳市富士园中发现有一株短枝性状明显、叶片肥厚浓绿、抗病性好、果实着色早、上色快、果个大、果形高桩、抽枝能力强、容易形成花芽的单株.

A combination approach of field surveys,indirect ELISA and electron microscopy was carried out to provide accurate information on the distribution of Polymyxa graminis transmitted wheat mosaic viruses in China during 2008-2010.The results showed that serious disease had spread westward and northward in Chinese winter wheat growing regions during the last decade.Wheat yellow mosaic virus was found for the first time at Taian（Shandong province）,Shangqiu（Henan province）,Danjiangkou,Xiangfan and Suizhou（Hubei province）.Neijiang was the only area where the disease observed in Sichuan province.The complex infection of WYMV and Chinese wheat mosaic virus（CWMV） has become more serious in Jiangsu province.WYMV and CWMV had disappeared from Zhejiang province.Cultivation of resistant wheat varieties is the only economic mean to control the diseases,so it is necessary to evaluate the resistance of wheat varieties for their further use in wheat production.

Under the condition of field cultivation,the effects of foliar-spraying of different concentration of prohexadione calcium on the physiological characters of root and leaf of peanut (Arachis hypogaea L.) were studied. Results indicated that prohexadione calcium could improve promptly the activity of root system and chlorophll content of leaf,enhance the activities of superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and the content of soluble protein (Pro) in root and leaf of peanut,decrease the content of propyldialdehyde (MDA) of leaf and root. Prohexadione calcium can markedly reduce plant height and pod number per kg,increase pod number per plant,the ratio of seed to pod,pod yield and protein content. The effect of lower concentration (30 g·hm-2) was more efficient than that of higher concentration (60 g·hm-2).