Maize/peanut intercropping increases photosynthetic characteristics, ~(13)C-photosynthate distribution,and grain yield of summer maize

Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in Shandong, China. Treatments included sole maize(SM), sole peanut(SP), and an intercrop consisting of four rows of maize and six rows of peanut(IM and IP). The results showed that the intercropping system had yield advantages based on the land equivalent ratio(LER) values of 1.15 and 1.16 in the two years, respectively. Averaged over the two years, the yield of maize in the intercropping was increased by 61.05% compared to that in SM, while the pod yield of peanut was decreased by 31.80% compared to SP. Maize was the superior competitor when intercropped with peanut, and its productivity dominated the yield of the intercropping system in our study. The increased yield was due to a higher kernel number per ear(KNE). Intercropping increased the light transmission ratio(LTR) of the ear layer in the maize canopy, the active photosynthetic duration(APD), and the harvest index(HI) compared to SM. In addition, intercropping promoted the ratio of dry matter accumulation after silking and the distribution of ~(13) C-photosynthates to grain compared to SM. In conclusion, maize/peanut intercropping demonstrated the potential to improve the light condition of maize, achieving enhanced photosynthetic characteristics that improved female spike differentiation, reduced barrenness, and increased KNE. Moreover, dry matter accumulation and ~(13) C-photosynthates distribution to grain of intercropped maize were improved, and a higher grain yield was ultimately obtained.     

冠菌素对玉米抗倒伏能力及产量的影响

在田间条件下，以玉米品种先玉335和郑单958为材料，在八展叶时于叶面喷施不同浓度 (0、0.01、0.1、1和10 μmol/L) 冠菌素 (COR)，研究了COR对玉米抗倒伏能力及产量的影响。结果表明:经10 μmol/L COR处理后，先玉335的株高和穗位高分别比对照降低了7.0%和19.9%，郑单958分别降低了20.8%和18.2%，单株叶面积、节间抗折断力、穗下第8~14节间长度和节间最大直径与对照间亦差异显著。且随着COR浓度的增加，先玉335和郑单958的株高、穗位高、单株叶面积和穗下第8~14 节间长度均逐渐降低；第8~14节间最大直径和节间抗折断力逐渐增大。经1 μmol/L COR处理后，2个供试玉米品种的产量、穗数、穗粒数和千粒重较对照均有所增加，其中先玉335的产量较对照增加了9.9%，郑单958增加了4.3%。综上所述，COR可以提高玉米的抗倒伏能力，不同品种玉米对COR的敏感性不同，其中先玉335抗倒伏的最适COR浓度为10 μmol/L，郑单958抗倒伏的最适COR浓度为1 μmol/L。     

基于条件植被温度指数的夏玉米生长季干旱预测研究

为验证条件植被温度指数(VTCI)在夏玉米生长季干旱预测中的适用性,以河北中部平原为研究区,应用求和自回归移动平均(ARIMA)模型及季节性求和自回归移动平均(SARIMA)模型,对该地区VTCI时间序列数据进行分析建模预测。首先基于49个气象站点所在像素的VTCI时间序列数据,选取不同长度时间序列建立ARIMA模型,并分析时间序列长度与预测精度间关系,以期为时间序列长度选择提供依据;然后选择理想长度的VTCI时间序列数据,分别建立ARIMA模型和SARIMA模型,用于研究区域2017年夏玉米生长季VTCI预测,并分析评价两模型预测精度;最后采用性能较好的ARIMA模型逐像素建模预测,得到2016-2018年9月上旬至下旬VTCI预测结果。结果表明:基于ARIMA模型的VTCI预测精度与时间序列长度未呈现明显的相关关系,但随时间序列长度增加,模型预测精度逐渐趋于稳定;ARIMA模型对干旱的预测精度高于基于SARIMA模型,其1步、2步、3步VTCI预测结果均方根误差较SARIMA模型分别降低0. 06、0. 07、0. 09;ARIMA模型在不同年份夏玉米生长季VTCI1~3步的预测精度稳定性较好,2016-2018年1步、2步和3步VTCI预测结果绝对误差绝对值大于0. 20的像素平均百分比分别为5. 84%、6. 38%、8. 72%。     

Quantitative trait loci mapping for yield-related traits under low and high planting densities in maize (Zea mays)

Average maize yield per hectare has increased significantly because of the improvement in high-density tolerance, but little attention has been paid to the genetic mechanism of grain yield response to high planting density. Here, we used a population of 301 recombinant inbred lines (RILs) derived from the cross YE478 × 08–641 to detect quantitative trait loci (QTLs) for 16 yield-related traits under two planting densities (57,000 and 114,000 plants per ha) across four environments. These yield-related traits responded differently to high-density stress. A total of 110 QTLs were observed for these traits: 33 QTLs only under low planting density, 50 QTLs under high planting density and 27 QTLs across both densities. Only two major QTLs, qCD6 and qWKEL2-2, were identified across low- and high-density treatments. Seven environmentally stable QTLs were also observed containing qED6, qWKEL3, qRN3-3, qRN7-2, qRN9-2 and qRN10 across both densities, as well as qRN9-1 under low density. In addition, 16 and eight pairs of loci with epistasis interaction (EPI) were detected under low and high planting densities, respectively. Additionally, nine and 17 loci showed QTL × environment interaction (QEI) under low- and high-density conditions, respectively. These interactions are of lesser importance than the main QTL effects. We also observed 26 pleiotropic QTL clusters, and the hotspot region 3.08 concentrated nine QTLs, suggesting its great importance for maize yield. These findings suggested that multiple minor QTLs, loci with EPI and QEI, pleiotropy and the complex network of “crosstalk” among them for yield-related traits were greatly influenced by plant density, which increases our understanding of the genetic mechanism of yield-related traits for high-density tolerance.     

云阳县玉米高产栽培技术探讨

云阳县是一个贫困落后山区县,为了改善生态环境,合理利用山区自然资源,保证粮食安全与农民增收,介绍了云阳县玉米高产栽培技术,提出进一步发展玉米生产的几点建议,以指导当地玉米生产。     

遵义县白菜不同配方施肥效果初探

为指导农户生产,进行了6个不同施肥量比较试验.结果表明：白菜施肥量为清粪水1500kg/667m2,尿素20kg/667m2,普钙50kg/667m2,氯化钾13kg/667m2,单产高,经济效益好,可在遵义县推广.     

适雨灌溉下不同施肥模式对机插稻稻田水环境及产量的影响

【目的】探讨江汉平原地区适雨灌溉条件下不同施肥模式对机插稻稻田水环境及水稻生长的影响,为当地机插稻水肥管理措施的改善提供理论和数据支撑。【方法】采用田间小区试验,研究了适雨灌溉条件下,农民习惯施肥(FFP)、70%控释掺混肥+30%尿素(70%CRF+30%N)和有机无机复混肥(OIF)对稻田降雨利用率、田面水氮磷质量浓度的动态变化与径流流失量、干物质积累及水稻产量的影响。【结果】适雨灌溉下,返青期、分蘖期、拔节孕穗期和灌浆成熟期的降雨利用率分别为17.5%、100%、100%和84.2%;基肥和分蘖肥施用过后,FFP、70%CRF+30%N和OIF处理田面水TN、NH4+-N和TP质量浓度迅速提高,在第1天达到峰值,水稻移栽后30 d内70%CRF+30%N处理田面水TN、NH4+-N和TP的平均质量浓度较FFP处理分别降低40.4%、47.4%和0.5%;稻田氮磷径流流失量的90%左右在返青期,10%左右在灌浆成熟期,70%CRF+30%N处理TN、NH4+-N和TP径流损失量较FFP处理分别降低31.4%、30.9%、1.9%;70%CRF+30%N处理在返青期干物质积累量显著低于FFP和OIF处理,移栽-返青期阶段干物质积累量占总积累量比例表现为FFP处理>OIF处理>70%CRF+30%N处理,成熟期OIF处理干物质积累量显著高于70%CRF+30%N和FFP处理,实际产量表现为OIF处理>70%CRF+30%N处理>FFP处理。【结论】适雨灌溉条件下,70%CRF+30%N处理有助于减少稻田氮素流失,OIF处理有助于机插稻干物质积累与产量的增加。     

施肥对猕猴桃鲜果产量及品质的影响

试验比较5个不同施肥水平对坡地猕猴桃果园鲜果产量及其内在品质的影响.结果表明,随着施肥水平的提高,猕猴桃鲜果的产量也明显提高,配方施肥的增产幅度更为明显.在低施肥水平的条件下,增加施肥对提高猕猴桃鲜果品质有正面的作用;高施肥水平对鲜果品质在总体上没有不良的影响.同时,对施用有机肥和配方施肥的作用进行讨论.     

Cause and Consequence in Maize Planting Dates in Germany

An important part of agricultural adaptation is the timing of crop sowing dates, affecting yields and the level of risk incurred during a particular season. Cold stress is especially relevant in maize, Zea mays L., so that the timing of planting in the spring is a tactical response to short‐term weather, but is also subject to strategic planning with regard to longer‐term climate. Both factors compare the potential implications of cold stress to the additional yield obtainable through earlier planting. New cultivars suited to growing conditions in Europe and generally increasing spring temperatures have enabled earlier planting, but it is still dependent on short‐term weather during the planting period. In the context of field‐level decision‐making, a panel regression is used to estimate the relationship between weekly local temperature and precipitation and planting dates at specific sites throughout Germany. Next, localised weather data and planting behaviour are linked to yields at the district (Landkreis) level to show the effects of planting date on yield. Based on these relationships optimal planting dates are explored with some associated costs and benefits. Results show a trend towards earlier planting that follows observed increasing spring temperatures and the availability of more cold‐tolerant cultivars but this advance is buffered by the increasing severity of minimum temperatures during a critical period. Earlier planting potentially increases yield but this is offset by additional management costs and risk. A robust and simple depiction of farmer behaviour in climatic, technological and economic context can help to understand trends in crop management and productivity that effect agricultural landscapes.