Effect of yellow rust on yield components of winter wheat in China

Experiments were done in 1983,1984 and 1985 in Beijing and Zhengzhou, People's Republic of China, to determine the relationship of yield components of wheat to the severity of yellow rust ( Puccinia striiformis f.sp. tritici ). Epidemics were manipulated by timing inoculation and fungicide applications. Disease, plant yield, number of ears per plant, number of grains per ear and 1000-grain weight were measured. Analysis indicated that there were interactions among the yield components. However, path coefficient analysis did not detect any statistically significant compensation and showed that there was a positive correlation among yield components. The correlation coefficients between AUDPC (area under disease progress curve, accumulated to each growth stage) and each yield component increased gradually with growth stage, thus providing no evidence of a critical stage at which a yield component was most affected by disease.     

不同土壤水分下大豆根冠互作对产量和农艺性状的影响

为明确不同土壤水分下大豆根冠互作对产量和农艺性状的影响,为大豆抗旱育种提供理论依据,利用耐旱型品种辽豆14与干旱敏感型品种辽豆21进行相互嫁接,在结荚期设置正常供水(80%田间持水量)和水分胁迫(50%田间持水量,持续20 d)处理,成熟期测定主要农艺性状。试验结果表明,大豆地上部农艺性状和产量主要由地上部基因型决定,但水分胁迫下也会受到根系基因型的影响。正常供水与水分胁迫下,与辽豆21相比,辽豆14接穗的株高平均提高24.3%和14.8%,主茎节数分别平均提高19.6%和15.3%,分枝数分别平均提高60.2%和90.6%,单株生物量平均提高57.1%和87.1%,单株荚数平均提高70.0%和92.3%,分枝荚数平均提高159.9%和197.9%,分枝瘪荚率平均降低57.8%和60.4%,最终单株粒重平均提高19.9%和54.9%。与辽豆21自身嫁接植株相比,水分胁迫下,嫁接辽豆14砧木使单株荚重、单株荚数、单株粒数、百粒重和单株粒重分别显著提高了45.8%、27.4%、21.7%、5.2%和20.4%,产量性状的提高与主茎第9～15节位间有效荚数的提高有关。因此,通过地上部与根系的协同改良是提高大豆抗旱性的重要途径。     

不同耕作方式对北疆夏大豆荚粒空间分布及产量的影响

采用大区试验设计,研究滴灌条件下翻耕覆膜(TP)、翻耕(T)、旋耕(RT)、免耕(NT)四种耕作方式对北疆复播大豆的农艺性状、单株荚数、粒数的空间垂直分布、每荚粒数及产量的影响。结果表明,夏大豆的主要农艺性状基本表现为土壤实施耕作处理均优于免耕,其中以翻耕覆膜的效果最好,翻耕次之;单株荚数和粒数的空间垂直分布因耕作方式而异,翻耕覆膜、翻耕、旋耕的主要分布于主茎的中层和上层,免耕的主要分布于主茎中层和下层;不同荚粒的数量均与单株产量呈正相关,其中2粒荚和3粒荚的数量是构成不同耕作方式单株产量的主体,相关系数分别为r=0.99**和r=0.98**;各类荚的数量均以翻耕覆膜的最多,使得其单株荚数和单株粒数的数量均最多,与其它各处理均达极显著差异水平(P0.01),其产量分别比翻耕、旋耕、免耕的增产7.43%、10.85%和16.05%。     

Evaluation of oilseed rape seed yield losses caused by <Emphasis Type="Italic">Leptosphaeria biglobosa</Emphasis> in central China

Phoma stem canker of oilseed rape (Brassica napus), caused by Leptosphaeria maculans/L. biglobosa is a globally important disease. Severe phoma stem canker symptoms have been observed on winter oilseed rape in China but the seed yield loss caused by this disease remains unknown. In May 2012 and May 2013, 17 and 13 crops were surveyed, respectively, in seven counties of Hubei Province, central China. Stems with phoma stem canker disease symptoms were sampled for pathogen isolation and identification. Only L. biglobosa was identified by culture morphology and species-specific PCR; no L. maculans was found. To evaluate the yield losses, yield components (number of branches per plant, number of pods per plant, 1000-seed weight, number of seeds per pod) were assessed on healthy and diseased plants sampled from crops in four counties and on plants from inoculated pot experiments (plants of three cultivars were inoculated at the green bud stage by injecting L. biglobosa conidia into the stem between the first and second leaf scars). Results of the field surveys showed that diseased plants had 14–61% less branches and 32–83% less pods than healthy plants, respectively. The estimated seed yield loss varied from 10% to 21% and from 13% to 37% in 2012 and 2013, respectively. In the pot experiments, there were no differences in numbers of branches or pods but there were differences in number of seeds per pod between inoculated and control plants. For the three cultivars tested, the inoculated plants had yield losses of 29–56% compared with the control. This study indicates that L. biglobosa could cause substantial seed yield loss in China.     

不同灌溉模式对中麦349生长发育的影响

在田间限量灌溉条件下,以小偃22为对照,研究了4种灌溉模式对中麦349干物质转移效率、籽粒灌浆速率、产量及其构成因素、土壤含水率等方面的影响.结果表明,不同灌溉后各营养器官干物质转移量及对籽粒的贡献率均降低,叶源的光合性能提高,花后光合产物向籽粒的分配量增加;籽粒灌浆期延长,中后期灌浆速率提高,粒重增大;穗数、穗粒教、千粒重以及产量均提高.相同灌溉模式下,中麦349较对照干物质转移量及对籽粒的贡献率均较大,但各灌溉模式干物质转移量及对籽粒贡献率均较对照下降幅度较大;对照模式下,中麦349较对照营养器官干物质向籽粒运输量大,对籽粒贡献率较大,产量较多次灌溉减产较少,耐旱程度较强.中麦349两水与三水处理无显著差异,以浇越冬水+拨节水+灌浆水产量最高,小偃22以浇越冬水+拔节水模式产量最高.在浇一水模式中,两品种均以浇拔节水产量较高.     

4个PGPR菌株拌种对干旱条件下蚕豆生长及产量的影响

于播种前,以5×108 CFU/mL浓度的PGPR菌株B9601 Y2, FZB42, B2 和 B9拌种蚕豆,在全生育期土壤重度干旱条件下,与清水拌种相比,它们均能提早出苗,促进幼苗生长,增加植株地上和地下重量与荚果数,B9601 Y2,FZB42,B2和B9菌株分别增加蚕豆株荚数0.65个、0.50个、0.05个和0.33个,有效荚数0.68个、0.53个、0.08个、0.28个,果荚重4.56 g、3.36 g、2.13 g、0.36 g,株粒数1.18粒、1.55粒、0.80粒、0.15粒,百粒重5.28 g,5.75 g,3.72 g,2.50 g,豆粒产量14.49%,12.04%,6.28%,2.21%。     

Effects of Rhynchosporium secalis at specific growth stages on barley grown in a controlled environment

Under controlled environmental conditions, inoculation of barley at five growth stages with Rhynchosporium secalis reduced grain yield by up to 30%. Greater yield losses resulted from inoculations carried out after tillering than from those during or before tillering. Most of the yield loss was due to a reduction in the number of heads per plant. The number of grains per head was reduced only when plants were inoculated at mid- or late-tillering growth stages. The mean weight of individual grains was not reduced significantly by any treatment. Inoculation at stem elongation also resulted in less leaf area and water use, and delayed anthesis. Inoculation affected root dry weight more than shoot dry weight and all inoculations reduced root dry weight at the boot growth stage     

Influence of take-all epidemics on winter wheat yield formation and yield loss

ABSTRACT The effects of take-all epidemics on winter wheat yield formation were determined, and disease-yield relationships were established to assess the agronomic efficacy and economic benefits of control methods. Epidemics were generated in naturally infested fields by varying cropping season, crop order in the rotation, and experimental fungicide seed treatment. Disease incidence and severity were assessed from tillering to flowering. Yield components were measured at harvest. Models simulating the formation of the yield components in the absence of limiting factors were used to estimate the losses caused by take-all. Losses were predicted by the disease level at a specific time or the area under the disease progress curve, reflecting accumulation during a specific period. Losses of grain number per square meter and 1,000-grain weight were linked to cumulative disease incidence between the beginning of stem elongation and flowering, and disease incidence at midstem elongation, respectively. Yield losses were accounted for by both cumulative disease incidence between sowing and flowering, and disease incidence at midstem elongation. Results confirm the importance of nitrogen fertilization in reducing the impact of take-all on wheat.     

Problems of herbicide assessment in peanuts in Jamaica

Delays of 40 or 60 days in weeding peanuts (Arachis hypogaea L.) gave lower yields and fewer pods per plant but did not affect seed number per pod. Yield, pod number per plant, seeds per pod and mean weight per seed were all less in unweeded plots. In three herbicide trials crop yields were not closely correlated with crop vigour scores made several weeks before crop maturity, or with weediness scores. Correlations between yields and weed dry weights were better, but certain high-yielding herbicide treatments gave poor weed control and in some cases had low crop vigour scores. Most yield differences reflected differences in pod number per plant, with additional smaller compensating or additive effects on the other components. Certain herbicides apparently gave high mean seed weights without diminishing seed numbers per pod. Pre-emergence alachlor was the most promising herbicide, combined with preplant incorporated vernolate if nutgrass was serious. Napropamide and metobromuron merit further testing.     

灌浆天数对北方白菜型冬油菜产量和品质的影响

为了研究北方白菜型冬油菜在灌浆成熟过程中产量和品质性状的特征特性变化,以白菜型冬油菜陇油12号和09鉴8为材料,分析冬油菜在终花后10、20、30、40、45 d的植株、角果、籽粒形态和干鲜重,产量和品质性状的变化。结果表明,随着籽粒灌浆成熟,植株和角果颜色呈墨绿—青绿—黄绿—蜡黄—肤白色变化。角果中籽粒大小呈小—大—小变化,种子颜色呈绿色—褐绿相间—褐色—紫色—黑色变化。植株、角果、籽粒鲜重呈先增加后降低的单峰变化曲线,基本呈抛物线状,且分别在终花后20、30、40 d鲜重达到最大,而植株、角果、籽粒干重呈先增加后保持不变的变化趋势。同时千粒重、单株产量、经济系数也呈先增加后保持不变的S型增长曲线,且在终花后30 d达到最大,之后保持不变。相关分析表明,灌浆时间长短与籽粒鲜重、千粒重、经济系数呈极显著的正相关关系,相关系数分别为0.991、0.962、0.968(P0.01);与单株产量、含油率呈显著的正相关关系,相关系数分别为0.947、0.940(P0.05);与蛋白质呈显著的负相关关系,相关系数为-0.886(P0.05)。通过主成分分析方法打分,各处理的综合得分排名为40 d45 d30 d20 d10 d,因此,籽粒灌浆天数对白菜型冬油菜的产量和品质影响明显。综合评价得出,蜡黄期(约终花后40 d)产量和品质等性状达到最佳,是收获的最适宜时期。     

An advisory model for control of Puccinia recondita in winter wheat

Epidemics ofPuccinia recondita and resulting yield loss of winter wheat were studied in field experiments over three seasons in the Netherlands. Results are reported and used to construct an advisory model for control of brown rust, based on rust monitoring. If the fraction of leaves with rust (I) at a certain development stage is determined, the average number of rust sori per leaf (M) was estimated by: M=EXP(1.84+1.39ln(ln[1/(1-I)]). The final number of sori per leaf (Mf) at early dough was forecast by an exponential growth: Mf=M·EXP(RGR·t). The relative growth rate (RGR) averaged 0.163/day and the forecasting period, t, until early dough, was derived from published data. The forecast number of sori-days per leaf (S, AUDPC-value) was then obtained by: S=(Mf-M)/RGR. Yield loss (kg/ha) by brown rust was 1.15 times the number of sori-days per leaf at low rust intensities. The efficacy of the fungicides used was 85%. The forecast avoidable yield loss (L, kg/ha) was calculated by: L=0.85 (1.15 S). Economic thresholds for brown rust control at different development stages are given for Dutch wheat fields at a cost level of 270 kg/ha for one fungicide application.     

不同生育阶段灌水处理对糜子农艺性状及产量的影响

在年降雨量不足40 mm的甘肃省敦煌市,以陇糜10号为指示品种,研究了不同生育阶段灌水处理对糜子主要农艺性状及产量的影响,应用灰色关联度法分析了主要农艺性状与产量的相关性。结果表明：水分亏缺延迟糜子成熟,延长了拔节至抽穗阶段的生长发育天数;生育期内任何阶段水分亏缺都降低了糜子株高、千粒重和产量,主穗长缩短,主茎粗变细,抽穗灌浆期水分亏缺极显著地影响单株穗重、单株粒重及单位面积穗数。不同土壤水分条件下,糜子单株粒重、单株穗重、千粒重、株高、主茎粗、主穗长、单位面积穗数都与糜子产量相关性较大。     

The effect of leaf rust (Puccinia hordei) on yield response in barley (Hordeum vulgare L.) crops with different yield potentials

The effect of leaf rust was investigated on field-grown crops, in two consecutive seasons, each at a single location, using a non-replicated design. The experiments involved three crops and 10 distinct epidemics in the 1987/8 season, and four crops with seven epidemics in the 1988/9 season. The epidemics were concurrent in each season in subplots within each crop, and the yield range was from 2.2–9.0 t ha⁻¹ in nil-diseased plots. Variation in the experiments, assessed as the percentage coefficient of variation, was in the same range as similar, but replicated, experiments with fewer treatment combinations. Early sowing and high agronomic inputs were associated with greater leaf areas, green area durations and yields than in comparable crops sown later or with lower inputs. Disease intensity was described both by per cent disease severity and by the effect on green area. Disease reduced yield mostly via reduced number of fertile ears (mean 31% for all crops) and grain weight (21% mean reduction). Reductions in these components were greater in the 1987/8 season than in the 1988/9 season, but there was no consistent effect associated with yield potential. The number of grains per ear was affected much less (2.5% mean for all crops) than the other components. There was little evidence for compensation between yield components.     

黄土高原旱地豌豆早播增产机理研究

通过定位试验,探讨了黄土高原旱地不同播种期对豌豆产量的影响,供试材料为绿豌豆(高产品种)和燕农2号(低产品种).结果表明,不同播种期对高产豌豆品种出苗情况的影响大于对低产品种的影响.豌豆提前播种,可以增加低产品种的单位面积干物质积累量,但对高产品种的影响不显著.豌豆提前播种,可以提前达到盛花期,高产品种的盛花期早于低产品种的盛花期,在盛花期有较长时间避开六月份的高温天气,有利于高产.豌豆提前播种,可以增加高产品种的产量,显著增加低产品种的产量.有利于产量构成因素的形成,提高籽粒水分利用效率.     

黑龙江省不同年代育成代表性大豆品种产量因子对施肥水平的响应

为了明确黑龙江省不同年代育成大豆品种对施肥水平响应的变化趋势,以黑龙江省不同年代育成的合丰25、合丰35、绥农14、合丰39、垦丰16等5个主栽大豆品种为材料,研究不同年代育成大豆品种在不同施肥水平条件下农艺性状及产量因子的变化规律。结果表明,黑龙江省不同年代育成大豆品种在不同施肥水平条件下,单株产量、主茎节数、单株荚数、光合速率等性状改良效果明显,株高、主茎节数、单株粒数、单株叶面积也得到了不同程度的改良,单株叶面积向着更适于密植栽培的清秀型发展;农艺性状和产量因子对低施肥水平适应能力的改良主要是由于单株荚数显著提高的结果;对中等施肥水平适应能力改良主要是由于光合速率显著提高的结果;对高施肥水平适应能力增强主要是由于光合速率和主茎节数极显著提高的结果。     

Red leaf blotch (Dactuliochaeta glycines) of soybeans (Glycine max) and its relationship to yield

Red leaf blotch of soybeans, caused by Dactuliochaeta glycines, was evaluated on soybean plants in field plots located in Zambia. Two experiments were conducted in each of two seasons. Experiment 1 had four cultivars that were either fungicide-sprayed or not sprayed. Disease severity was greatest on leaves at the lowest nodes from early vegetative through the reproductive growth stages. Area under the disease progress curve (AUDPC) values and percentage of nodes defoliated at growth stage R5 were significantly ( P  = 0.05) greater in unsprayed plots for all cultivars in both seasons. Yield losses ranged from 8 to 37% while reduced seed size ranged from 21 to 29% for the four cultivars. Number of pods per plant in fungicide-sprayed plots did not differ from those in unsprayed plots. However, the number of seeds per plant and seeds per pod were significantly ( P  = 0.05) greater in sprayed than unsprayed plots for some cultivars. In experiment 2, cultivar Tunia was either fungicide-sprayed at different times or not sprayed. The lowest attached leaf had the most variation in the amount of disease while ratings of the most median leaf in the canopy were generally less variable. The AUDPC values calculated from the lowest attached leaf, the mean of all attached leaves, and the median attached leaf differed significantly ( P  = 0.05) the number of times plants were sprayed with fungicide. Defoliation and vertical incidence of red leaf blotch from lower to higher nodes were significantly ( P  = 0.05) reduced in fungicide-sprayed plots in one season, but not the other. One thousand-seed weight and yield differed significantly ( P  = 0.05) with treatment as one application of triphenyltin acetate increased yields by 18% over unsprayed plots in season 1. One thousand-seed weight and yield, regressed on the AUDPC for the median leaf in the canopy, explained 92 and 72% of the variation, respectively.     

宁夏南部山区冬小麦抗旱指标鉴定研究

为了更快速有效地利用现有资源,选育适宜宁南山区旱地种植的冬小麦新品种,本试验通过抗旱系数、主成分分析、相关分析及聚类分析等方法对8个品种12个性状进行研究。结果表明:8个品种根据抗旱系数不同,可分为抗旱性强、中、弱3个等级;12个性状的主要信息主要集中在4个主成分中,累积贡献率达93.40%,这4个主成分因子主要反映产量、抗旱系数、穗长、穗粒数、千粒重、单株粒重、株高、不实小穗数、颖花结实率9个性状。产量、穗下节长和株高与抗旱系数间为显著或极显著正相关。通过聚类分析将8个品种聚为3类,第一类包含3个品种,分别是Z0217-3,Z0231-3和对照中引6号,这三个品种的产量、抗旱系数、穗下节长、千粒重及株高等主要指标在第三类和第二类之间,但穗长、穗粒数及单株粒重在三类中平均值最低。第二类包含2个品种,分别是98-5808-1和Z0228-2-1,这两个品种的穗粒数、单株粒重和不实小穗数三个指标平均值最高,但产量、抗旱系数、穗下节长、千粒重等指标平均值最低。第三类包含3个品种,分别是Z0349-4,08AWS089和晋太0509,这三个品种平均产量高,抗旱系数高,平均穗长最大,平均穗下节长最长,平均结实小穗数最多,千粒重最大、株高最高。     

Effect of foliar diseases of wheat on the physiological processes affecting yield under semi-arid conditions

The effects of Septoria leaf blotch (caused by Mycosphaerella graminicola) and leaf rust (caused by Puccinia recondita ) on the physiological processes affecting yield were studied under semi-arid conditions in Israel. In the absence of water stress, photosynthetic activity decreased as the rate of disease development increased. Transpirational activity was reduced in leaves infected by Septoria leaf blotch, but intensified in leaves with slight leaf rust infections (0.5-5% severity). When leaf rust seventy exceeded 5%, the transpirational water loss declined. Both diseases were associated with a decrease in the maximum rate of grain-weight accumulation, but did not affect the duration of weight accumulation. An inverse linear relationship between disease and final grain weight was observed. Under conditions of water stress, photosynthetic activity of leaves slightly infected by Septoria leaf blotch (1-5"., severity) was greater than that of uninfected leaves. Severely infected leaves (" 25% severity) photosynthesized the least. Both diseases were associated with a decrease in the maximum rate of grain weight accumulation, but the duration of accumulation was longer in tillers with a slow rate of disease development than in uninfected tillers. The relationship between disease and final grain weight in these cases was parabolic; yield was increased at low levels of infection. Theoretical explanations and practical implications of these phenomena are presented and discussed.     

The effect of powdery mildew (Erysiphe graminis f. sp. hordei) and leaf rust (Puccinia hordei) on spring barley in New Zealand. II. Apical development and yield potential

Reduced yields caused by powdery mildew and leaf rust in two seasons were associated with reduced plant growth. Combinations of early, late and full epidemics in one season, and 12 epidemic combinations in the second, were designed to identify crop sensitivity to disease by comparing growth and development with healthy plants. Early epidemics reduced ear number by increasing tiller death, and reduced grain number by effects on spikelet, floret or grain abortion, depending on the type of epidemic. Epidemics later in crop growth increased floret and grain abortion and also reduced grain weight.
There was no compensation by later-determined components for reduced growth and delayed development at earlier growth stages. Plants infected at early growth stages were more sensitive to late infections, seen as effects on the later-determined components, than plants which were healthy initially. Interactions occurred between epidemics at different times and are likely to occur between diseases and other constraints.     

Foliar Application of Silicon,Sulfur, and Flowering Fruit Set Biostimulant on Canola

This experiment was conducted to study the effects of foliar application of silicon, sulfur, and flowering fruit set biostimulant on canola in the farmer’s condition in Darzian, 12?km from Marivan city in the northwest of Iran. The experimental layout was designed as a split-split plot in a randomized complete-block design, with three replications during two consecutive growing seasons, 2017–18 and 2018–19. The main factor included silicon application at two levels: control (0: non-application) and silicon application at 2?kg ha^?1. Sub-factor was sulfur spraying at three levels (0, 1, and 2?L ha^?1) and sub-sub-factor was Tecamin flower (Agri Tecno Fertilizantes, Valencia, Spain) spraying as a flowering fruit set biostimulant at three levels (0, 1, and 2?L ha^?1). The results of the combined analysis showed that the number of grains per pod and biomass were increased significantly at the 1% level by silicon application. Sulfur application improved 1000-grain weight, grain yield, and biomass. This increase was 7.42% for grain yield. Tecamin also significantly increased all traits, including fertile and infertile pod numbers, grain number per pod, 1000-grain weight, grain yield, and biomass. As the most important economic traits, Tecamin increased grain yield by 14.12% compared to controls. Among the treatments, the effect of Tecamin on increasing grain yield was superior. In this experiment, some traits were significantly affected by interaction effects of treatments.