南疆棉花化学打顶剂应用研究

为了验证棉花化学打顶剂代替棉花人工打顶及抑制棉花顶端生长的作用,形成一套棉花化学打顶整体实施技术,用于降低劳动强度和生产成本。2014年利用由国家棉花产业技术体系栽培研究室棉花化学调控团队提供化学打顶剂(M剂和Y剂)在新疆图木舒克开展棉花打顶试验。结果表明:化学打顶剂可以起到有效控棉株生长的作用,且比人工打顶更能改善棉田上部群体结构,提高棉田通风透光性,但对衣分、绒长、单铃重等影响不大,对产量促进作用也不大,株高低于不打顶处理,而高于人工打顶处理;不孕籽率较人工打顶和不打顶处理偏少。     

新疆棉区棉花化学打顶剂的筛选研究

为了进一步明确品种和打顶剂种类对化学打顶效果的影响,并筛选出新疆棉区适宜的化学打顶剂,于2017年在胡杨河试验站采用裂区设计系统研究了品种和打顶处理（5种化学打顶剂、不打顶和人工打顶）对棉花株型、产量性状、早熟性和纤维品质的影响。结果表明,品种间株型、产量、早熟性和纤维品质差异显著;不同化学打顶剂和不打顶处理棉花株高、果枝数较人工打顶增加,但籽棉产量、早熟性和纤维品质处理间差异不显著;打顶处理以及品种和打顶处理的互作效应显著影响籽棉产量。在两个品种中,“金棉”和氟节胺处理籽棉产量均与人工相当或高于人工打顶,而其他化学打顶剂及不打顶处理的籽棉产量品种间趋势差异较大。“金棉”和氟节胺对品种要求较低,可在新疆棉区推广应用。     

化学打顶剂在新疆棉花生产中的研究与应用

化学打顶是利用植物生长调节剂强制延缓或抑制棉花顶尖的生长。从而达到调节营养生长与生殖生长的目的。化学打顶剂作为抑制棉花顶尖和群尖的一种化学制剂,以其操作便捷、可在一定程度上代替人工打顶、降低用工成本、提高劳动生产率而受到新疆地方和兵团植棉团场的重视,并展现出了很好的应用前景。本文综述了目前棉花化学打顶剂的试验研究和大田示范推广应用概况,并对现阶段在新疆使用面积较大的几种化学打顶剂产品施用方法进行了介绍,同时对化学打顶剂在新疆的应用前景进行了展望。     

棉花后期喷化学药剂打顶对其生长及产量影响

为了验证赣北棉区棉花后期化学药剂打顶对其顶部生长发育及产量的影响,完善棉花化学打顶技术在江西的本土化应用,于2014年棉花打顶期,设置了不打顶、人工打顶、喷施不同浓度的化学打顶剂处理,调查各处理喷药后的棉花生长发育情况及产量性状。结果表明:一是与不打顶相比,棉花后期喷施适宜浓度的化学打顶剂,可以极显著地降低棉花的株高、抑制棉株上部果枝的伸长,控制棉株顶部果枝及主茎节间的伸长,减少无效果节数,塑造合理的株型,起到了类似或优于人工打顶的效果;二是在棉花常规打顶适期喷施化学打顶M剂1125 ml/hm2加Y剂750 ml/hm2,其霜前籽棉产量和铃重显著高于人工打顶处理,略高于不打顶处理。     

新疆阿克苏地区陆地棉化学封顶配套栽培技术

化学封顶替代人工打顶可降低劳动强度、提高作业效率，有助于实现棉花生产全程机械化。介绍了陆地棉化学封顶技术及配套的水肥运筹、整枝塑形、化学调控技术，以期为化学封顶技术在新疆阿克苏地区大面积推广应用提供技术支持。     

新疆棉花化学打顶后期脱叶技术规程

化学打顶与化学催熟脱叶相结合,可替代人工打顶,降低籽棉的含杂率,同时可以提高劳动效率和降低劳动强度,从而达到棉花提质、增产、增效的目的。本文总结了新疆棉花化学打顶后期脱叶技术,包括：适用范围、脱叶剂剂型与配方、喷药时间与配药方法及作业机械的基本要求、田间作业、作业后的清洗与保养、安全要求等关键技术。     

不同化学打顶剂对新疆棉花群体质量的影响

2020年以新陆早74号为研究对象,以人工打顶为对照,研究了甲哌钅翁和氟节胺不同剂量处理对棉花群体质量指标的影响,为棉花化学打顶技术的推广提供科学依据。结果表明：使用2种化学打顶剂后棉花叶面积指数、群体光吸收率、群体光合速率都随剂量的增加而下降,中剂量处理干物质积累量和蕾铃分配比最佳,同时中剂量处理的株高、单株果枝数、皮棉产量均高于对照处理。本研究初步明确了2种化学打顶剂不同剂量处理对棉花群体质量指标的影响,并证明了化学打顶替代人工打顶的可行性。     

棉花化学打顶对机采棉脱叶催熟效果的影响

为了探求棉花化学打顶是否影响化学脱叶催熟剂使用效果,2014―2015年选择2种化学打顶剂（氟节胺复配剂、缩节胺复配剂）,以人工打顶方式为对照,研究不同打顶方式对机采棉脱叶催熟效果的影响。试验结果表明,化学打顶处理棉花在吐絮期喷施脱叶催熟剂8 d后,脱叶率和吐絮率都显著高于人工打顶棉花,2年平均高出约4.6和2.4百分点,挂枝叶（离层形成且脱落但被挂在茎秆、果枝上的叶片）率较人工打顶处理棉花低2.2百分点;喷施脱叶催熟剂16 d后,脱叶率、吐絮率相对人工打顶处理2年分别高1.9、6.4百分点,挂枝叶率相比人工打顶处理棉花少1.5百分点。化学打顶棉花在喷施脱叶催熟剂后8 d,2年脱叶率均在90%以上,喷施脱叶催熟剂后16 d,吐絮率均超过90%;与化学打顶棉花相比,人工打顶棉花脱叶率和吐絮率达到90%所需时间多7～8 d。综上,化学打顶处理可提高叶片脱落率,降低挂枝叶率,提升脱叶质量,使棉铃吐絮时间集中。     

化学打顶对东疆棉花生长发育主要性状的影响

以陆地棉品系大铃148为供试材料,以主要成分为氟节胺的“禾田福可”为打顶剂,研究了化学打顶和人工打顶对棉花株高、果枝节数、棉铃空间分布、铃重等主要农艺和产量性状的影响。结果表明：化学打顶能有效抑制棉花顶尖生长,起到类似人工打顶的效果。和常规人工打顶相比,化学打顶棉花株高和主茎节间数差异达到极显著水平;下部和中部结铃数差异显著,产量差异不显著。     

新型化学打顶剂对棉花生长发育的影响初探

为了在豫东推行棉花化学打顶,以配合轻简化栽培管理,顺应棉花全程机械化发展要求,对新型化学打顶剂进行田间试验。结果表明该新型化学打顶剂可以有效降低棉花的株高、减少果枝数,有效抑制棉花顶尖生长,有利于提高棉花产量和衣分,基本可以起到类似人工打顶的作用。     

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.     

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.     

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。     

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。     

Diurnal changes in net photosynthetic rate in potato in two environments

Summary Diurnal changes in net photosynthetic rate were measured in a furrow-irrigated potato crop and in a riverbed crop where the water table was always maintained at 20–28 cm from the soil surface. In the irrigated crop, the photosynthetic rate during mid-afternoon was about half the peak rate observed at noon. This reduction was accompanied by a near tripling of stomatal resistance, a 45% reduction in transpiration, and a 5-fold increase in the difference between leaf and air temperatures. No such changes were observed in the riverbed crop where the photosynthetic rate remained nearly constant at about 0.9 mg m⁻² s⁻¹ between 9 a.m. and 4 p.m. Tuber yield in the riverbed crop was about 30% higher than in the irrigated crop.     

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.     

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.     

Sugar and dry matter changes in potatoes overwintered in soil in Greece

Summary Potatoes were left in the soil from December, when the vines died, until February (cvs Claustar and Sebago) or April (cv. Spunta) in a location of central Greece with light, well drained soils and a mild climate. Tubers were analysed every two months for dry matter and sugar content and usually the dry matter content did not change significantly from December to February or April. The reducing sugars increased from December to February in tubers of all cultivars and significantly decreased in cv. Spunta from February to April.     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

中国马铃薯单倍体诱导进展

马铃薯产量、品质、加工等方面都较其他作物有更大的提升空间,但由于四倍体马铃薯存在遗传基础狭窄且复杂、难以创新等诸多问题阻碍了相关研究的深入开展。利用马铃薯单倍体或双单倍体植株有望解决上述诸多难题。马铃薯单倍体具有加速育种过程、提高选择效率等优点。马铃薯单倍体的获得包括花药培养、花粉培养、孤雌生殖、子房培养。其中,花药培养因更易取材,并且得到胚性细胞团、愈伤组织或胚状体的几率更大等优点而研究最为广泛。获得单倍体植株的成功率与试验材料的基因型、培养条件、培养基添加物等诸多因素相关。根据不同的诱导方法简要阐述了中国马铃薯单倍体研究的历史及进展。