宁南旱地连作春小麦产量动态与土壤干燥化效应模拟研究

为了解宁南旱区降水的变化特征,明确有利于土壤水分可持续利用的合理施肥水平,在数据库组建的基础上,应用WinEPIC模型定量模拟研究了宁南半干旱区固原和半干旱偏旱区海原1960～2000年期间不同肥力水平下连作春小麦的产量变化及其与深层土壤水分的关系.结果表明:(1)1960～2000年间宁南地区降水量呈波动性下降趋势;(2)宁南旱地连作春小麦产量以及麦田7 m土层逐月土壤有效含水量均随降水量变化呈现波动性降低趋势.在模拟初期1～3年土壤干燥化趋势十分强烈,此后长期在较低水平上随降水量的变化而波动;(3)随肥力水平的提高和春小麦连作年限的延长,宁南旱地连作春小麦田土壤干层逐年加深和加厚,在6～11年后形成了相对稳定的土壤干层.固原连作春小麦适宜的施肥量范围为N 60～90 kg/ha和P2O5 30～45 kg/ha,海原适宜的施肥范围为N 0～60 kg/ha和P2O5 0～30 kg/ha.     

烤烟种植适宜起垄高度与施肥方式研究

为了改善烟株大田生长状况,于2014年4月在云南省砚山县研究了起垄高度(20、30、40 cm)和施肥方式(单层条施、"101"施肥、环状穴施)对云烟87各生育期农艺性状和烤后烟叶(C3F)主要化学成分的影响,并测定了10、20 cm垄体土层的温度和含水率。结果表明:垄体温度有随垄高的增加而降低的趋势,这种变化随时间变化而逐渐减小;土壤含水率有随垄高的增加而降低的趋势,垄体土壤越深,含水率越低;起垄高度30 cm各处理的株高、最大叶长、最大叶宽高于其它起垄高度处理;而施肥方式以"101"施肥和环状穴施为优。烤后烟叶产量各处理差异不大,产值以30 cm×"101"施肥处理最高。     

拔节后补灌对不同穗型冬小麦耗水和籽粒产量的影响

为探究拔节期和开花期不同补灌方案对不同穗型冬小麦耗水特性、籽粒产量和水分利用效率的影响,于2017-2019年在山东省泰安市以大穗型品种山农23和中多穗型品种山农29为试验材料,以拔节后无灌水(T1)为对照,设置拔节期补灌目标为0~20 cm土层相对含水率达100%田间持水率(T2)、拔节期和开花期补灌目标为0~20 cm土层相对含水率达100%田间持水率(T3)和拔节期补灌目标为0~40 cm土层相对含水率达100%田间持水率(T4) 3种补灌方案。结果表明,拔节后不同补灌方案对大穗型和多穗型小麦品种影响基本一致。与T1处理相比,T4处理显著提高了0~100 cm土层土壤相对含水率,使60~100 cm土层土壤相对含水率在开花期仍保持较高水平;T3处理显著提高了拔节期0～60 cm和开花期0~40 cm土层土壤相对含水率。与T3处理相比,T4处理的拔节至开花阶段耗水量增加了28.9%,其中对上层土壤总供水的表观消耗量增加了66.4%;T4处理在开花至成熟阶段对深层土壤总供水的表观消耗量增加了68.0%,对上层土壤总供水的表观消耗量降低了37.4%。在开花至成熟期降水较多(121.2 mm)的年份,T4处理的开花至成熟阶段耗水量、开花后旗叶净光合速率和籽粒产量相对于T3处理均无显著变化,但总耗水量较高,水分利用效率显著降低;在开花至成熟期降水较少(45.2 mm)的年份,T4处理的开花至成熟期的阶段耗水量、开花后旗叶净光合速率、籽粒产量和水分利用效率较T3处理均显著降低。因此,在小麦全生育期降水量为111.6~220.2 mm、开花后降水量为45.2~121.2 mm的条件下,大穗型和中多穗型小麦品种均以在拔节期和开花期将0~20 cm土层补灌至100%田间持水率的补灌方案最优,可同时实现高产和高水分利用效率。     

膜下滴灌棉花不同盐分土壤水盐运移规律研究

 为了探讨膜下滴灌棉花土壤水盐运移规律,设置温室土柱栽培试验研究了不同盐分处理棉花各生育期土壤盐分、水分的运移规律。结果表明：在棉花整个生育期内,随着盐分含量的增加各土层的水分、盐分含量均表现增加的趋势,盐分高的处理土壤中水分含量也高,土壤水、盐含量最大值都出现在50～60 cm土层深度,40～60 cm土层为滴灌棉田盐分积聚区;不同盐分处理各土层含盐量差异均达显著水平,随着滴水淋洗,各盐分处理表层(0～10 cm)盐分含量差异不大,底层(50～60 cm)差异较大;盐分绝大部分集中于深层土壤,土层越深各处理土壤盐分含量差异越大。     

玉米秸秆还田对砂姜黑土水分动态及冬小麦水分利用效率的影响

为给冬小麦水分高效利用提供科学依据,根据土壤-植物-大气连续体(SPAC)原理,利用野外小型蒸渗仪,以不施肥为对照(CK),原位研究了配方施肥(PF)以及配方施肥+秸秆还田(PF+JG)处理对砂姜黑土水分动态和冬小麦水分利用效率的影响.结果表明,秸秆还田主要影响0～40 cm土层土壤剖面水分含量,而40～80 cm土层土壤水分含量基本保持稳定.在小麦出苗期和拔节期,PF+JG处理的0～40 cm土层土壤含水量较PF处理分别提高50.9％和34.6％.土壤水分最大有效库容在小麦全生育期呈单峰变化趋势,峰值在返青期;PF+JG处理的出苗期土壤水分最大有效库容较CK和PF处理增加了8.25％和20.82％,拔节期增加8.07％和10.95％,且均差异显著(P＜0.05).PF+JG处理的土壤水分入渗量分别是CK和PF处理的4.53和3.55倍;小麦耗水量较PF处理降低9.2％;小麦产量和水分利用效率分别比CK和PF处理增加124.1％、18.8％和144.0％、30.8％,且差异达显著水平(P＜0.05).说明秸秆还田对冬小麦产量和水分利用效率的提高作用与增加土壤水分有效库容、水分入渗量和减少总耗水量有关.     

秸秆还田量对旱地全膜覆土穴播春小麦水分利用及产量的影响

为了解半干旱区秸秆还田量对全膜覆土穴播春小麦水分利用和产量的影响,2018年在甘肃中部半干旱旱作区(35°35′N, 104°36′E)开展大田试验,以陇春35号为供试品种,设置1 500 kg·hm~(-2)秸秆还田(SRL)、3 000 kg·hm~(-2)秸秆还田(SRM)、4 500 kg·hm~(-2)秸秆还田(SRH)和无秸秆还田(CK)4个处理,测定和分析了不同处理下全膜覆土穴播春小麦不同生育时期0～300 cm土壤贮水量、0～300 cm土层阶段耗水量和WUE的特点。结果表明,与CK相比,不同量的秸秆还田均可提高春小麦播种到抽穗期0～300 cm土层土壤贮水量和拔节到灌浆期春小麦对0～300 cm土层的耗水量,降低拔节到成熟期冠层温度,显著增加春小麦叶片SPAD值、叶面积指数、生物量、产量和水分利用效率。SRM处理的产量较SRH和SRL处理分别增加4.0%和17.4%,WUE分别提高4.8%和16.0%。因此,在甘肃中东部半干旱旱作区,全膜覆土穴播春小麦的适宜秸秆还田量为3 000 kg·hm~(-2);秸秆还田能够改善春小麦生育前中期土壤墒情,有利于中后期水分利用,促进春小麦叶片光合物质生产,最终实现增产和水分高效利用。     

秸秆覆盖对黑土区大豆生长及产量构成因素的影响

为研究秸秆覆盖对黑土区土壤水热及大豆生长状况的影响，以垦丰16为试验材料，基于大田试验，分别设置秸秆表面覆盖(T1),0～10 cm土层秸秆还田覆盖(T2),10～20 cm土层秸秆还田覆盖(T3)和无秸秆覆盖(CK)4种处理。通过测定大豆生育期内的耕作层土壤温度及含水率，以及大豆株高、茎粗和叶面积等生长指标，对比分析不同秸秆覆盖处理对土壤水热、大豆生长及产量等性状的影响。结果表明：大豆生育期初T1处理0～10 cm土层含水率明显高于T2及T3处理；在10～20 cm差异逐渐缩小，20～30 cm土层差异变大；秸秆覆盖会影响播种初期的出苗率，而在播种10 d后T1处理的出苗情况最好；T2处理的大豆株高、茎粗、LAI及产量表现最佳。通过统计学分析不同秸秆覆盖之间的差异，秸秆覆盖具有一定的阻碍热量传递的作用，有利于土壤含水率的提高，对大豆生长状况、光合特性及产量产生影响，0～10 cm土层秸秆还田覆盖为最佳处理。     

不同叶龄期水稻秧苗对水分亏缺反应的探讨

水分亏缺对秧苗生长影响的研究甚多,但有关水稻秧苗本身对水分亏缺反应的研究报道尚不多见。本研究着重探讨了水稻不同叶龄期秧苗对水分亏缺的敏感程度、忍耐力及其生物学原因,为合理掌握旱秧育秧期水分管理提供理论依据。1 材料与方法选用杂交中籼汕优63和早熟晚粳武育粳2号为材料,在塑料顶蓬内的盆钵中进行。供试土壤为砂壤土,最大持水量为29.6%。1) 分期播种,培育不同叶龄的旱秧。从6月28日至7月23日,每隔3～6d播一期,共计6期。7月23日播最后一期后,各期秧苗全部停止水分补给。在此之前,适当给水,保持表土潮湿,以保证秧苗正常生长。2) 各播期分别设置浅土层和深土层两个处理:“浅土层”处理的土层厚度为5cm,5cm以下用塑料膜隔开,防止深层土壤水分上升及秧根下扎,用以探讨秧苗对水分亏缺的生物学反应。“深土层”处理的土层厚度为25cm,模仿旱地育秧的生长环境,用以探讨秧苗对水分亏缺的农学反应。     

灌水对不同小麦品种耗水特性和土壤硝态氮运移的影响

为了解灌水对不同小麦品种耗水特性和土壤硝态氮运移的影响,在大田条件下,以济麦20和泰山22为材料,设置4种水分处理[W0处理（全生育期不灌水）、W1处理（灌底墒水＋拔节水）、W2处理（灌底墒水＋拔节水＋开花水）、W3（灌底墒水＋拔节水＋开花水＋灌浆水）],每次灌水量60mm,分析了不同灌水处理下小麦0～200cm土层土壤含水量、土壤水消耗量、土壤硝态氮运移及籽粒产量的差异。结果表明,（1）依据土壤含水量受灌水影响的程度和变异系数,将0～200cm土壤分为3个层次：活跃层（0～60cm）、次活跃层（60～140cm）和相对稳定层（140～200cm）。（2）两品种W1处理的冬前、开花和成熟期0～60cm土层土壤硝态氮含量低于W0处理;冬前期60～140cm土层高于W0处理,140～200cm土层与W0处理无显著差异;开花期60～140cm和140～200cm土层高于W0处理;成熟期0～60cm土层高于W2、W3处理,60～140cm和140～200cm土层低于W3处理。拔节期济麦20W1处理60～140cm和140～200cm土层土壤硝态氮含量高于W0处理,泰山22的低于W0处理。（3）济麦20各处理0～200cm土层土壤水消耗量均高于泰山22。济麦20W1处理0～60cm和60～140cm土层土壤水消耗量高于W2处理,籽粒产量、水分利用效率高于W2、W3处理;泰山22W2处理0～60cm土层的土壤水消耗量与W1处理无显著差异,60～140cm和140～200cm土层的土壤水消耗量低于W1处理,水分利用效率与W1处理无显著差异,但高于W3处理,籽粒产量高于W1、W3处理。济麦20和泰山22分别以底墒水、拔节水各灌60mm和底墒水、拔节水、开花水各灌60mm为节水、高产、氮素淋溶量低的最佳灌水模式。     

春小麦钾素吸收、积累与分配规律的研究

为了给高产栽培提供理论上的支持，在不同密度和施肥条件下，对春小麦钾素的吸收、积累动态进行系统的研究。结果表明，春小麦全生育期内植株体内含钾量呈逐渐下降趋势，在苗期至分蘖末期最高，到完熟期降至一生中最低值。春小麦一生中吸钾高峰在分蘖末期。且因不同密度、施肥处理表现一定差异。高密度、高钾肥处理吸收钾素相对较多，而氮磷钾平衡配施处理对钾素的吸收量始终维持在较高水平，且经济产量最高。春小麦一生中钾素的积累量与生育进程间的关系符合二次曲线变化。     

Effects of seeding rate and cultivar on tomato spotted wilt of peanut

Tomato spotted wilt, caused by thrips-vectored Tomato spotted wilt virus (TSWV), is a very serious problem in peanut (Arachis hypogaea L.) production in the southeastern U.S. Establishment of within row plant densities of 13 or more plants/m of row of moderately resistant cultivars is recommended as part of an integrated management system for minimizing losses to spotted wilt. To achieve that plant density, growers often plant 19 or more seed/m of row. Seed costs represent a major expense for peanut producers. Reducing costs by using lower seeding rates would be desirable if it could be done without increasing risk of losses to tomato spotted wilt. Field experiments were conducted in Tifton, Georgia in 2008 and 2009 to determine whether new cultivars with improved field resistance to TSWV can allow use of lower seeding rates without increasing risk of losses to tomato spotted wilt. In each year, peanut cultivars, Georgia Green, Georgia-06G, Florida-07, and Tifguard were combined factorially with four seeding rates, 9.8, 13.1, 16.4, and 19.7 seed/m of row. Across the two years, final incidence of tomato spotted wilt and standardized area under the disease progress curve for tomato spotted wilt epidemics decreased linearly with increasing seeding rate for all cultivars. Across the two years, final incidence of tomato spotted wilt at 9.8 seed/m of row seeding rate was 55% for Georgia Green and 17% for the mean of the other three cultivars. For Georgia Green, incidence of tomato spotted wilt decreased 1.9% with each seed/m increase in seeding rate, whereas the incremental decrease was 0.8% for the mean of the other three cultivars. These results indicate that levels of field resistance to TSWV in several new cultivars are adequate to allow use of lower seeding rates than with the moderately resistant cultivar Georgia Green without increasing the risk of losses to spotted wilt.     

Effect of non-aflatoxigenic strains of Aspergillus flavus on aflatoxin contamination of pre-harvest peanuts in fields in China

Aflatoxin contamination of peanuts is one of the most concerns in peanut production in China. Applying non-aflatoxigenic Aspergillus flavus strains, based on competitive exclusion, has been proved to be a promising strategy to reduce aflatoxin contamination in pre-harvest peanuts. Two non-aflatoxigenic A. flavus strains collected in China, which have been proved effectively reducing aflatoxin in the laboratory, were mixed with high aflatoxin producer to the soil in peanut growing season. The two non-aflatoxigenic strains significantly (P ​< ​0.05) reduced aflatoxin contamination in peanut kernels under both normal and drought stresses in two fields. Compared to control, the total aflatoxin (sum of aflatoxin B₁ and B₂) was reduced 26.7–99.12% in field 1, and 84.96–99.33% in field 2. The aflatoxin was reduced 84.96–99.33% under drought stress in two fields. The present study indicated the non-aflatoxigenic A. flavus strains could be potential biocontrol agents for reducing aflatoxin contamination under field condition.     

The effect of combined application of the entomopathogenic fungus Metarhizium anisopliae and the release of predatory mite Phytoseiulus longipes for the control of the spider mite Tetranychus evansi on tomato

The entomopathogenic fungus Metarhizium anisopliae (Ma) and the predatory mite Phytoseiulus longipes (Pl) are both potential biocontrol agents of the tomato spider mite Tetranychus evansi. The combination of the two agents may enhance biological control of T. evansi if there is no antagonistic effect. Here, we evaluated the effect of combining the application of Ma and Pl in the control of T. evansi under screenhouse and field conditions on tomato crops. The acaricide abamectin was included as a control. Spray applications of Ma and abamectin, and release of Pl in the screenhouse significantly reduced mite population density among motile (P < 0.0001) and egg stages (P < 0.0001) of T. evansi as compared to the control. There was also significant reduction in mite population density in the field but only with spray applications of Ma and abamectin, and Ma + Pl treatments among motile (P < 0.0001) and egg stages (P < 0.0001). In the screenhouse experiment, leaf damage was significantly lower in all the treatments than in the control. In the field, leaf damage was significantly higher in the control and Pl alone treatments than in the other treatments. The combination of both Ma and Pl resulted in a reduction of T. evansi numbers in the screenhouse and field, but did not consistently differ significantly from Ma alone. Based on these results, we conclude that there is no benefit of combining M. anisopliae and P. longipes for the control of T. evansi in tomato crops.     

SSR标记与田间种植鉴定玉米品种纯度的比较

从行业标准中筛选出8对适用于玉米品种纯度鉴定的引物组合,能区分90％以上的审定品种.96％的审定品种在8个引物组合中有4个以上的杂合位点,具有较高的杂合率和品种区分能力.38份来自全国种子市场的样品同时进行田间种植和SSR纯度鉴定,8对SSR引物组合检测出自交苗平均值为0.6％,异型株为1.8％,纯度为97.7％;田间...     

Effects of new field resistant cultivars and in-furrow applications of phorate insecticide on tomato spotted wilt of peanut

Field experiments were conducted at Tifton, Georgia from 2008 to 2014 to determine the effects of new peanut (Arachis hypogaea) cultivars and in-furrow applications of phorate insecticide on severity of tomato spotted wilt (TSW) caused by Tomato spotted wilt virus. Several cultivars, including Florida-07, Georgia-06G, Georgia-07W, Georgia Greener, and Tifguard, had final incidence of TSW that were less than that of Georgia Green. In-furrow applications of phorate insecticide reduced incidence of TSW in Georgia Green in three experiments in which that cultivar was included. In-furrow application of phorate insecticide reduced incidence of TSW in most cases where incidence in nontreated plots was 10% or higher. Cultivars Georganic, and Georgia-10T, had final incidence of TSW that was lower than that of Georgia-06G, or Florida-07 within nontreated plots across 2011–2012. Georgia-10T and Georgia-12Y had final incidence that was lower than that of Georgia-06G, Georgia-07W, Georgia-09B and Georgia Greener across insecticide treatments in 2013. In-furrow application of phorate increased yields across cultivars in 2008–2009, and increased yield of Georgia-09B in 2010. In most other cases, phorate had no significant effect on yield. With higher levels of field resistance in most of these cultivars, especially those such as Georgia-12Y, benefits from use of phorate insecticide for TSW suppression were small, and typically did not result in yield increase. Based on these results, several of these cultivars should allow greater flexibility for insecticide choice for thrips management without increasing the risk of losses to TSW.     

Properties of field-sprouted sorghum and its performance in ethanol production

The objective of this research was to investigate physicochemical and biochemical characteristics of field-sprouted grain sorghum and its fermentation performance in ethanol production. Five field-sprouted grain sorghum varieties, which received abnormally high rainfall during harvest, were used in this study. Enzyme activities, microstructure, flour pasting properties, kernel hardness, kernel weight, kernel size, flour size and particle distribution of field-sprouted grain sorghum were analyzed. The effect of germination (i.e., sprouting) on conversion of grain sorghum to ethanol was determined by using a laboratory dry-grind ethanol fermentation procedure. Sprouted sorghum had increased α-amylase activity; degraded starch granules and endosperm cell walls; decreased kernel hardness, kernel weight, kernel size, and particle size; and decreased pasting temperature and peak and final viscosities compared with non-sprouted grain sorghum. The major finding is that the time required for sprouted sorghum to complete fermentation was only about half that of non-sprouted sorghum. Also, ethanol yield from sprouted sorghum was higher (416–423 L/ton) than that from non-sprouted sorghum (409 L/ton) on a 14% moisture basis.     

枯草芽孢杆菌防治草莓白粉病的田间试验

草莓白粉病是琼海草莓生产中的常发性主要病害,严重影响草莓的生产。琼海草莓种植期间低温、高湿气候情况频发,有利于草莓白粉病的发生。通过不同配方组合发现：枯草芽孢杆菌按4 050 g/hm2用量单独使用,预防草莓白粉病防效达92.09%,发病后混合化学药剂露娜森做治疗,具有防效快、持效期长等优点。     

莜麦田间杂草调查及除草剂的筛选

[目的]筛选适宜五寨县莜麦田的除草剂。[方法]以二甲四氯、苯磺隆和2,4-D丁酯为供试药剂,通过调查五寨县莜麦田杂草种类和数量,研究3种除草剂的除草效果及对莜麦产量的影响。[结果]五寨县莜麦田杂草主要有狗尾草、稗草、碱草、茅草、禾草、芒草、雀麦草等1年生禾本科杂草,灰菜、苋菜、胡舌芽等1年生藜科杂草,以及菊科杂草甜苣、苦苣和苍耳、田旋花、酸地柳等;使用传统的人工锄草灭草和增产效果最好;化学除草剂2,4-D丁酯稀释1500～2000倍除草效果较好,分别较喷施二甲四氯、苯磺隆增产4.62%和3.82%。[结论]采用先使用化学除草剂,再人工锄草,或后期拔大草模式除草效果最好。     

水稻稻瘟病田间抗性的遗传与选种

 1982～1985年在辽宁省丹东市前阳水稻试验站对用三个田间抗性亲本配成的六个组合(银河/蒙古稻、蒙古稻/银河、誉锦/蒙古稻、蒙古稻/黎明、银河/水原300粒和银河/京越1号)的F_1、F+2和F_3代的表现做了调查。试验结果表明,单位叶面积上的侵染点数和感病病斑数、病斑在单位时间内的扩展速度、发病叶面积百分率(DLA)以及穗颈瘟百分率在F_2和F_3的分布都为连续正态或偏态分布,变异位于双亲之间,很少有超亲现象,证明这种田间抗性为多基因控制的数量性状,广义遗传力(平均)和狭义遗传力(平均)分别以单位叶面积上的感病病斑数(h_B~2=79.5%)和穗颈瘟百分率(h_N~2=65.3%)最高。各性状的亲子相关都达显著水平。文中提出,育种中田间抗性的选择,低世代(2—4代)以DLA为指标,高世代(5代以后)以感病病斑数和病斑扩展速度为指标。对叶瘟和穗瘟抗性的选择应分别进行。     

The heterogeneous distribution of α-amylase and endoxylanase activity over a population of preharvest sprouted wheat kernels and their localization in individual kernels

To develop targeted approaches to improve the quality of preharvest sprouted (PHS) wheat as a raw material for food manufacturing, knowledge on the nature and distribution of hydrolytic enzymes in PHS wheat is crucial. Results of the present study indicate that α-amylase and endoxylanase activities are heterogeneously distributed among a population of PHS kernel. Within individual severely sprouted kernels, the enzyme activities are heterogeneously distributed throughout the different tissues. α-Amylase activity, almost exclusively of endogenous nature, is mainly detected in the germ region and to a lesser extent in the aleurone layer. Endoxylanase activity is predominantly of microbial origin and located on the kernel surface. In spite of this, light and epifluorescence microscopy show decreased kernel integrity and cell wall breakdown in the crushed cells layer, the endosperm, and the aleurone layer in a selection of kernels upon preharvest sprouting. This knowledge offers opportunities for the development of treatments to reduce the enzyme load in PHS wheat at postharvest level to improve its flour quality.