Application Effects of Ultra-fine Powder Shaped Maize Seed Coating Agent in Spring Sowing areas in northeast China

The research explored adaptability maize seed coating agent in spring sowing and effects of ultra-fine powder shaped areas in northeast China. The results showed that germination potential and rate both improved around 5% and the num- ber of root increased by 4% in the treatments with ultra-fine powder shaped maize seed coating agent compared with the control group without seed coating. What＇s more, the treatments with ultra-fine powder shaped maize seed coating agent took advantages in terms of fresh weight of seeding, stem diameter, and dry weight. It is notable that control effects on underground insects performed the best, with per- centage over 94%, which is more excellent relative to other agents in markets. Therefore, ultra-fine powder shaped maize seed coating agent can be widely applied in spring sowing areas in northeast China, without side effects.

Effects of Sowing Periods on Growth and Development,Yield and Quality of Maize in Cold Area

In order to determine the most suitable sowing periods for maize in the cold area of Harbin City,the field test method was adopted.From 2018 to 2019,the main maize variety Xianyu 696 which was planted in Harbin City,Heilongjiang Province,was used as the test material for the six-sowing-period treatment experiments.The sowing period settings were as the followings:April 20(T1),April 24(T2),April 27(T3),May 4(T4),May 11(T5)and May 18(T6).In the experiment,the effects of different sowing periods on the growth and development,yields and quality of maize were studied.The results showed that the maize through T1 treatment had the longest growth period,the lowest height and the highest ear height,and the highest grain protein content.The maize through T6 treatment had the highest height and ear height,as well as the highest starch and oil content.And the grain crude fat,soluble protein,soluble sugar and the moisture content increased and then decreased with the delay of the sowing period.The maize through T4 treatment had the highest content of soluble protein.However,other quality indicators and the number of rows,the length of the bald tip,the number of grains per spike and the weight of 100 grains first increased and then decreased with the delay of the sowing period.The dry matter accumulation through T4 treatment was significantly higher than the ones through five treatments,and the 100-kernel weight and other ear-grain traits were the highest,the maizes through T4 treatment increased the yield by 21.54%compared with that through T1 treatment.Thus,the most suitable sowing period for the maize in the cold area of Harbin City was from May 4 to May 11.It provided technical supports for guiding maize planting in the cold area of Harbin City.

Effects of Sowing Depth and Sowing Equipment on Growth and Yield of Mechanized Sowing Maize

Taking Zhongyu 3 as the experimental variety,this paper analyzed the effects of different sowing depths(5 cm and 8 cm)and sowing equipment(ZHSB-10 medium-sized sowing machine and 2B-2 small sowing machine)on the growth,yield and components of yield of mechanized sowing maize,to provide references for mechanized maize production in southwest ecological zone.The results showed that the germination rate,plant height uniformity,and most agronomic traits of maize plant were higher at the sowing depth of 5 cm;with the growth of the maize,the effects of the sowing depth on agronomic traits of maize gradually declined;the effects of the sowing depth on the empty stalk rate,double ear rate,lodging rate,and lodging and stem broken rate were smaller;the sowing depth of 5 cm could increase the yield of mechanized sowing maize and most yield traits of maize.Different sowing machines had smaller effects on the germination rate,plant height uniformity,and agronomic traits of all growth stages,empty stalk rate,double ear rate,lodging rate,lodging and stem broken rate,yield,and components of yield of mechanized sowing maize.

Maize kernel weight responses to sowing dateassociated variation in weather conditions

Variation in weather conditions during grain filling has substantial effects on maize kernel weight(KW). The objective of this work was to characterize variation in KW with sowing date-associated weather conditions and examine the relationship between KW, grain filling parameters, and weather factors. Maize was sown on eight sowing dates(SD) at 15–20-day intervals from mid-March to mid-July during 2012 and 2013 in the North China Plain. With sowing date delay, KW increased initially and later declined, and the greatest KW was obtained at SD6 in both years. The increased KW at SD6 was attributed mainly to kernel growth rate(Gmean), and effective grain-filling period(P). Variations in temperature and radiation were the primary factors that influenced KW and grain-filling parameters. When the effective cumulative temperature(AT) and radiation(Ra)during grain filling were 950 °C and 1005.4 MJ m-2, respectively, P and KW were greatest. High temperatures(daily maximum temperature [Tmax] > 30.2 °C) during grain filling under early sowing conditions, or low temperatures(daily minimum temperature [Tmin] < 20.7 °C) under late sowing conditions combined with high diurnal temperature range(Tmax-min> 7.1 °C) decreased kernel growth rate and ultimately final KW. When sowing was performed from May 25 through June 27, higher KW and yield of maize were obtained. We conclude that variations in environmental conditions(temperature and radiation) during grain filling markedly affect growth rate and duration of grain filling and eventually affect kernel weight and yield of maize.

Morphological and Phenological Attributes of Maize Affected by Different Tillage Practices and Varied Sowing Methods

To check the performance of maize under different tillage practices and varied sowing methods, an experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad. The experiment was carried out in a randomized complete block design (RCBD) with split plot arrangement with three replications. Different tillage practices viz, conventional tillage, minimum tillage and deep tillage were kept in main plots while sowing methods viz, flat sowing, ridge sowing and bed sowing were allocated to subplots. The maize hybrid “Pioneer-32T16” was sown on 24th February, 2012. Data pertaining to morphological and phenological attributes of maize showed that tillage practices and sowing methods had a significant effect on Germination count·m-2 (7.8), leaf area per plant (5010 cm2), leaf area index (4.87), crop growth rate (20.69 g·m-2·d-1), plant height (213.04 cm), number of leaves per plant (11.89), days to 50% tasseling (72.44) and days to 50% silking (73.77). Economically, maize sown on ridges under deep tillage gave maximum net income of Rs. 85162 ha-1 while minimum net income of Rs. 56984 ha-1 was found where flat sowing was adopted under minimum tillage system and also more BCR of 1.70 was recorded in ridge sown maize under deep tillage.

Maize ZmSRO1e promotes mesocotyl elongation and deep sowing tolerance by inhibiting the activity of ZmbZIP61

Deep sowing is a traditional method for drought resistance in maize production,and mesocotyl elongation is strongly associated with the ability of maize to germinate from deep soil.However,little is known about the functional genes and mechanisms regulating maize mesocotyl elongation.In the present study,we identified a plant-specific SIMILAR TO RCD-ONE(SRO) protein family member,ZmSRO1e,involved in maize mesocotyl elongation.The expression of ZmSRO1e is strongly inhibited upon transfer from dark to white light.The loss-of-function zmsro1e mutant exhibited a dramatically shorter mesocotyl than the wild-type in both constant light and darkness,while overexpression of ZmSRO1e significantly promoted mesocotyl elongation,indicating that ZmSRO1e positively regulates mesocotyl elongation.We showed that ZmSRO1e physically interacted with Zmb ZIP61,an ortholog of Arabidopsis ELONGATED HYPOCOTYL 5(HY5) and showed a function similar to that of HY5 in regulating photomorphogenesis.We found that ZmSRO1e repressed the transcriptional activity of Zmb ZIP61 toward target genes involved in the regulation of cell expansion,such as ZmEXPB4 and ZmEXPB6,by interfering with the binding of ZmbZIP61 to the promoters of target genes.Our results provide a new understanding of the mechanism by which SRO regulates photomorphogenesis and highlight its potential application in deep sowing-resistant breeding.

基于CERES-Maize模型的华北平原玉米生产潜力的估算与分析

在对DSSAT4.0中CERES-Maize模型进行参数校正和验证的基础上,进一步利用华北地区具有代表性的10个气象站30年(1976～2005年)的气象资料以及华北地区典型的土壤数据展开模拟。结果表明,在一年一季的生产条件下,华北平原各地区玉米多年平均光温生产潜力为13.53～22.56t/hm2;各地区玉米产量在4月下旬至6月中旬的播期范围内均呈随播期的延迟而增加的趋势,对这一趋势和各气象指标进行相关分析表明,在华北北部主要驱动因子是灌浆期平均日辐射量,而华北中南部主要驱动因子是灌浆期的温度。华北平原自北向南,优化播期呈逐渐推迟的趋势:北部怀来地区5月上旬播种较为适宜,北京、乐亭和天津地区以5月下旬至6月初播种产量最高;中南部以6月中上旬播种(夏播)较适宜。

基于CERES-Maize模型春玉米水分优化管理决策

在完成DSSAT(4.0.1.0)中CERES-Maize模型参数的校正和验证之后,利用30年(1976-2005年)的气象资料针对北京地区的春玉米生产进行模拟。结果表明,在充分灌溉的条件下,春玉米4月底播种多年平均产量为11.5 t/hm2,当播期推迟至5月底时产量平均提高了4.1%。推迟播期后,春玉米生育期内降雨分布更加均匀。4月底播期的推荐灌溉量多年平均为150 mm,推迟播期后推荐灌溉量减少了50 mm,水分利用率提高了14.9%。在仅灌底墒水及雨养条件下,推迟播期后WUE则分别提高了25.4%和35.6%。5月底播种时,仅灌底墒水在67%的年份里产量达到充分灌溉的水平,即使在雨养条件下仍在50%的年份里和自动灌溉持平。

Comparative Advantage of Maize Production in Jilin Province

The comparative advantage of maize production in Jilin Province was analyzed based on the sow area index,unit yield index,benefit index and comprehensive comparative advantage index in this study.The results showed that compared with other provinces in China,there was obvious comparative advantage in sow area index and unit yield index of maize in Jilin,the average of which stood for the first and the fourth in China from 2002 to 2006;there was no comparative advantage of benefit index compared with the average value of the whole countries,the average of which stood for the 14th in China from 2002 to 2006;the comprehensive comparative advantage in Jilin provincial maize production showed significant comparative advantage,the average of which stood for the fourth in China from 2002 to 2006.On the basis of the above,the suggestions to develop maize production in Jilin province had been put forward.

Electronic control seed-metering system for precision seeding maize based on fuzzy PID

Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip,an electronic control seed-metering system(ECSMS)for maize single seed precision sowing was designed and a mathematical model for motor control of the ECSMS was determined.The PID parameters were set by Z-N method and fuzzy control.The fuzzy PID control design and Simulink simulation were completed by MATLAB,which reduced response time of the system by 0.23 s and improved the control accuracy.Experiments on the JPS-12 test bench show that the qualification index(QI)of maize seed-metering device with the ECSMS increases by 4.47%,the multiples index(MI)decreases by 1.96%,the miss index(MIX)decreases by 2.81%,and the coefficient of variation(CV)of qualified seed spacing decreases by 5.06%,and the sowing uniformity has been greatly improved.Test results of the soil-tank test bench show that the system has good sowing uniformity and stability.And the QI is 96.74%,the MI is 2.15%,the MIX is 1.10%,and the CV of qualified seed spacing is 16.24%.Under different setting seed spacing and different sowing operation speed,the change range of seeding quality index was within 10%.The results of field sowing test show that the QI was 84.21%,the MI was 2.63%,the MIX was 7.89%,and the CV of qualified seed spacing was 22.15%,which meet the requirements of JB/T 10293-2013‘Specification for single seed planters(precision planters)’and the agronomic requirements for maize precision sowing.The system runs stably and reliably in practical operation and has good operation performance.

鲜食玉米播期与密度对大豆、鲜食玉米间作产量的影响

为探索黄淮海区适宜的大豆、鲜食玉米间作模式,采用鲜食玉米播期与密度二因素裂区设计,研究了不同鲜食玉米群体对大豆、鲜食玉米间作体系作物的产量、农艺性状及作物间相对竞争力的影响。结果表明:鲜食玉米3个播期A1(6月30日)、A2(7月7日)、A3(7月14日)与3个种植密度B1(3.20万株·hm^(-2))、B2(3.80万株·hm^(-2))、B3(4.50万株·hm^(-2))共9个处理不影响间作的产量优势,土地当量比(LER)都大于1;从播期方面看,A1、A2和A3的LER均值分别为1.26,1.20和1.15,差异达到显著水平(P<0.05),A1与A2差异不显著;同一播期不同密度条件下,B2的LER最大,B3居中,B1最小。鲜食玉米播期与密度互作对大豆的产量、百粒重无显著性影响,对株高、茎粗、单株荚数、单株粒数产生了显著性影响;鲜食玉米产量和百粒重随着播期的延后逐渐变小,A3的百粒重仅为A1的69.1%,且同一播期内百粒重随着密度的增加逐渐变小。鲜食玉米播期推后抑制了大豆、鲜食玉米共生后期鲜食玉米资源竞争力的恢复,共生前期大豆占优势地位,共生后期鲜食玉米的资源竞争力逐渐变强。因此,就本研究而言,大豆、鲜食玉米间作体系中鲜食玉米应不晚于7月7日播种,种植密度3.80万株·hm^(-2)有利于大豆、鲜食玉米间作体系总产量的提高。

播期调整对华北北部冬小麦、夏玉米产量和品质的影响

【目的】基于田间分期播种试验,研究华北北部冬小麦、夏玉米播期调整,其生长发育、光合生理特性、籽粒灌浆和产量形成及品质对气候变暖的不同响应,为华北平原农业生产采取措施应对气候变化提供科学依据。【方法】采用分期播种方法,于2017—2023年在华北北部的河北固城农业气象国家野外科学观测研究站开展冬小麦和夏玉米的大田分期(早播10 d、正常播期、晚播10 d、晚播20 d)播种试验,获取冬小麦和夏玉米的生育进程、地上干物质累积和分配、叶片光合特性、籽粒灌浆速率以及产量农艺性状和籽粒营养成分等资料。【结果】冬小麦全生育期随播期推迟而缩短,主要原因在于冬前幼苗期缩短;夏玉米全生育期与播期呈抛物线关系,播期每推迟10 d,幼苗期缩短1.3 d,花粒期和籽粒形成-灌浆期分别延长1.5和1.6 d。冬小麦、夏玉米籽粒灌浆过程对播期调整的响应完全不同,冬小麦籽粒灌浆特征在播期间反应并不敏感,夏玉米籽粒灌浆速率在播期间差异较小,但籽粒形成期、灌浆结束日期和峰值日期因播期推迟顺次延后,且灌浆持续日数因播期每推迟10 d,灌浆持续日数缩短4 d。北方麦区在秋暖和冬暖背景下,冬小麦播种期界限延宽,播期对产量的影响明显减弱,播期推迟配套增加播种量,产量不减且会小幅增产;夏玉米产量随播期推迟明显递减,理论产量播期每推迟10 d递减率1381.50 kg·hm^(-2),但冬小麦和夏玉米晚播20 d产量都凸显跳跃变小。播期每推迟10 d,冬小麦籽粒分配率递增1.67%,夏玉米则递减1.57%,冬小麦收获指数提高0.017,而夏玉米降低0.016。冬小麦和夏玉米叶片光合速率(Pn)对播期的响应亦不同,冬小麦播期间的Pn较为相近,而夏玉米播期每推迟10 d Pn递减率1.21μmol·m^(-2)·s-1。播期调整对华北北部冬小麦、夏玉米籽粒品质不会产生明显影响。【结论】气候变暖背景下我国北方冬小麦延迟播种,延宽适宜播种期是适应气候变暖的积极有效措施,华北平原夏玉米适期早播可避免高温热害影响,有助于稳产增产。

播期及生长调节剂对间作大豆倒伏和产量的影响

以大豆、玉米带状复合种植模式为基础,大豆选用耐荫抗倒伏品种‘渝豆11’,玉米选用半紧凑品种‘成单30’,试验采用两因素裂区设计,主区为播期(A),A1为大豆、玉米同期播种,A2为大豆较玉米晚播14 d,副区为9种不同种类及浓度的植物生长调节剂(B),分别于2022年春季和2023年春季在西南大学歇马科研基地进行试验.研究在大豆、玉米带状间作模式下不同播期及生长调节剂对间作大豆产量及其构成因素、根系形态特征和倒伏及茎秆形态特征的影响,研究结果如下:(1)播期及植物生长调节剂对间作大豆产量及其构成因素具有显著影响.播期上同期播种大豆产量高于晚播大豆(A1>A2),其中A1B5、A1B8处理优于其他处理,其两年平均产量较对照分别增长48.56%、40.92%.A1B5处理的单株粒数、单株粒质量、百粒质量最大,较对照两年平均分别提高33.96%、48.56%、10.93%.(2)播期及植物生长调节剂对间作大豆倒伏及相关指标具有显著影响.晚播大豆平均倒伏率较同期播种大豆增加了20.84%,抗折力、茎粗显著减少,株高、主茎节数显著增加,而节间长在两播期间无显著差异.(3)播期及植物生长调节剂影响间作大豆根系形态特征.在不同生育期,大豆总根长、根尖数总体上同期播种大豆优于晚播.在不同时期,整体上大豆总根长为S3307>DTA-6>6-BA,而大豆根尖数为DTA-6>S3307>6-BA.综上所述,在大豆、玉米带状间作模式下,在初花期喷施DTA-6的产量优于S3307和6-BA,同期播种喷施60 mg/L DTA-6产量最高,其次是50 mg/L S3307,但是S3307处理下的大豆倒伏率较DTA-6更低,且产量与DTA-6差异不显著,更适宜机械化收割,利于应用推广.

不同水分供应条件下春玉米的适宜播期

春玉米是半干旱区重要的粮食作物,但该区降水少且年际变异大,春玉米产量低而不稳。适宜播期的选择有利于作物稳产高产,但适宜播期会随水分供应条件的变化而变化。本文以半干旱区主栽春玉米品种‘郑单958’为研究对象,使用APSIM-Maize模型探究该区分期播种试验的适宜间隔以及不同水分供应条件下[雨养、灌溉60 mm、灌溉120 mm、灌溉180 mm、灌溉240 mm、潜在条件(灌溉量308 mm)]春玉米的适宜播期范围。结果表明:1)以不同供水条件下春玉米产量的5%分位为差异阈值划分播期时,该地区春玉米分期播种试验和模拟的时间步长建议设定为4 d;2)雨养条件下,干旱年、正常年和湿润年春玉米平均产量分别为0.9 t·hm^(-2)、2.3 t·hm^(-2)和5.5 t·hm^(-2),平均水分利用效率分别为0.4 kg·m^(-3)、0.7 kg·m^(-3)和1.5 kg·m^(-3),潜在条件、灌溉240 mm、灌溉180 mm、灌溉120 mm、灌溉60 mm和雨养条件下的适宜播期范围分别为5月6日—6月2日、5月6—29日、5月10—29日、5月14—29日、5月14—25日和5月14—17日,适宜播期范围随生育期供水量的增加而提前和扩大;3)潜在条件下春玉米产量的气象决定因子是生育期辐射量,灌溉240 mm和180 mm时产量的气象决定因子分别是营养生长阶段辐射量和降水量,灌溉120 mm和60 mm及雨养条件下的产量决定因子均为生育期降水量。本文探究了春玉米的适宜播期及其随生育期供水量的变化规律,研究结果可为半干旱区春玉米适水播种提供理论参考。

播期对宁夏引黄灌区不同品种青贮玉米光能利用及生物产量的影响

为探究播期对宁夏引黄灌区麦收后复种不同品种青贮玉米光能利用和生物产量的影响,采用裂区试验设计,选择早熟‘科沃028’(Z)和中晚熟‘利合629’(W)2个青贮玉米品种为主区,设置麦收后3(S1,6月28日)、6(S2,7月1日)、9 d(S3,7月4日)3个播期为副区,共计6个处理,研究不同播期对不同品种青贮玉米光能利用、干物质积累及生物产量的影响,并拟合推测不同品种青贮玉米的最适播期及收获期。结果表明:Z较W处理整体上有更高的叶面积指数(LAI)、光能利用率(LUE)、光合生产潜力开发度(r)、干物质积累量(DM)和生物产量(BY)。Z处理整个生育时期LAI大小顺序均为ZS1>ZS2>ZS3。在生育后期(麦收后95 d),ZS3处理的植株底部透光率(BLT)和LUE较ZS1和ZS2处理分别显著提高13.81%、5.40%和15.02%、23.49%(P<0.05);麦收后107 d,ZS1和ZS2处理的BY与麦收后100 d相比分别显著下降22.47%和17.37%(P<0.05)。各处理在其最适收获期收获,产量大小顺序为ZS1>ZS2>ZS3>WS2>WS1>WS3。相关性分析结果表明2个品种LUE均与其BY呈极显著正相关关系(P<0.001),而与r呈极显著负相关关系(P<0.001)。主成分分析发现ZS2处理综合评价最优。综上所述,建议宁夏引黄灌区早熟品种生长85 d后(麦收后6~8 d播种)收获,而中晚熟品种生长86 d后(麦收后5~6 d播种)收获。

播期和叶面肥喷施对不同玉米品种产量和籽粒矿质元素含量的影响

研究旨在探讨播期和叶面肥喷施对不同玉米品种产量和籽粒矿质元素含量的影响,于2019年5—10月在山东省临沂市设置玉米大田试验,采用三因素裂区试验设计,主处理为5个玉米播期(5月31日、6月6日、6月13日、6月21日和6月28日,分别记作B1~B5),裂区为‘登海605’和‘郑单309’2个玉米品种,裂区-裂区为5种叶面肥喷施处理,分别为去离子水(Water)、氯化钙(Ca)、硫酸锌(Zn)、谷氨酰胺(N)和谷氨酰胺与硫酸锌混合溶液(N+Zn)。于玉米成熟期进行样品采集与分析。结果表明:‘登海605’和‘郑单309’均在B3播期时(6月13日)产量最高,最高产量平均分别为11.9、10.9 t/hm^(2),主要由于该播期下穗粒数最高,表明B3播期是该区域最佳播期,而早播和晚播均会显著降低2个玉米品种的产量。对于‘登海605’,叶面喷施N溶液可略提高早播条件下(B1和B2播期)籽粒产量,而叶面喷施Ca、Zn、N和N+Zn溶液可提高晚播条件下(B4和B5播期)籽粒产量,其中叶面喷施N+Zn溶液的增产效果最好,在B4和B5播期下籽粒产量较对照分别增加45.5%和16.0%。对于‘郑单309’,叶面喷施N或Zn溶液可提高B4播期籽粒产量,而喷施Ca溶液可提高B5播期的籽粒产量。另外,叶面喷施Zn或N+Zn溶液可显著提高‘登海605’和‘郑单309’在B2和B3播期的籽粒Zn浓度。叶面喷施Zn溶液可以显著提高B2和B3播期下‘郑单309’的籽粒Fe、Mn、Cu、N和Mg浓度。以上研究结果为协同实现玉米高产优质栽培和肥料利用效率的提高提供理论依据。

玉米免耕播种自动调偏系统设计与试验

为适应新疆滴灌区宽窄行免耕种植模式,解决传统大型玉米免耕播种机播种过程中触碰根茬、无法精确约束路径、玉米粒距合格率低等问题,结合免耕播种农艺要求,在采用导航定位技术获取播种机当前位置与目标路径间偏差的基础上,设计一种玉米免耕播种自动调偏系统。该系统主要包括避茬装置、液压执行系统和控制系统,通过建立整机力学模型,对避茬装置和液压执行系统进行运动和受力分析,确定避茬装置和液压执行系统关键结构参数,获取避茬装置最佳挂接长度和液压执行系统最大驱动力。进一步优化控制系统,实现避茬装置自动调偏及接收反馈信息功能。对免耕播种避茬装置自动调偏系统进行性能试验,试验结果表明,神经网络PID的期望调偏角最大稳态误差为0.932°,超调量全部小于1%,平均响应稳态误差小于0.9°,满足预期。田间试验结果表明,当拖拉机作业速度不大于1.0 m/s、行间秸秆覆盖量不大于1.0 kg/m^(2)时,避茬率不小于85%,纵向调整距离不大于8.6 m,玉米粒距变异系数不大于21.63%。此时播种机调偏避茬效果最佳,满足玉米免耕播种机农艺指标要求。

春夏播玉米籽粒蛋白质、脂肪和淀粉含量动态累积与分配差异性研究

【目的】研究春夏播玉米籽粒蛋白质、脂肪和淀粉含量动态累积与分配差异性特征,为专用优质玉米品种选育与生产提供参考。【方法】以驻玉216、驻玉902、驻玉927、郑单958、裕丰303为试验材料,授粉后12 d每隔7 d取果穗内籽粒,烘干至恒重,利用近红外光谱技术快速检测玉米籽粒蛋白质、脂肪、淀粉含量,分析籽粒蛋白质、脂肪、淀粉动态累积相关关系,比较春夏播玉米籽粒蛋白质、脂肪与淀粉含量动态累积与分配的差异性。【结果】玉米籽粒蛋白质含量春播先急剧下降后平稳变化,夏播先急剧下降后又升高,呈波浪式变化;春夏播玉米籽粒脂肪含量先上升后下降,淀粉含量随籽粒发育基本呈渐进式增加,蛋脂总量整体呈逐步下降趋势。春夏播玉米籽粒蛋白质、脂肪与淀粉累积速率动态呈锯齿状变化。籽粒蛋白质、脂肪和淀粉分配春播授粉后12~19 d整体呈现为淀粉>蛋白质>其他>脂肪,授粉后26~47 d基本呈现为淀粉>其他>蛋白质>脂肪;夏播授粉后12~18 d整体呈现为淀粉>蛋白质>其他>脂肪,授粉后19~47 d基本呈现为淀粉>其他>蛋白质>脂肪。相关性分析表明,籽粒蛋白质、脂肪、淀粉动态累积量之间呈现极显著正相关关系(P<0.01)。【结论】驻玉216、驻玉902、驻玉927、郑单958、裕丰303春夏播玉米籽粒蛋白质、脂肪和淀粉动态累积与分配受环境影响较大,籽粒蛋白质、脂肪和淀粉动态累积量互为极显著正相关。

大豆玉米复合种植播期、密度和施肥量对大豆农艺性状和产量的影响

为筛选大豆玉米复合种植大豆最佳的栽培措施,采用三因素三水平正交试验,研究大豆播期、密度和施肥量对主要性状和产量的影响。结果表明,选择鲜食玉米与大豆复合种植,玉米收获后大豆复光期长;提高株高、主茎节数、单株有效荚数、单株粒数、百粒重、单株粒重对大豆产量有促进作用,且单株粒数、单株粒重和百粒重对产量有决定性作用。分析结果表明,播种期为4月30日—5月10日,密度为21万~24万株/hm^(2),施肥量为300~375 kg/hm^(2)的最佳栽培技术,可优化复合群体配置获得较高的产量。

基于RecurDyn仿真玉米育种精密播种单体的设计

为解决育种小区玉米播种过程中播种质量和播深均匀性普遍较差等问题,设计出一种玉米小区精密播种单体。该单体针对东北地区采用的免耕形式,通过理论分析对单体的整体结构和关键部件进行优化设计;同时,以前后连杆长度、弹簧刚度系数和弹簧预紧力为试验因素,利用RecurDyn运动学仿真优化软件对安装拉力弹簧的播种单体仿形效果进行仿真与参数优化。田间试验结果表明:设计的精密播种单体播深变异系数为3.47%,符合小区玉米精密播种的作业要求。