种植密度对3个紧凑型玉米品种抗倒伏性和产量的影响

以郑单958、先玉335、浚单20为材料,研究不同密度下3个紧凑型玉米品种抗倒伏性和产量的影响。结果表明,随着密度增加,3个玉米品种的倒伏率逐渐升高,平均倒伏率浚单20先玉335郑单958。随着密度增加,玉米株高、穗位高、穗高系数均逐渐升高,玉米倒伏率与穗位高呈极显著正相关,与株高和穗高系数相关性不显著。玉米茎秆穿刺强度随着节位的上升呈下降趋势,随着密度增加,茎秆穿刺强度逐渐降低,不同密度下每一节的穿刺强度均为先玉335郑单958浚单20,不同节间的穿刺强度表现为第二节第三节第四节第五节第六节。随着密度增加,玉米穗行数、穗粒数和百粒重均呈降低趋势,行粒数在不同品种间表现不同,郑单958和先玉335均呈下降趋势,浚单20则先升后降。随着密度增加,郑单958、先玉335的产量表现为先升高后降低的趋势,在7.5万株/hm2时达最高值,分别为13 141.5、14 324.2 kg/hm~2,浚单20呈下降趋势。因此,与郑单958和浚单20相比,先玉335在冀西北地区种植抗倒伏且获得高产。     

不同抗倒能力玉米品种物质生产与分配及产量性状研究

2005～2006年以4个不同耐密性品种为材料,研究玉米不同抗倒能力对光合物质生产及其产量的影响.结果表明,当稀植(52 500株/hm2)条件下,大穗品种京科518和京科519的丰产优势明显,叶面积指数、群体光合势、单株干重和群体干物质积累量均较高,其产量显著高于耐密品种登海3719;当群体密度大于75 000株/hm2以上时,发生倒伏,两品种绿叶面积和光合性能下降,群体干物质积累减少,有效收获穗数显著降低,产量明显下降.从玉米抽雄前到生理成熟期,根系干重所占比例越高,植株抗倒伏能力越强;玉米抽雄前单株干重和根干重所占比例与倒伏率呈显著负相关,相关系数分别达-0.5405*和-0.5302*.田间倒伏对产量有较大影响,选用在吐丝前根系发达、干物质积累多的玉米品种抗倒能力强,是实现在大群体条件下创高产的保障.     

Effect of planting density on lodging-related morphology,lodging rate,and yield of tartary buckwheat (Fagopyrum tataricum)

Increase of planting density has been widely used to increase grain yield in crops. However, it may lead to higher risk of lodging hence causing significant yield loss of the crop. To investigate the effects of planting density on lodging-related morphology, lodging rate (LR), and yield of tartary buckwheat, an experiment was carried out with a split-plot randomized block design at the experimental farm of Chengdu University (Sichuan, China) in the 2012 and 2013 growing seasons. Results showed that plant density significantly affected characteristics of stem and root. In each season, with the increasing of planting density, light transmittance, main root length, number of first lateral root, root volume, internode number, and first internode diameter decreased, the plant height, first internode length, abortion rate and LR increased. Increasing density caused decreased grains number per plant, the dry matter weight and yield displayed an acceleration first and then deceleration. The correlation analysis indicated that the internode number, first internode diameter, number of first lateral roots, and root volume were significantly negatively correlated with LR, but positively correlated with stem breaking strength and lodging resistance index. The LR was significantly positively correlated with plant height and first internode length. In both years, the D2 (9 × 10⁵ plant ha^?1) and D3 (12 × 10⁵ plant ha^?1) yielded more grains than in other treatments, and the effects of density on two cultivars showed the same trend. The results suggested that planting density could alter lodging-related traits, lodging resistance, and yield of tartary buckwheat.     

宽幅条播和种植密度对燕麦抗倒伏性及产量的影响

为明确宽幅条播对燕麦抗倒伏性和产量的调节作用及其适宜种植密度,于2019-2020年,通过裂区试验,设置2种播种方式（宽幅条播和常规条播）和三个种植密度水平［300×10株·hm^-2（D1）、450×10株·hm^-2（D2）、600×10株·hm^-2（D3）］,分析了播种方式与种植密度对燕麦植株抗倒伏性和籽粒产量的影响。结果表明,同一种植密度下,宽幅条播的燕麦茎秆机械强度、茎粗、壁厚均显著高于常规条播。在籽粒灌浆期,与常规条播相比,宽幅条播的燕麦基部第二节间机械强度在 D1、D2、D3下分别提高9.3%、11.6%和17.0%,茎粗分别增加7.3%、7.6%和7.3%,株高分别降低2.3%、1.9%和3.0%,重心高度分别下降 6.5%、7.8%和 6.0%。相比于常规条播,燕麦宽幅条播主要通过增加穗数来增产。在D1、D2、D3下,宽幅条播的两年平均产量较常规条播分别增加了8.6%、9.3%和14.5%。随着种植密度的增加,两种播种方式下燕麦茎秆机械强度、茎粗、壁厚均呈减小趋势,株高、重心高度、节间长均呈增加趋势,但宽幅条播的各指标变化幅度均小于常规条播。因此,生产中采用宽幅条播可显著提高燕麦茎秆抗倒伏能力和籽粒产量,适当增加种植密度,可实现燕麦抗倒性与产量协同提高;本试验条件下,宽幅条播燕麦达到最高产的密度为600×10 株·hm^-2。     

宽幅条播和种植密度对燕麦茎秆抗倒伏性能的影响

为明确宽幅条播和种植密度对燕麦茎秆抗倒伏性能的调节作用,于2019—2020年在内蒙古乌兰察布市农牧业科学研究院试验基地,以燕麦品种蒙农大燕1号为试验材料,设置宽幅条播和常规条播两种播种方式及300万株·hm^-2、450万株·hm^-2、600万株·hm^-23个种植密度,分析不同播种方式和种植密度下燕麦茎秆木质素、纤维素、半纤维素和钾含量及抗倒伏指数和倒伏率的差异。结果表明,随着种植密度的增大,燕麦倒伏率及倒伏等级均呈增加趋势,茎秆木质素、纤维素、半纤维素、钾含量及抗倒伏指数均呈下降趋势。在同一种植密度下宽幅条播燕麦的茎秆木质素、纤维素、半纤维素、钾含量及抗倒伏指数均高于常规条播,其中纤维素含量较常规条播增加了5.7%～16.3%,且在高密度下增幅最大;半纤维素、木质素和钾含量及抗倒伏指数分别增加10.9%～20.3%、13.6%～23.3%、1.6%～25.5%和12.7%～56.5%。宽幅条播有利于燕麦产量构成因素协同增加,尤其是穗数增加,进而起到增产作用,在高密度下效果更显著。由此可见,宽幅条播可有效缓解群体密度增加...     

冀东地区种植密度对小麦京冬8号抗倒伏能力和产量的影响

为明确冀东地区种植密度对冬小麦抗倒伏能力和产量的影响,于2011-2013年度以当地推广的冬小麦品种京冬8号为材料,设每公顷375万、525万、675万和825万株4个种植密度处理,分析了不同密度下小麦茎秆质量、抗倒伏指数和产量的差异.结果表明,密度增大使小麦基部第1节间增长,增加了基部节间长在茎长中所占的比例、株高和重心高度,导致茎秆变细,茎秆机械强度和抗倒伏指数降低.当密度达到每公顷675万株时,小麦出现倒伏,密度再增加,倒伏时间提前,倒伏程度增大.群体干物质积累量在生育前期随密度增加而增加,但大密度导致植株分蘖衰亡较多,降低生育后期干物质生产能力,至成熟时以每公顷525万株的干物质积累量和花前营养器官贮存干物质向籽粒的运转量最多.虽然每公顷675万株的有效穗数最多,但由于倒伏严重,其千粒重最轻,每公顷825万株的有效穗数和穗粒数均较少,因此这两个高密度处理的产量均较低.综合来看,在冀东地区,适期播种条件下,小麦京冬8号以种植密度为每公顷375万～525万株为宜,此密度下茎秆质量较高,抗倒伏能力较强,产量较高.     

覆膜滴灌条件下灌溉量和种植密度对玉米茎秆抗倒能力的影响

设置两年灌溉量和种植密度互作试验,研究不同密度下,随灌溉量增加,玉米茎秆抗折断力、植株高度、基部节间形态及机械强度等的变化趋势,明确覆膜滴灌条件下灌溉量对密植玉米茎秆抗倒伏能力的影响.结果表明,随密度增加,茎秆抗倒能力呈下降趋势.不同密度下,滴灌量变化对茎秆抗倒能力的影响不完全一致.密植条件下,适当增加灌量(480～5...     

不同种植密度下玉米基因型产量及根拔拉力的关系

以19个测交种为供试材料,在两种种植密度下评价其根拔拉力及产量构成。结果表明,19个测交种在不同密度下的根拔拉力具有显著基因型差异。依据各自对两个密度的反应程度,共划分为双高抗倒型、高密抗倒型、中密抗倒型、双低抗倒型4种类型,结合产量构成共筛选出4个高产抗根倒伏的候选基因型。相关分析表明,玉米根系垂直拉力抗性与其秸秆产量显著相关,且相关性随着密度增加而提高,而与子粒产量无关。     

不同种植密度下玉米品种倒伏与产量的相关分析

研究种植密度对两个玉米品种郑单958和先玉335抗倒性和产量的影响。试验结果表明,随着密度的增加,倒伏率逐渐增高,先玉335的平均倒伏率大于郑单958;玉米株高、穗位高、穗高系数均随着密度的增加逐渐升高,且与倒伏率呈显著或极显著正相关;随着密度的增加,两个玉米品种的产量表现先上升后下降的趋势,在7.5万株/hm^2时产量达到最高。倒伏率与产量相关分析表明,郑单958和先玉335的倒伏率与产量均呈显著负相关。     

密度和施氮量对强筋小麦藁优2018产量和抗倒性的影响

为明确减量播种和减施氮肥对强筋小麦品种藁优2018茎秆质量和抗倒性的影响,采用双因素裂区试验,研究了种植密度(D210,210万株·hm-2;D330,330万株·hm-2;D450,450万株·hm-2)和施氮量(N0,0kg·hm-2;N120,120kg·hm-2;N240,240kg·hm-2)对小麦倒伏高发期茎秆形态的影响,以及抗倒伏指数与茎秆形态指标的相关性。结果表明,在籽粒形成期和蜡熟期,密度由D210增加至D330,小麦茎秆重心高度显著增加,基部节间充实度、秆壁厚度、茎秆机械强度和抗倒伏指数降低;茎秆重心高度以N0最小,N240最高;基部节间秆壁厚度在3个施氮量处理间差异不显著;茎秆充实度、茎秆机械强度和抗倒伏指数随施氮量增加呈降低趋势,但在乳熟期和蜡熟期N120和N240差异不显著。相关分析表明,基部第1节间抗倒伏指数与节间粗度、充实度和第1节间秆壁厚度呈极显著正相关,与第2节间秆壁厚度相关性不显著。逐步回归分析表明,种植密度对小麦抗倒性的影响大于施氮水平。籽粒产量在不同密度处理间差异性不显著,但在不同施氮量间表现为N120和N240处理显著高于N0处理。因此,210万株·hm-2至330万株·hm-2的种植密度和120kg·hm-2的氮素水平在获得较高产量的同时具有较强的抗倒伏能力,是本试验条件下小麦抗倒高产的最优组合。     

A high seed yield and associated attributes of dry matter production achieved by recent Japanese soybean cultivars

Field experiments were carried out in 2014 and 2015 to characterize the associated attributes responsible for dry matter accumulation in high-yielding soybean. We attempted to create a high-yielding environment by introducing narrow-row planting at two planting densities, using a new cultivar ‘Hatsusayaka’ and a current leading cultivar ‘Sachiyutaka’ in an upland experimental field. Dry matter accumulation was assessed in terms of light interception and radiation use efficiency (RUE). Growth analysis was performed to evaluate the crop growth rate (CGR) and the contribution of the net assimilation rate (NAR) and mean leaf area index to CGR. Maximum soybean yields of 590 and 658 g m^?2 were obtained for Hatsusayaka and Sachiyutaka, respectively, in 2015 at the high planting density, with the corresponding maximum aboveground dry matter equaling 1463 and 1331 g m^?2 and maximum LAI equaling 8.5 and 7.6. Although cumulative intercepted solar radiation was lower than in previous studies, early canopy closure at around the beginning of the flowering stage and very high RUE (1.54 and 1.68 g MJ^?2 for Hatsusayaka and Sachiyutaka, respectively) contributed to the high dry matter accumulation. In contrast to the high yield in 2015, continuous excess soil moisture in early August 2014 may have inhibited nodule nitrogen fixation and decreased the nitrogen content, resulting in an extremely high specific leaf area and low leaf greenness, which agrees well with the low NAR during the corresponding period.     

Effects of early planting and cultivars on the yield and agronomic traits of soybeans grown in southwestern Japan

Early planting contributed to increased soybean yields in the U.S. Because a double-cropping system dominates in southwestern Japan, early planting is not performed; it is thus unclear how much the yield potential could be increased by early planting. To address this question, we planted seven U.S. and five Japanese cultivars on around 20 May (early planting), measured the agronomic traits, including yield, yield components, and oil and protein contents, and compared these traits with those of the same cultivars planted on around 20 July (normal planting). In the early planting, the yields of the U.S. cultivars were 322–453 g m^?2, whereas the highest yield among the Japanese cultivars was only 315 g m^?2, which is significantly lower than those of the top five U.S. cultivars, indicating the adaptability of U.S. cultivars to early planting. The increases in yield obtained with early planting were 99–199 g m^?2 and ?26–144 g m^?2 for the U.S. and Japanese cultivars, respectively. The yield obtained by early planting was positively correlated with the pods m^?2, seeds pod^?1, and oil contents, but negatively correlated with the sterile pod rate, 100 seed weight and protein content. In the early planting, the U.S. cultivars had greater pods m^?2, seeds pod^?1 and oil content and less sterile pod rate, 100-seed weight, and protein content than the Japanese cultivars. These results suggest that early planting can increase the yield in southwestern Japan, if cultivars with agronomic traits observed in the U.S. cultivars of this study are grown.     

种植密度对湘农玉13号生长发育和产量的影响

在长沙地区比较研究了玉米新品种湘农玉13号在不同栽培密度下的生长发育和产量形成特性。结果表明：在每公顷3.75万~6.75万株范围内,湘农玉13号产量随密度增大表现先增后降趋势,6.0万株条件下产量最高;随种植密度增加,果穗变短,行粒数显著减少,穗行数未受显著影响;叶面积指数随密度增加而显著增大,但叶片SPAD值变化不明显;在当年天气条件下,密度大于每公顷5.25万株时湘农玉13号倒伏率达到17%以上。因此,为获得高产,湘农玉13号在长沙地区的适宜密度为每公顷6.0万株,但需采取必要措施提高抗倒伏能力。     

植物生长调节剂拌种对扬麦13茎秆生长及籽粒产量的影响

为给高产小麦合理选用生长调节剂提供科学依据,以弱筋小麦扬麦13为试验材料,研究了不同生长调节剂(矮壮素、拌种剂、种衣剂、多效唑)拌种对不同群体小麦茎秆生长及籽粒产量的调节效应。结果表明,拌种处理均能有效降低扬麦13的株高、重心高度及基部节间长度,对茎秆粗度、茎壁厚度、茎秆干重的调节效应因生长调节剂种类不同而存在差异,其中,低密度条件下拌种剂处理的小麦茎壁厚度增加显著,而高密度条件下多效唑处理小麦的茎壁厚度增加显著。生长调节剂拌种处理提高了扬麦13的抗倒伏能力,其作用效果表现为多效唑种衣剂拌种剂矮壮素。相关分析表明,降低植株株高、基部第一节间长度,增加基部第一、二节间壁厚有利于提高植株抗倒性能。拌种处理下小麦产量均高于对照,300×104株·hm-2群体的产量高于150×104株·hm-2群体,均以种衣剂拌种处理增产最明显,平均增幅达11.68%,在倒伏年拌种处理增产效果更显著。     

新疆春小麦品种资源抗倒性评价

为了给新疆小麦抗倒育种提供参考依据,采用田间试验与实验室分析相结合的方法,比较了两种种植密度(100×104和600×104株·hm-2)下40份新疆自育春小麦品种资源的抗倒性,分析了抗倒性与其影响因素的关系。结果表明,与低密度(100×104株·hm-2)相比,高密度(基本苗为600×104株·hm-2)条件下小麦抗倒伏能力、第二节间机械强度、壁厚、茎粗、充实度及地上部鲜重极显著降低,第二节间长度及重心高度极显著增加,茎秆机械强度的降低是小麦抗倒伏能力下降的关键因素。低密度下抗倒性与第二节间长、株高、重心高及第二节间壁厚的关系密切。其中,第二节间长度与小麦抗倒性关系最密切,第二节间越短,抗倒伏能力越强。高密度下第二节间机械强度与抗倒性的关系最密切,茎秆强度越高,抗倒性越强。壁厚可作为评价茎秆机械强度的可靠指标。依据倒伏指数的大小,将40份品种分为高抗型、普抗型、中间型、风险型和易倒型5个级别。供试材料中,80.0%的品种抗倒性较好,其中新春22号为高抗型品种,是较为理想的抗倒伏育种亲本。     

基于结构方程模型的油菜性状和产量关系研究

为量化描述和分析甘蓝型油菜(Brassica napus L.)种植结构的调整以及相关性状变化对产量的影响,本研究利用结构方程模型对连续10年品种选育所得的168组产量和相关性状等数据进行分析,并对不同密度下相关性状和产量数据进行显著性分析。结果显示,在本实验密度范围内随着种植密度的增加,单株产量显著降低,且主要通过单株有效角果数影响单株产量,但总产量呈上升的趋势。研究所选各个性状对单株产量的总效应为:单株有效角果数>分枝数>千粒重>主花序有效角数>主花序有效长>每果粒数。因此,在培育更具有耐密性和对环境适用性的品种的同时,要选育拥有更多单株有效角果数和分枝数的品种以稳定单株产量,综合提高油菜总产量。     

种植密度对熟期不同夏玉米群体光合性能及产量的影响

在大田试验条件下,研究3个种植密度(67 500、82 500、97 500株/hm2)对早熟品种登海618和中晚熟品种登海605的群体光合性能及产量的影响。结果表明,随种植密度增加,单叶净光合速率下降,而群体光合速率、叶面积指数及冠层光合能力均增强,保证了群体光合产物的积累,使玉米总产量提高。两个品种均在97 500株/hm2密度下产量达到最大,且在早收获10 d的情况下登海618产量高于登海605,分别为13 840 kg/hm2和13 080 kg/hm2。随密度增大,登海605倒伏率显著提高,使其产量受到影响。     

国审高蛋白高产大豆蒙1301的选育及栽培技术

蒙1301由安徽省农业科学院作物研究所于2006年以合豆3号为母本,阜豆9号为父本进行有性杂交,经系谱法选择和海南加代选育而成。蒙1301参加2016-2017年国家夏大豆品种区域试验,2年平均产量3 048.0 kg·hm^-2,较对照品种增产2.8%,并表现丰产、稳产、抗病、抗倒伏。该品种生育期106 d,单株有效荚数51.1个,百粒重18.5 g,籽粒蛋白质含量45.26%,脂肪含量19.07%,最佳种植密度为22.5万～27.0万株·hm^-2,在中高肥力田块中易获高产。2018年通过国家农作物品种审定委员会审定。     

不同施氮量和栽插密度下三角形强化栽培杂交稻抗倒伏性与群体质量的关系

 以杂交水稻组合Ⅱ优498为材料,在三角形强化栽培(TSRI)条件下,研究了施氮量和栽插密度对水稻群体质量及抗倒伏能力的影响,并探讨了主要群体质量指标与茎秆抗倒伏性及产量间的关系。结果表明,TSRI下,施氮量及栽插密度对水稻产量、群体质量以及茎秆基部各节间抗倒伏能力均存在显著的调控作用。施氮量为150 kg/hm2与栽插规格40 cm×40 cm配合可提高结实期叶面积指数(LAI)、群体透光率,协调茎秆基部各节间弯曲力矩与抗折弯矩,缓和高产栽培的穗粒矛盾,显著提高籽粒产量;而施氮量增加至225 kg/hm2,应适当降低栽插密度,来缓解群体质量指标的恶化,降低倒伏指数,栽插规格50 cm×50 cm为宜。相关性分析表明,不同施氮量和栽插密度下水稻群体质量指标与茎秆基部各节间抗倒伏能力显著或极显著相关;结合产量表现,尤以齐穗期、齐穗后30 d中部的群体透光率以及齐穗后30 d的根系伤流量对水稻产量及抗倒伏性影响显著。     

Potato (Solanum spp.) in the hot tropics. VI. Plant population effects on soil temperature,plant development and tuber yield

Nine experiments were run at three hot tropical sites (5–12°S, 180–800 m) within Peru to quantify the influence of plant population on soil temperature and growth and yield of the potato.Radiation interception was greatest at the highest plant populations and soil cooling was directly proportional to the amount of crop cover over the soil, but no appreciable effect on the timing of tuber initiation was apparent. More stems per unit land area leading to a higher leaf area index (lai) were primarily responsible for greater interception of radiation at the higher plant populations, although some compensation in stem number per unit land area and in lai at lower populations was evident later in the season.In general, tuber yield increased linearly with increases in planted population over the range studied (2.7–12.5 plants m⁻², and in one experiment to 31.7 plants m⁻²), and was proportional to increases in the amount of intercepted radiation. Tuber yields ranged from 8 to 60 t ha⁻¹ over sites and populations. Vigorous clones with Solanum tuberosum spp. andigena in their genetic background constituted the exceptions to this linear trend, and for these clones yields declined at the highest populations, particularly when the rectangularity of planting vastly deviated from square patterns. Tuber yield of Solanum tuberosum spp. tuberosum and Neotuberosum (S. tuberosum spp. andigena selected for tuberization under long-day conditions) clones did not respond to variations in rectangularity of planting and, probably due to their small stature and early maturity, did not demonstrate signs of intense between-plant competition for tuber yield as measured with the Kira competition density index. In contrast, for clones with Solanum tuberosum ssp. andigena in their genetic background, maximum tuber yield at populations greater than 5.5 plants m⁻² was dependent on the rectangularity of planting, and declined as the latter deviated from squareness.Since the proportion of marketable tubers was scarcely affected by the planting densities, plant population of S. tuberosum ssp. tuberosum clones planted in hot climates should be as close as possible without limiting the amount of soil available for hilling-up.