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1.
With increased emphasis on bio-diesel fuels, the influence of spring planting on development of brown mustard (Brassica juncea cv. Arid), canola (B. napus cv. Hyola 401) and camelina (Camelina sativa cv. Boa) has become important. Field trials were conducted at Scottsbluff, NE, in 2005 and 2006 at planting dates of 24 February, 24 March, 7 April, 21 April and 5 May, and 3 March, 3 April, 10 April, 27 April, 11 May, and 2 Jun, respectively. Emergence time was shorter with later planting. Flowering date was later with later planting but occurred within a range of degree days (P-days). Fruiting was affected by date and P-days, but seed maturity was not affected by planting date and was unrelated to P-days. Fleabeetle (Phyllotreta spp.) damage was very high in brown mustard and canola. Bird, primarily house finch (Carppodacus mexicanus), feeding was a major problem with brown mustard planted before mid April and in canola, only with the first planting. Camelina was not affected by either. Planting in April gave the best yields, and canola could yield over 2200 kg ha−1. Oil content of the Brassica was highest when planted from late March and later. For camelina, planting date had no effect. In brown mustard and canola, 60-65% of oil was C18:1, in camelina, about 15%. Later planting increased C18:1 content for the three crops. The second fatty acid was C18:2 with 20% in brown mustard, 18% in canola and 20% in camelina. Later planting increased C18:2 in camelina only. The major fatty acid in camelina was C18:3 at 32-37%; earlier planting increased the content of C18:3. In Camelina, C20:1 comprised about 12% of the oil and was highest with April planting. Canola and camelina seeded in April could be grown for oil successfully in western Nebraska.  相似文献   

2.
In order to study the effect of sowing dates on the yield and yield components of two safflower varieties, an experiment was conducted at Agriculture Research Station of Isfahan Kabotar Abad in 2004. A split plot layout within randomized complete block design with three replications was used in the experimentation. Eight sowing dates were in the main plots, consist March 6, March 21, April 6, April 21, May 6, May 21, June 6 and June 21 and two varieties (Isfahan 14 and I.L111) were in the sub plots. The results showed that the number of seed per capitulum and seed yield were decreased significantly as the sowings dates were delayed. The Isfahan 14 variety in comparison with I.L111 produced more fertile capitulum in square meter and also, respectively seed per capitulum. The second sowing date (March 21) produced the highest seed yield (2306.2 kg ha(-1)), whereas the 7th sowing date (June 6) produced the lowest seed yield (622 kg ha(-1)). The effect of variety for seed yield was not significant. Farmers in the Kabotar Abad of Isfahan and in other areas with similar conditions are recommended to plant the Isfahan 14 variety on March 21.  相似文献   

3.
With increased emphasis for diesel substitution, production of brown mustard (Brassica juncea), canola (Brassica napus) and camelina (Camelina sativa) used as biodiesels may increase in the High Plains. Since these are new crops to this region, understanding their growth is critical for their acceptance. The objective was to elucidate the growth pattern of these crops when spring-planted in western Nebraska. Field trials were conducted in 2005, 2006 and 2007 with early May planting. Plots were seeded 2 cm deep at 200 plants m−2. Four plants were destructively sampled at about 28, 40, 53, 61, and 82 days after planting (DAP). Canopy growth was field measured. Canopy heights peaked by 61 DAP at 95, 85 and 70 cm for brown mustard, canola and camelina, respectively. Stem length increased to 82 DAP at the rates of 1.24, 1.22 and 0.85 cm/d for brown mustard, canola and camelina, respectively. Root weight accumulated linearly from 28 to 61 DAP. The Brassica grew roots faster and achieved higher weights than camelina. From 28 to 40 DAP, vine fresh weight accumulated rapidly for these crops, leveled and then gradually declined as leaves desiccated. Vine dry weight increased to 61 DAP and then plateaued. The maximum vine dry weights, reached at 61 DAP, were 4.3, 4.5 and 3.0 g/plant for brown mustard, canola and camelina, respectively. By 61 DAP, pods were present and accumulated dry matter while leaves senesced. Pod fresh weight reached its peak at 61 DAP while its dry weight increased linearly to 82 DAP at rates of 0.36, 0.24 and 0.096 g/d for brown mustard, canola and camelina, respectively. Harvest in 2006 showed no significant (p < 0.05) difference between crops with a mean yield of about 1500 kg ha−1. Fatty acid composition was dramatically different between the crops as previously reported. The growth patterns of these crops indicated that all three would be suitable for production in the northern High Plains.  相似文献   

4.
Seeding depth and soil packing affect pure live seed emergence of cuphea   总被引:2,自引:0,他引:2  
Cuphea viscosissima Jacq. × C. lanceolata f. silenoides W.T. Aiton is a new crop being developed in the north-central USA as an industrial oilseed crop. Adequate plant stand is essential for successful commercial production of cuphea. The objective of this study was to determine the effect of seeding date, depth and soil packing on stand establishment and subsequent crop performance. The study was conducted at Carrington and Prosper, ND, in 2005 and 2006. The experimental design was a randomized complete block with four replicates, with a split–plot arrangement, where the whole plot was a factorial arrangement (2 × 2) of two seeding dates, optimum and late, with or without soil packing after seeding. The subplot treatments were three seeding depths (surface, 13, and 25 mm). The same plot planter was used to adjust seeding depth to 13 and 25 mm. Each experimental unit had six rows 4.6-m long with a between-row spacing of 0.31 m. Traits evaluated were pure live seed emergence (PLSE), plant stand, plant height at harvest and seed yield. The main effect for seeding date did not have an effect on PLSE and resulted in adequate stands from both late May and mid June plantings averaged across environments. The seeding depth by soil packing interaction was significant for PLSE, plant stand and seed yield. Pure live seed emergence, plant stand, and seed yield were greater if the soil was packed compared with non-packed for the surface seeded treatment. The soil packing treatment did not influence PLSE, plant stand, or seed yield at the 13- and 25-mm seeding depths. Plant stands obtained from the non-packed surface and 13-mm seeding depths was adequate for high seed yield, as the plants branched to compensate for the lower plant density. Although surface seeding with packing produced satisfactory plant stands, reliance on timely rainfall is required for this to be successful. For this reason, the recommendation for seeding at the 13-mm depth without soil packing would ensure a better chance for sufficient soil water absorption by the seed to initiate germination. If surface seeding is practiced, a roller-packer to incorporate seeds and firm the seedbed after planting is recommended.  相似文献   

5.
Five storage temperatures and three planting dates were used to obtain differences in seed performance. As seed storage temperature increased, average stem number per seed piece significantly increased. Stem number also increased with later planting dates. Germination tests, conducted under controlled temperatures, resulted in a curvilinear response with the least stems per seed piece at 10°C. a maximum stem number at 16°C and a slight decline in number at 21°C. The major effect of planting date was manifested through differences in germinating temperatures which resulted in increased stem number with later plantings. Yield of U.S. No. 1 tubers (5cm or 112 gm minimum) declined significantly as stem number increased. In the first planting, the correlation coefficient between stem number per seed piece and yield was r = ?0.95. Increased stem number and declining yield were attributed to advanced physiological age resulting from exposure to higher temperatures in storage and in the field. As stem number increased with planting date, tuber number also increased. The correlation coefficient between stem and tuber number for the first planting date was r = 0.92. The relationship declined significantly on the third planting date to r = 0.46. From these results it was concluded that economic yields are influenced by stem and tuber number which in turn can be manipulated by control of seed storage temperatures and planting dates.  相似文献   

6.
SoySim is a new soybean (Glycine max, L. Merr) simulation model that combines existing approaches for the simulation of photosynthesis, biomass accumulation and partitioning with several new components: (i) flowering based on floral induction and post-induction processes, (ii) leaf area index based on logistic expansion and senescence functions, (iii) integration of canopy photosynthesis using a beta function, and (iv) yield simulation based on assimilate supply and seed number. Simulation of above ground dry matter (ADM) and seed yield by SoySim were validated against data from field studies at Lincoln (NE), Mead (NE), Whiting (IA), and West Lafayette (IN) that included 147 site-year-cultivar-planting date-plant-plant population combinations. In each of the four field studies, agronomic management other than planting date and plant population was optimized to achieve growth with minimal limitation from pests, nutrients, or other controllable factors. SoySim requires just two genotype-specific and two crop management-specific input parameters and yet provides reasonable accuracy in simulating growth and yield under optimum growth conditions across a wide range of sowing dates, plant population, and yield (2.5–6.4 Mg ha−1) in the North-Central U.S. Corn Belt. Simulated seed yield had a RMSE of 0.46 Mg ha−1. Few cultivar-specific parameter input requirements, lack of requirements for specification of key developmental stages, and mechanistic treatment of phenological development, canopy photosynthesis, and seed dry matter accumulation give several advantages to SoySim for use in research and for use as a decision-support tool to evaluate the impact of crop management options on yield potential in favorable environments.  相似文献   

7.
Both crambe (Crambe abyssinicia, Hochst) and rape (Brassica napus L. and Brassica rapus L.) are cool season crops, thus they may have potential as irrigated, winter rotational crops in the low deserts of the southwestern United States and northern Mexico. Currently, no information is available on the effects of fall planting date on the production of these crops. The objectives of this study were (1) to determine the effects of fall planting date on flowering patterns, seed yield, and oil content of crambe and two species of rape, and (2) to determine the suitability of rape and crambe as rotational crops for the low deserts of the southwestern United States. Nine cultivars of rape and one cultivar of crambe were planted at the Maricopa Agricultural Center on three dates in November and December of 1995 and four dates from October through December of 1997 on a variable Mohall sandy loam soil (fine-loamy, mixed hyperthermic, Typic Haplargid). Five of the rape cultivars were B. napus types and the remaining four were B. rapus. One was an industrial rape (R-500) and the other eight were Canola types. Seed yield, oil concentration, and seed weight were determined. In 1996, the percent of plants flowering was observed visually on a periodic basis. In 1998, detailed imaging of flowering was done periodically using a digital camera. Planting date affected water application by controlling the length of the growing season. Our plants were taller, oil content was higher, seed weights were comparable, days to flowering were more than doubled, and seed yields were lower than plants from spring plantings in the Northern Great Plains. In both years of the study, the highest yields were obtained when rape and crambe were planted in November, which would fit well with cotton harvest dates. Lodging was a serious problem in rape. Crambe was sensitive to frost and could fail in some years. Only R-500 matured early enough to be used in rotation with current cotton cultivars. In addition to the onset of flowering, the automated method for estimating flowering was able to detect differences between Brassica species and cultivars and to measure the duration of flowering. Each species had a distinctive flowering pattern. Planting dates also affected the pattern and efficiency of flowering. Reproductive efficiency appeared to change with planting date and in general, October and November planting dates produced seed with higher oil content and seed weights than December planting dates.  相似文献   

8.
播期和密度对高油高产大豆合丰50脂肪含量及产量的影响   总被引:5,自引:0,他引:5  
以合丰50为材料,分7个播期、5个密度,研究不同播期及密度对其品质、产量及农艺性状的影响.结果表明:播期及密度对高油高产大豆品种合丰50的产量有较大的影响,随播期的延迟和密度的增加,该品种的产量呈先上升后下降的变化趋势,差异达到极显著水平;播期埘油份含量的影响较大,而且规律性极强,即随播期的延迟各密度处理合丰50的油份含量下降.不同密度处理对油份含量的影响较小,而且规律性也不强.合丰50的最佳播种时期为5月9日左右,而最适密度为25万株·hm~(-2),此时可获得最高产量和较高的含油量.  相似文献   

9.
一种高利用价值油料作物—亚麻荠的研究进展   总被引:2,自引:0,他引:2  
本文在对亚麻荠的栽培和育种现状进行阐述的基础上,重点概括了其种子中两种主要化学成分油脂和蛋白,具体包括油脂含量和脂肪酸组成、脂质活性成分及降血脂作用、油脂在生物能源上的应用,蛋白含量和氨基酸组成、蛋白饼粕加工利用等方面的研究状况。最后分析了约束亚麻荠发展的因素,并提出了相应的建议。  相似文献   

10.
N-fixing legume crops may be a good component of a general plan to improve cropping system efficiency. For this purpose, crop suitability to specific environments must be established. To estimate the yield potential we examined the growth and yield response of faba bean (Vicia faba L.) crops to different thermal and photoperiod regimes. Irrigated field experiments were conducted in northwest Spain for 3 years (2004–2007) with cv. ‘Alameda’ sown on five different dates in each year from mid-autumn to mid-spring. Environmental conditions experienced by plants across sowing dates were largely different. Sowing date had a great influence on biomass, grain yield and its components. This effect was associated with changes in PAR captured, PAR use efficiency (PUE) and biomass allocation to the different organs. Critical leaf area index (LAIcr) tended to increase and the extinction coefficient, k, to decrease as the sowing date was delayed. Earlier sowing dates intercepted more radiation over the whole season than the spring sowing dates. Greatest crop growth treatments (2nd and 3rd sowing dates) had the highest values of PAR use efficiency probably due to more adequate temperatures for photosynthesis and a large number of reproductive sinks. The highest grain yield (7733 kg ha−1) was obtained with the mid-February sowing date, which produced the most pods and seeds per m2, the largest harvest index (62.0%), and large maximum leaf area index (5.41). Low yields of mid-autumn (1st) and mid-spring (5th) sowing dates were associated with reduced pods and seeds per m2. Temperature and photoperiod had a large impact on faba bean growth, development, and yield. Best yields were obtained when abundant assimilate supply and moderate temperatures were available during pod set.  相似文献   

11.
Downy mildew of field pea (Pisum sativum) caused by Peronospora viciae f. sp. pisi has become widespread in the main field pea production areas of central Alberta. Field experiments were conducted at naturally-infested field sites over several years to assess the effect of seeding depth, seeding date, seed treatment and foliar fungicides on downy mildew incidence and severity, and to estimate the relationship between severity and yield loss. Downy mildew was shown to cause substantial yield loss on field pea. Even a moderately severe infestation reduced pod numbers by 65% and seed yield by 75%. The loss (pod number or seed yield) was best explained by a linear model (y = −2.3114x + 10.086; R2 = 0.9441 and y = −2.5165x + 10.378; R2 = 0.9533, respectively). Depth of seeding (range 3–7 cm) did not affect downy mildew. Similarly, seeding date (early, mid and late May) did not have a consistent effect on disease levels. Late seeding occasionally reduced downy mildew, but always resulted in low seed yield. Several seed treatment fungicides reduced downy mildew, and metalaxyl-based products produced the highest yield. Several foliar-applied fungicides, including pyraclostrobin, azoxystrobin and metalaxyl, reduced downy mildew severity, but the results were not consistent across years. We conclude that cultural practices may not be sufficient for effective management of downy mildew, and that metalaxyl-based fungicides applied as seed treatments or foliar sprays could represent the best control option until downy mildew resistant pea cultivars become available.  相似文献   

12.
Camelina (Camelina sativa), guayule (Parthenium argentatum), lesquerella (Physaria fendleri), and vernonia (Centrapalus pauciflorus [formerly Vernonia galamensis]) are either under limited commercial production or being developed for production in the southwestern USA. Insect pests are a potential economic threat to all these new crops, with Lygus hesperus, the western tarnished plant bug, among the most prominent due to its regional abundance and propensity to feed on reproductive plant tissue. The objectives of this study were to establish baseline data on the feeding behavior and potential impact of L. hesperus on camelina, guayule, lesquerella and vernonia. Behavioral observations of adult females and males, and nymphs of this insect were made in the laboratory. Insects spent ≈35% of their time either probing (=tasting) or feeding on various reproductive and vegetative tissues of guayule, lesquerella or vernonia, but only 20% on camelina. When insects did probe and feed they preferred reproductive tissues, primarily flowers and siliques/achenes, and there were differences in these behaviors relative to crop but not generally to insect stage or sex. Insects probed and fed more on flower tissue of guayule and vernonia compared with camelina and lesquerella, and more on siliques of lesquerella compared with achenes of vernonia. When probing and feeding on vegetative tissue, there was generally a preference for stems compared with leaves in all crops except guayule. Results show that L. hesperus will readily feed on the economically important tissues of all crops, and although research has shown that this feeding did not consistently affect lesquerella yield, further work will be needed to determine if such feeding poses a risk to commercial production of camelina, guayule or vernonia.  相似文献   

13.
深松与播期对玉米冠层结构及产量性状的影响   总被引:2,自引:1,他引:1  
通过深松和播期对玉米冠层结构的调控,分析深松与旋耕条件下不同播期群体冠层结构特点,明确塑造高产群体冠层结构的耕作方式及适宜播期。采用裂区设计,主区耕法设2个水平(深松与旋耕),副区播期设3个水平(4月25日、5月10日和5月25日),研究深松与不同播期对玉米冠层结构及产量性状的影响。结果表明,深松可适当延长玉米生育进程,对玉米植株形态、叶面积指数(LAI)、群体光合势(LAD)、干物质积累特征参数及产量的影响均表现为深松>旋耕(CK);播期处理间其冠层结构、产量及产量构成因素存在显著差异,表现为早播>中播>晚播;随着播期推迟,早播(4月25日)产量较5月10日、5月25日分别提高3.61%和43.38%。说明深松条件下早播利于群体形成合理的冠层结构,可有效提高玉米产量。  相似文献   

14.
以紫米稻品种粮田紫1号为材料,在长沙地区比较研究了5个播期条件下紫米稻的产量与稻米品质。结果表明,粮田紫1号全生育期随播期推迟而明显缩短;有效穗数、每穗粒数、结实率与产量均随播栽期推迟而显著提高,5月31日播种处理产量达4 693.0 kg/hm~2;播期对粮田紫1号稻米品质有显著影响,碾米品质以5月11日播种处理最好,5月21日播种处理次之,稻米直链淀粉含量、粗蛋白含量与Se含量以5月21日播种处理最高,稻米Zn含量以5月31日播种处理最高。综合来看,粮田紫1号在长沙地区高产优质栽培的最佳播期为5月21-31日。  相似文献   

15.
The implications of adopting alternative seeding methods for rice and wheat establishment were examined at three geographically separate sites in the rice-wheat system of the Indo-Gangetic plains, across northern India. Rice yields in cultivated plots, established by either wet or dry seeding methods, were evaluated in comparison to yields from zero-tillage plots and under conventional transplanting methods. In the same trials, the effects of crop establishment methods in wheat were assessed both on wheat yields and rice yields. Rice crop establishment methods markedly influenced the emerging weed flora and attainable yields were measured in relation to intensity of weed management. Over four years, average rice grain yields in the absence of weed competition were greatest (6.56 t ha−1) under wet seeding (sowing pre-germinated rice seed on puddled soil), and similar to those from transplanted rice (6.17 t ha−1) into puddled soil, and dry seeded rice after dry soil tillage (6.15 t ha−1). Lowest yields were observed from dry seeded rice sown without tillage (5.44 t ha−1). Rice yield losses due to uncontrolled weed growth were least in transplanted rice (12%) but otherwise large (c. 85%) where rice had been sown to dry cultivated fields or to puddled soil, rising to 98% in dry seeded rice sown without soil tillage. Weed competition reduced multiple rice yield components, and weed biomass in wet seeded rice was six-fold greater that in rice transplanted into puddled soil and twice as much again in dry seeded rice sown either after dry tillage or without tillage. Wheat grain yields were significantly higher from crops sown into tilled soil (3.89 t ha−1) than those sown without tillage (3.51 t ha−1), and also were elevated (5% on average) where the soil had been dry cultivated in preparation for the previous rice crops rather than puddled. The method of wheat cultivation did not influence rice yield. Soil infiltration rates in the wheat season were least where the land had been puddled for rice (1.52 mm h−1), and greater where the soil had been dry-tilled (2.63 mm h−1) and greatest after zero-tillage (3.54 mm h−1).These studies demonstrated at research managed sites across a wide geographic area, and on farmers’ fields, that yields of dry seeded rice sown after dry cultivation of soil were broadly comparable with those of transplanted rice, providing weed competition was absent. These results support the proposition that direct seeding of rice could provide an alternative to the conventional practice of transplanting, and help address rising costs and threats to sustainability in the rice-wheat rotation. Further, analysis of patterns of long-term rainfall data indicated that farmers reliant on monsoon rainfall could prepare fields for dry direct seeded rice some 30 days before they could prepare fields for either transplanting or seeding with pre-germinated seed. Dry, direct seeding of rice contributes a valuable component of an adaptive strategy to address monsoonal variability that also may advance the time of wheat establishment and yield. Whilst the results illustrate the robustness, feasibility and significant potential of direct seeded rice, they also highlight the critical nature of effective weed control in successful implementation of direct seeding systems for rice.  相似文献   

16.
以湖南农业大学油料作物研究所提供的湘杂优753为供试品种,分3个播期(晚稻收割前7 d、晚稻收割前3d和晚稻收割后板田撒播)和2种种子处理方式(用烯效唑处理和不用烯效唑处理)对稻田套播油菜的产量及其产量结构进行了研究。结果表明:播种时间和种子处理方式对套播油菜产量均有显著影响,水稻套种油菜以烯效唑浸种后晚稻收割前3d直播最好。  相似文献   

17.
【目的]为明确浙北稻区直播单晚水稻的适宜播期和播量提供理论参考。【方法】以常规中熟晚粳秀水09为试材,在桐乡市龙翔街道和乌镇针对不同播期和播量开展研究,分析播期和播量对生育特性、穗粒结构和产量的影响。[结果]不同播期和播量对苗峰出现期、齐穗期、成熟期以及株高、总叶龄均有明显影响。随着播期的推迟和播量的增加,有效穗数增加,每穗总粒数和实粒数显著减少,千粒重也略有降低,产量下降明显。[结论】秀水09作当地直播单晚栽培的最佳播期为5月底至6月初,最佳播量为30.0~37.5kg/hm^2。  相似文献   

18.
吉育606具有高产稳产、抗逆性强、适应性广等特点。2013年通过吉林省农作物品种审定委员会审定。一般4月下旬5月初播种,保苗16-18万株/hm2,其高产制种技术是选择适宜的制种基地,合理安排播期和行比,及时放蜂,安排有效隔离距离,严格去杂确保种子纯度等。  相似文献   

19.
Sweet sorghum (Sorghum bicolor (L.) Moench) is an annual crop currently being investigated for biofuel production in the arid southwest United States (U.S.). Sweet sorghum is an ideal candidate because it can be grown under reduced inputs (water, fertilizer) and responds more efficiently to stresses than traditional crops. Many varieties have been bred for high sugar, syrup, and forage production, but much biodiversity still remains to be utilized.Studies performed in 2006 and 2007 found that high biomass and percent juice extracted were the best predictors of potential ethanol yield per area. This investigation was undertaken to determine what effects planting dates have on overall sugar and predicted ethanol yields.Four varieties (Dale, M81E, Theis, and Topper) were planted in April, May, June, and July of 2008. They were harvested at physiological maturity, with dates ranging from August 26 to December 2. Biomass, juice weight, and Brix of the juice were recorded in the field. Samples were analyzed in the laboratory by High Performance Liquid Chromatography (HPLC) for fructose, glucose, and sucrose.Theoretical ethanol yields were calculated based on biomass, juice weight, and percent sugar. These were compared to actual yields obtained from laboratory-scale fermentations of the harvested juice, which ranged from 7.4% to 11.2% (58.1-88.6 g L−1). Since our predictive model uses the maximum conversion rate of sugar to ethanol and this was not reached in the lab, the predicted yields were always higher than the actual yields. However, the model can be a useful tool for estimating ethanol yield per area.Total sugars and predicted ethanol production were influenced by planting date, but the degree of the effects depended on the cultivar planted. Overall a May planting date at this location is preferable due to consistently higher values for the yield components analyzed, and Theis is not recommended due to its high susceptibility to heat. Sweet sorghum juice has been successfully fermented into ethanol, which indicates this crop may be able to play a transitory role in the emerging biofuel market.  相似文献   

20.
播期和播量对滴灌冬小麦群体性状及产量的影响   总被引:4,自引:0,他引:4  
为了给滴灌冬小麦种植选择适宜的播期和播量组合, 以两个冬小麦品种新冬22号和新冬27号为材料,设置2个播期(9月27日和10月7日)和3个播量(150、225和300 kg·hm-2),通过大田裂区试验研究了播期和播量对滴灌冬小麦的群体性状、产量以及产量构成的影响。结果表明,冬前总茎数、返青后总茎数、成熟期收获穗数和主茎穗比重均随播量的增大而增加,且不同播量间差异显著;播期推迟,出苗数、冬前总茎数和返青后总茎数均降低。各处理均在孕穗期叶面积指数达到最大,且孕穗后10月7日播种的冬小麦叶面积指数下降比较慢。适当晚播有利于花后同化物和花前贮藏同化物在花后向籽粒的转运。播期和播量对滴灌冬小麦产量及其构成影响显著性,在10月7日播种、播种量为225 kg·hm-2处理下产量达到最高。  相似文献   

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