Factors in the Reduction in Grain Number in Winter Wheat by Early-Sowing in Yamaguchi

Abstract

Grain number per spike of wheat is lower in early sowing than in the conventional standard cultivation in Yamaguchi, Prefecture, Japan. Components of the grain number per spike in five cultivars were analyzed with respect to temperature during the spike development period throughout three growing seasons 2001/2002, 2002/2003 and 2003/2004 to find the cause of the problem of early sowing cultivation. The plants sown in early-October and late-November were called the early sown group and the standard group, respectively, in the following. Three of the five cultivars, Hokushin, Akitakko and Nanbukomugi, showed a strong winter habit, which requires very cold temperatures for spike differentiation. The other two cultivars, Iwainodaichi and Airakomugi, had a moderate winter habit. Grain number per spike and grain yield were decreased by early-sowing (compare with the standard group) in almost all cultivars throughout the three growing seasons. The three cultivars which had a strong winter habit had fewer spikelets per spike in the early-sown group than in the standard group. The other two cultivars which had a moderate winter habit had fewer grains per spikelet in the early-sown group. The higher the temperature during the spikelet formation phase, which is from flag leaf initiation to terminal spikelet initiation, the higher the number of spikelets per spike in the standard group. The spikelet number per spike in the early-sown group increased with the increase in productive tillers under fertile conditions. Such conditions also increased the grain number per spike.     

棉花体细胞无性系变异的研究进展

体细胞无性系变异是一种重要的细胞工程育种技术,其应用于棉花育种的前提是建立高效的组织培养诱导再生植株体系.本文简要综述了棉花离体诱导植株再生研究的现状,重点讨论了棉花体细胞无性系变异的表现、利用方法及机理,提出了当前研究存在的问题并对今后的研究进行了展望.     

2009年中国稻米市场分析及2010年展望

以翔实的资料对2009年中国稻米生产、消费、进出口、供求平衡、库存、价格走势、购销政策和国际稻米供求等情况进行了全面地分析,对影响2010年稻米市场价格走势的各种因素进行了深入研究,并在此基础上对2010年我国稻米市场价格走势进行了预测,结论是我国稻米价格仍呈上行趋势。     

汤原县水田除草方法演进

为科学地制定除草体系,在比较详尽地查实历史资料的基础上,将本县80a来的稻田除草方法划分为5个除草阶段,阐述了每个阶段的除草特点和除草效果,提出了今后稻田化学除草的发展方向。     

我国纤维用亚麻育种研究现状与发展

本文总结了我国纤维亚麻育种研究的进展和取得的成就;全面介绍了我国纤维亚麻育种研究的常用方法;并对纤维亚麻育种研究中存在的问题及今后的发展方向做了简要论述。     

我国纤维用亚麻育种研究现状与发展

本文总结了我国纤维亚麻育种研究的进展和取得的成就;全面介绍了我国纤维亚麻育种研究的常用方法;并对纤维亚麻育种研究中存在的问题及今后的发展方向做了简要论述.     

花生抗旱育种研究进展

概述了花生形态特征以及生理指标与花生抗旱育种之间的关系 ,介绍了花生抗旱育种的现状和最新分子生物学进展     

Advances in Variable Rate Technology Application in Potato in The Netherlands

Precision agriculture is a farming management concept based on observing, measuring and responding to inter- and intra-field variability in crops. In this paper, we focus on responding to intra-field variability in potato crops and analyse variable rate applications (VRAs). We made an overview of potential VRAs in potato crop management in The Netherlands. We identified 13 potential VRAs in potato, ranging from soil tillage to planting to crop care to selective harvest. We ranked them on availability of ‘proof of concept’ and on-farm test results. For five VRAs, we found test results allowing to make a cost-benefit assessment. These five VRAs were as follows: planting, soil herbicide weed control, N side dress, late blight control and haulm killing. They use one of two types of spatial data: soil maps or biomass index maps. Data on costs and savings of the VRAs showed that the investments in VRAs will pay off under practical conditions in The Netherlands. Savings on pesticide use and N-fertilizer use with the VRAs were on average about 25%, which benefits the environment too. We foresee a slow but gradual adoption of VRAs in potato production. More VRAs will become available given ongoing R&D. The perspectives of VRAs in potatoes are discussed.     

Changes in daily rainfall characteristics in major rice producing provinces in Laos

In order to find the changes in rainfall characteristics and to examine the flood damage to lowland rice, a statistical analysis was carried out on the 40-year daily rainfall record at four rainfall stations (Thangon, Paksane, Seno, and Pakse) in Laos. The rainfall record was divided into two periods of 20 years each. The results of this analysis revealed the trends in changes regarding the frequency and the timing of the heavy daily rainfall events at the four stations. In Paksane in particular, heavy daily rainfall events tended to occur in the latter half of the rainy season.     

Allelopathy in Agroecosystems in Spain

Summary

This paper reviews the effects of allelopathic interactions in agroecosystems in Spain on plant physiological activity and their ecological advantages. The phenological stage of growth of donor plants and the effective allelochemicals in the soil solution while studying the role of phenolic compounds were highlighting. Finally possible future prospects and conclusions regarding weed control by allelochemi-cals under integrated crop management strategies are discussed.     

三亚春季豇豆防虫网覆盖栽培小气候研究初报

研究了三亚春季防虫网覆盖栽培对豇豆生长小气候环境（温度、光照强度、湿度）的影响。结果表明：防虫网覆盖栽培能降低豇豆生长环境的温度，减弱光照强度，对空气湿度影响小。     

菠萝不同月份采收果实品质变化规律研究

以我国菠萝主栽品种‘巴厘’为试材,分析不同月份采收的菠萝果实Vc、可滴定酸、可溶性糖和可溶性固形物的变化,结果表明：不同月份成熟的菠萝果实Vc含量有差异,1～12月呈先降低后升高的趋势,11～4月较高,5～9月较低;可滴定酸含量与Vc含量变化趋势一致,11～3月较高,4～9月较低;不同月份成熟菠萝果实可溶性糖含量变化无明显规律,1、5、6、7、12月较高,其他月份较低;可溶性固形物含量表现出与Vc、可滴定酸含量变化相反的趋势,5～7月较高,其次为9、11,2、3月,可溶性固形物含量最低;各月份果实糖酸比情     

甜菜在海南冬种试验研究

连续４ 年在海南岛进行的甜菜冬季栽培试验结果证明,甜菜在具有热带气候的海南冬种是成功的,不仅长势好,病虫害也不严重。参试的３ 个甜菜品种根产量差异不显著,其中“丰抗３０９”品种块根产量４７．２５ｔ／ｈｍ２ ,含糖率１５．５２ 度。从９ 月３０ 日～１１ 月２０ 日６ 个播期处理的根产量差异显著,播期早、生育期长的产量高。试验认为,甜菜在海南冬种的最佳播期是９ 月３０ 日～１０ 月１０ 日,最佳收获期是３ 月２０ 日前后。因上茬作物晚收而不能及时播种时,采取育苗移栽,其产量不受影响     

2011年中国菠萝产业发展现状分析

在中国菠萝产业2011年发展现状的基础上，对广东、海南两大菠萝主产区进行详细分析，针对中国菠萝产业中存在的问题，提出加快产业发展的对策建议。     

茄子重要性状表型多样性及其在育种研究中的应用

调查分析29份茄子种质资源的8个数值型性状和10个非数值型性状指标。结果表明：29份材料的变异系数变化范围为0.090～0.568,其中叶长/叶宽的变异系数最小,萼片色变异系数最大;遗传多样性指数的变化范围为0.401～1.529,其中花瓣色遗传多样性指数值最小,茎色的遗传多样性指数最大;7个非数值型性状与抗青枯病的相关性分析结果显示,叶缘深度、叶脉色、茎色、萼片色、花瓣色、果形与田间青枯病病情存在一定的正相关性,嫩茎茸毛数量与田间青枯病发病情况呈负相关。本研究结果为茄子田间选育种研究提供可靠的依据。     

海城市水稻磷肥适用量研究

通过在海城市西四镇进行水稻施用磷肥的田间小区试验,研究该地区水稻施磷的增产效果和适宜用量,结果表明,在西四镇水稻产区施用磷肥各处理均有明显的增产效果,与对照相比增产64.5～142.3 kg/667 m2,增产率为11.5%～25.4%,经济效益明显。从水稻产量和肥料价格及经济效益等综合因素考虑,水稻的磷肥适宜用量为P2O5 7.75 kg/667 m2,最佳经济产量为699.4 kg/667 m2。     

我国干热区甘蔗抗旱植蔗主要问题研讨

我国干热蔗区是我国甘蔗糖业的重要生产基地,蔗区光热资源丰富,唯降水分布不均成为植蔗生产的主要限制因子;根据蔗区植蔗特点和甘蔗需水规律,苗期抗旱是干热蔗区抗旱植蔗的关键,保证较多的总苗数和足够的生长量是苗期抗旱植蔗需解决的关键技术难题,制定相应的苗期抗旱植蔗栽培技术措施是解决该难题的重要保障;该观点为我国干热蔗区植蔗生产、甘蔗引育种提供理论和技术支持。     

苎麻磷素吸收利用的基因型差异

对10个苎麻种质磷利用效率进行研究,以筛选出磷利用效率较高的种质.采用旱地试验、坡地试验、温室盆栽试验相结合,测定了不同种质的农艺性状、地上部干重和地上部磷含量,运用聚类分析方法,对10个种质磷利用效率进行分类.综合3个试验结果,可将10个品种分为3类：磷素吸收利用较强的是浏阳野麻、中苎1号、湘苎XB、湘苎X3、湘苎X1,磷素吸收利用能力中等的是湘苎X2、湘苎3号、多倍体1号,磷素吸收利用能力较差的是冷水江野麻、长沙野麻.     

云南山地橡胶树的养分空间变化特征

通过对云南西双版纳、普洱、红河、临沧植胶区的 16 个橡胶种植农场开割橡胶树，进行系统规模化的普查， 并评价其营养类型，以全面了解云南山地橡胶树的养分特征，为制定云南山地胶园专用的肥料大配方提供依据。研究 结果表明，不同植胶区橡胶树营养状况不尽相同，同一植胶区不同农场橡胶树营养状况亦有差异。云南植胶区橡胶树 叶片氮含量 24.62~47.46 g/kg，平均 34.69 g/kg；磷含量 1.57~4.92 g/kg，平均 2.45 g/kg；钾含量 5.67~26.91 g/kg，平均 13.57 g/kg；钙含量 4.03~28.55 g/kg，平均 11.05 g/kg；镁含量 1.41~6.98 g/kg，平均 3.63 g/kg。橡胶树叶片养分含量变 异系数为钙>镁>钾>磷>氮，依次为 26.14%、23.43%、19.04%、13.76%、9.04%。正常型、缺镁型、缺氮磷型、缺钾型 4 种营养类型的橡胶树占总普查橡胶树的 86.11%，为云南橡胶树的主要营养类型。     

我国枇杷种质资源与育种的研究进展

从枇杷的起源、系统分类和品种鉴定等方面综述了我国枇杷的种质资源研究现状;介绍了枇杷的引种、选种、育种等方面的研究进展。