春伐桑树不同伐条部位与桑叶产量的关系

通过春伐桑树不同伐条部位对产叶量影响的初步试验表明,在其它桑园管理措施一致的前提下,采取距离一年生枝条基部4～6 cm处（留芽2～3芽）伐条的剪伐方式,可显著提高芽条生长量和春叶产量,极显著提高秋叶产量,同时影响桑树生长发育.     

周宁县春种马铃薯新品种比较试验

马铃薯新品种中薯3号、紫花851、福克76和福克212在福建周宁试种。从品种的特征特性、晚疫病抗性及鲜薯产量综合分析,4个品种的鲜薯产量均比对照品种克新3号高,对晚疫病抗性均表现高抗或抗病,除了福克76裂薯较多外,其余3个品种的综合性状均表现较好。计划进一步加大对中薯3号、紫花851和福克212的引进力度,加快周宁县马铃薯老品种的更新换代步伐。同时继续引进新品种进行试种,增加农户对新品种的可选择性。     

剪叶对春油菜源库关系的影响

试验以春油菜青油-46为供试材料,在花期进行剪叶处理,研究源的减少对库器官的分化和形成的影响,研究表明:油菜花期去叶减少了源的面积,影响了油菜光合产物的积累,使油菜株高降低,茎秆变细,分枝减少,角粒数下降,千粒重增加,角果大小、单位角果皮面积的生产力(PPA)、单位角果皮面积负担的籽粒数(SNPA)下降,生物产量和经济产量降低,对分枝产量的影响大于主花序,且去叶越多下降越大,其中去短柄叶的影响大于长柄叶。     

杭州的四季茶会——Ⅰ.春天的敬老茶会

本文主要介绍了杭州四季茶会之春天的敬老茶会,包括茶会的缘起,历年茶会进行回眸,以及敬老茶会的特色。     

Organoclays for controlled release of the herbicide fenuron

Organoclays were assayed as matrices in which to associate herbicides, with the aim of decreasing product losses that could give rise to water contamination from agricultural activities. Fenuron was selected as model of a very mobile and highly water-soluble herbicide. Two different organoclays of high (A-HDT) and low (H-C18) reversible fenuron sorption were selected. Herbicide-organoclay complexes were prepared from the two organoclays and with two different fenuron contents (20 and 40 g AI kg-1) and two different mixing times, so as to form a series of weak and strong complexes. The release of fenuron from those complexes into water and water/soil suspensions gave values of T50 (time to release 50% of the fenuron content) ranging from 0.3 min to 2400 h. The total fenuron released in these closed systems ranged from 48 to 80% of the fenuron in the complex. The organoclay type (high or low sorptivity) had the greatest influence on fenuron release, followed by the strong or weak complex, suggesting that herbicide-organoclay interactions are the main factors controlling release. Soil column leaching experiments showed fenuron-organoclay complexes to be effective in reducing the peak herbicide concentration in the leachate to a half (6 microns) or a quarter (3 microns) of that obtained from the free technical compound (12 microns). Herbicide lost through leaching was reduced from 78% for the free technical fenuron to 50-30%, depending on the organoclay used as carrier and the strength of the complex. Bioassay with ryegrass showed that the weak fenuron/H-C18 complex (40 g AI kg-1) gave the same herbicidal activity as technical fenuron. The potential suitability of low-sorptive organoclays for conferring slow-release properties on the fenuron complex has been demonstrated.     

黄瓜腐霉菌苗期猝倒病致病机制研究

 本文明确了Pythium aphanidermatum主要靠生产以PG(多聚半乳糖醛酸酶)为主的一系列细胞壁降解酶的协调作用侵染黄瓜幼苗。植株胚轴细胞壁随苗龄增加,果胶物质增加最明显。病菌可在健胚轴及其细胞壁上培养产生果胶酶,其中细胞壁对PG的诱导作用比胚轴明显。随病菌致病力增强或病菌果胶酶浓度加大,胚轴的浸解和释放还原糖愈加明显。健株外渗物中虽也含有细胞壁降解酶,但比病菌的产生量少,活性低。病菌在寄生体内产生的细胞壁降解酶总酶活性,尤其是PG总酶活性与病菌致病力关系最为密切。这类细胞壁降解酶易受培养基成分和酸度的影响。经染色、显微及超微观察证实了该菌侵入黄瓜苗的机制是以酶解作用为主。     

Yield Structure of Winter Faba Beans Grown in Northern Germany in Dependence of Different Environments, Seed Rates, Sowing Rates and Genotypes

Two series of field trials were performed at three sites in Schleswig-Holstein between 1981 and 1988 to inquire into the yield structure of European winter types of Vicia faba L. and to compare their yield potential with that of spring types. Due to low winter survival, 6 winter types could be evaluated only in 4 environments in dependence of 1–3 sowing times (series α: seed rate 30/m²) and 1 winter type in 5 environments in dependence of 3 sowing times and 3 seed rates (series β: seed rate 15, 30, 45/m²). Seed yield of winter type averaged 410 g/m² (D.M.) surpassing spring types by about 14 %. Environments caused a considerable variation in yield (275–620 g/m²) and in each yield component of winter types, while sowing dates and seed rates hardly affected the components seeds/pod and seed weight, which displayed stable genotypic rank orders. Compensative forces among the components plants/m², tillers/plant and pods/tiller, were established. Plant densities of less than 10/m² in spring, generally led to seed yield below 350 g/m². Variation between 15–30 plants/m² due to environments, sowing times or seed rates were frequently not fully compensated by tillering of plants, but often variation of the thus formed yield potential was reduced by pod set of tillers resulting in 210–270 pods/m². The direction of correlations of pods/tillers with tillers/plant and plants/m² differed due to experimental conditions whereas negative correlations between pods/tiller and tillers/ m² were generally evident. Tillering was significantly influenced by the sowing time, though the increase because of early sowing was often covered by compensative effects of different plant densities. A genotypic capability to produce reproductive tillers was demonstrated using an approach which considered different plant densities and compensative forces. Neither a genotypic capability of tillers to set pods nor direct effects of environments or sowing time on pod set were established.     

使用AoBe处理不同生育期春小麦的增产效应

使用芳氧基乙酸万酯类化合物AoBe处理不同生育期春小麦,在低浓度条件下有促进幼苗生长、提高田间出苗率、刺激增产等生理作用,在高浓度条件下有抑制生长和致死作用。可见,AoBe具有植物生长调节剂的基本作用特性。AoBe刺激增产作用的适宜处理时期和浓度范围是:浸种和挑旗期为0.01ppm,分蘖期为0.1ppm,拔节期为1 ppm,抽穗期为100ppm左右。以0.01ppm浸种和0.1ppm在分蘖期喷施为最佳组合。1000ppm处理春小麦种子则表现为致死作用。