Yield Variation of Soybeans in Hawaii

In Hawaii, soybeans planted in November through January will produce yields of 25 to 50 percent compared with those planted through June. Yield components were studied for several soybean cultivars to determine which one was the most sensitive to planting dates and if there were differences between cultivars.
Soybean cultivars, Amsoy 71, Davis, Forrest, Kahala, P.I. 297,550 , and Williams were planted each month for two years. One November planting was lost, so there were 23 tests representing different environments. Each test consisted of 24 plots, six cultivars in four replications in a randomized block.
Analysis of variance of combined tests indicated significant differences between number of plants, pods per plant, seeds per pod, seed weight, yield of seed, plant height, and oil content of the seed that were due to data of planting, cultivar, and date × cultivar interaction.
Regression analysis indicated a closer relationship between pods per plant and yield during stress conditions (November through January plantings), whereas number of seeds per pod was more closely associated with yield during non-stress environments (April through June plantings).     

Response of confection sunflower (Helianthus annuus L.) grown in a semi‐arid environment to planting date and early termination of irrigation

Adjustments on planting date and on the time to terminate irrigation may reduce agricultural water use. However, such management practices in regions with extreme weather conditions have the potential to negatively affect yield. A 3‐year (2012–2014) study was conducted on a clay‐loam soil in a cool, semi‐arid environment to (i) determine the response of confection sunflower to planting date and irrigation termination timing and (ii) identify the relative importance of yield components in irrigated confection sunflower across planting dates. Early May planting had considerable negative effects on all studied variables, except on the percentage of large seeds. The highest yield of total and large seeds was obtained from the late May plantings, averaging 3,777 and 3,379 kg/ha, respectively. None of the irrigation strategies affected the measured variables. However, the interaction between planting date and termination of irrigation significantly affected the 1,000‐seed weight. Our study revealed the last week of May as suitable planting period for confection sunflower in the semi‐arid north‐western region of Wyoming, USA, and that irrigation on heavy soils may be terminated as early as at R5.5 stage without a significant yield reduction. The path‐coefficient analysis indicated head diameter and the number of seeds per head as important traits that significantly influence the yield of confection sunflower across planting dates.     

Effect of Soil Hydrothermal Regimes on the Performance of Safflower Planted on Different Dates

Soil hydrothermal regimes which can enhance seed germination, seedling emergence and development so that the late planted safflower (Carthamus tinctorius L.) can be competitive in comparison to normally planted crop need to be studied and suitabily modified. Therefore, a split-plot held experiment was conducted in Vertisols during 1984–85 and 1985–86 post-rainy season to determine the influence of planting date (PD₁: Oct. 20; PD₂: Oct. 30; PD₃: Nov. 10; PD₄: Nov. 20; PD_s: Nov. 30; PD₆: Dec. 10; and PD₇: Dec. 20), irrigation (I₁: come-up irrigation and I₂: I₁+ branching stage) and straw-mulch (M₀: No mulch and M₁: paddy straw mulch at 10 t ha^-1) and the interaction on the growth and development of safflower (Cultivar, JSF-7). Germination of safflower commenced earlier in October planting, but it was significantly higher in November and December plantings. Initiation of emergence and completion of germination required 153 and 307 cumulative degree days (CDD soil), respectively. Days to maturity decreased from 163 to 140 in 1984–85 and from 156 to 137 in 1985–86 with delay in planting from October to December. Height, number of branches, number of capsules, seed yield per plant and 1000 seed weight were significantly affected by the different treatments. Planting of safflower on October 30 and November 10 in both the seasons produced significantly higher seed yield than the other plantings. Branching stage irrigation (I₂) and straw mulching significantly improved all the yield attributes and seed yield of safflower in both the seasons. The water use efficiency (WUE) was higher in early plantings than in the later plantings. Higher WUE was obtained under come-up irrigation. Straw mulching increased the WUE, moderated the diurnal variations in soil temperature and provided a better thermostable regime more congenial for plant roots which resulted in increased safflower seed yield.     

Genetic analysis of yield and related traits in sunflower (Helianthus annuus L.) in dryland and irrigated environments

The definition of a suitable breeding strategy in drought-prone environments is an important task for sunflower breeders. To achieve this task, reliable information on heritability and gene effects on yield and related traits under these conditions is necessary. Thirty six sunflower hybrids were produced by factorial cross of six male-sterile and six restorer lines. Parents and their hybrids were evaluated in eight environments. Six environments consisted of two adjacent trials in the experimental area, the first under irrigation and the second under dryland conditions, during 1987, 1988 and 1992. The other environments were: one early planting trial in dryland conditions, conducted during 1987, and a winter trial planted in January during 1988. Estimates of female variance (σ_f) were significant for seeds per head, seed weight, head sterile center, days to blooming and oil content. Female × male interactions (σ² _fm) were significant for all characters except harvest index and index of susceptibility to drought. Estimates of narrow sense heritabilities, calculated with information from analyses combined across environments, were 0.65 for yield, 0.80 for seeds per head, 0.84 for seed weight, 0.81 for head diameter, 0.60 for sterile head center, 0.72 for oil content, 0.61 for harvest index, 0.72 for biomass, 0.94 for days to bloom, and 0.42 for drought susceptibility index. Heritability estimates for individual environments showed more variation for yield than for other traits. Estimates for heritability of canopy temperature were high (0.68–0.79). Rainfed yield was positively correlated with yield components and negatively correlated with canopy temperature and susceptibility index. It is concluded that an efficient breeding strategy for sunflower under moderate drought-stressed conditions is the simultaneous selection for seed yield in both rainfed and irrigated environments together with selection for canopy temperature and stem diameter. This revised version was published online in July 2006 with corrections to the Cover Date.     

Efficiency of water use of early plantings of sunflower

Rain fed crop production in Mediterranean environments depends to a large extent on strategies that avoid the intense summer drought. Early plantings of sunflower have given consistently higher yields in such environments, but the basis for such yield increases has not been explored. We conducted two field experiments at Cordoba (Spain) to investigate the effects of an early and a late planting date on the components of water-limited crop productivity; namely, water use (T), water use efficiency (TE) and harvest index (HI) of sunflower. The results were generalized by simulating rain fed sunflower yields, under early (1 January) and late (15 March) plantings, for a 25-year period with the aid of a simulation model of the Ceres type (OILCROP-SUN) which has been validated in Cordoba. Experimental seed yields of early plantings in 1989 and 1996 were 2.0 and 3.0 t ha⁻¹, while late plantings yields were 1.3 and 2.4 t ha⁻¹, for the 2 years. Average simulated yields were 2.7 ± 1.1 and 1.9 ± 0.7 t ha⁻¹ for early and late plantings, respectively. For the 2 years, T of early plantings was higher than that of late plantings, but the response of TE and HI to planting date was not the same in the two experiments. In the simulation exercise, T and TE of early plantings were consistently higher than those of late plantings, while there were no differences in the HI for the two planting dates. We conclude that early plantings of sunflower increase rain fed yields by increasing both T and TE, while the impact of planting date on HI very much depends on the crop water stress pattern, which is quite variable from year to year even in the predictable Mediterranean environment.     

内蒙古中西部小麦茬复种油用向日葵两熟制种植模式研究

试验于1999—2001年在内蒙古中西部地区的呼和浩特市初步研究了麦茬复栽油用向日葵种植模式。研究结果表明：该地区适宜的油用向日葵移栽育苗时间是在6月25日前后，叶龄为8片展开叶，株高为40—50cm；较适宜油用向日葵品种为新葵杂四号，其次是KWS；复栽油用向日葵的单产可达到2820—3570kg／hm^2。综合成本分析表明，麦茬后复栽油用向日葵种植模式比小麦单作经济效益提高101．81％，较单作油用向日葵提高63．92％。     

播种期对2个不同类型棉花品种产量和产量构成的影响

 适期播种是棉花丰产的重要措施,品种类型常影响播种期。为确定不同类型棉花品种的适宜播期,采用裂区设计,以品种类型（早发型鲁棉研21号和后发型鲁棉研28号）为主区,播种期（4月上旬早播、4月下旬中播和5月上旬晚播）为副区,于2009—2010年在山东临清研究了品种类型和播种期对棉花产量和产量构成的影响。两年的试验结果表明：品种和播期对棉花产量有显著的互作效应,而且主要是由于铃数和衣分的变化所致;早发型品种4月下旬播种产量最高,比4月中旬播种增产6.3%,5月上旬播种与4月中旬播种产量相当;后发型品种4月中旬播种产量最高,比4月下旬和5月上旬播种分别增产4.8%和12%。在鲁西北棉区地膜覆盖栽培条件下,早发型品种以4月下旬播种为宜,可以适当晚播,直到5月上旬;后发型品种应适当早播,以4月中旬为宜,晚播会显著减产。     

Effects of Temperature and Photoperiod on Days to Flowering, Yield and Yield Components of Lupinus albus (L.) under Field Conditions

A better understanding of the agronomic importance of planting date and the influence of cold temperatures and photoperiod during germination and plant growth may lead to better management strategies for cultivation of the sweet white lupin (Lupinus albus). The effects of planting date (temperature and photoperiod) were determined on the number of days to flowering, yield and yield components of four early to medium and one late sweet white lupin genotype in a field trial at Potchefstroom, South Africa, planted during February 1996 to January 1997. Moisture stress was avoided through regular irrigation. Duration of the developmental phases planting date to emergence, emergence to floral initiation, initiation to first flower, duration of flower and days to physiological and harvest maturity was related to field measurements of temperature and photoperiod. Differences in the main determinants of yield, i.e. seeds per pod, pods per plant, single seed mass (SSM), plant and pod height and yield, were measured. Results showed that both temperature and photoperiod influence the growth and development of the Lupinus albus genotypes ‘Esta’, ‘Hantie’, ‘Tifwhite’, ‘Kiev’ and ‘LAL 186’. Temperature influences include the effect of vernalization at seedling emergence. Minimum grass temperatures under 5 °C at emergence are effective for vernalization. However, after grass temperatures at emergence increased again from June to December, to gether with an increase in the photoperiod length, ‘Tifwhite’ as well as the other genotypes still flowered earlier, confirming that these cultivars are long‐day plants, which is in accordance with controlled‐environment data. Cool vernalizing temperatures thus not only influence obligate vernalization requiring genotypes such as ‘Tifwhite’, but also influence the non‐obligate genotypes studied. Plan‐ting date had a significant influence on pods per plant, single seed mass (SSM) and seed yield. In all trials laterplanting, from June to November, decreased SSM and seed yield. The highest seed yield of 1.5 t ha^?1 was obtained for the 10 June planting date and the lowest average yield of 0.450 t ha^?1 for the 5 November planting date.     

冀北油葵主要栽培因素对产量的影响

为了研究主要栽培因素对油葵产量的影响,确定冀北地区油葵最优栽培方案.本研究采用5因子二次回归正交旋转组合设计,建立播期、密度、氮肥、磷肥和钾肥与油葵产量的效应函数.结果 表明,播期、密度、氮肥、磷肥和钾肥随着投入量的增加油葵产量呈先升高后下降趋势,其中播期、播期氮肥互作起着重要的作用.目标产量大于2916.67 kg/...     

播期、密度和氮肥运筹对高产品种-淮麦33产量和品质的调控

为了明确高产小麦品种淮麦33优质、高产、高效栽培的群体调控和氮肥管理策略,以淮麦33为材料,研究了播期、密度、施氮水平和基追比对其籽粒产量和品质的影响。结果表明,播期和密度对淮麦33的籽粒产量均有显著影响。5个播期中,10月11日播种的籽粒产量最高,10月1日、10月21日亦可以取得较高产量,10月31日播种产量明显下降,11月10日播种产量下降最多。密度为225万?hm-2时产量最高。蛋白质含量也随着密度的增加和播期的推迟呈上升趋势。同时,增加氮肥用量和后期施肥比例不仅可以提高淮麦33产量,亦可以增加蛋白质含量、湿面筋含量和沉淀值。综合分析,在本试验条件下,10月11日播种、225万?hm-2基本苗、施氮量300 kg?hm-2,氮肥运筹5:3:2时淮麦33产量最高,品质最好。     

Effect of Date of Planting, Genotype and Source of Seed on Disease Incidence, Yield, and Agronomic Performance of Soybean

Four soybean genotypes chosen from four seed sources were planted in a factorial arrangement on four dates in a split-plot design at the Alabama A & M Experimental Station on a Decatur silt clay loam soil. The highest vigor index was recorded from seeds harvested from the 4th date of planting. These seeds had the lowest level of Diaporthe phaseolorum var. caulivora infection, indicating that vigor index, as a measurement of seed quality, was negatively correlated with the level of infection by soybean stem canker pathogen. Seed yield was highest at the 2nd date of planting and lowest at the 4th date of planting. Tracy-M and Bedford confirmed previous reports on their resistance and susceptibility, respectively, to soybean stem canker. All the genotypes performed their best at the 2nd date of planting. Source of seeds appeared to have little effect on the performance of the plant in the field.     

Factors Associated with Reduced Yields of Delayed Plantings of Soybean1

Field experiments were conducted for four years (1981 to 1984) at Lexington, KY, USA (38° N latitude) to determine the causes of reduced yields associated with delayed plantings of soybean (Glycine max [L.] Merrill). Five cultivars were planted in mid-May and early July in row spacings ranging from 18 to 89 cm and the plots were irrigated to minimize moisture stress. Yields were significantly reduced by delayed planting because of reductions in the number of seed m^?2 and mass seed^?1. The yield reduction under irrigation indicates that moisture stress is not a major cause of reduced yields from delayed plantings. The reductions in seed number were associated with lower insolation interception during flowering and pod set and with smaller vegetative mass (g m^?2) at growth stage R5 (beginning seed fill). The data suggest that a vegetative mass at R5 greater than that required to intercept 90 % or more of incident insolation is required to maximize seed number. The length of the seed filling period was not affected by planting date. Mass seed^?1 was positively related to mean air temperature during seed filling, which suggests that the smaller seed from delayed plantings are a result of the lower temperatures associated with the later maturity.     

Path-coefficient analysis of some yield components of sunflower (Helianthus annuus L.), I

Summary Interactions of seven bio-morphological characteristics of sunflower (head diameter, number of flowers per head, number of seeds per head, 1,000-seed weight, volume weight, kernel content in seed, oil content) and their correlations with seed yield per plant were examined. The path-coefficient analysis provided information about direct and indirect effects of the examined characteristics on seed yield per plant. The correlation coefficients were positive and highly significant. The highest direct positive effect on seed yield per plant was exhibited by the weight of 1,000 seeds. Head diameter, volume weight and kernel content had a direct negative effect on seed yield per plant.     

苏中地区稻茬小麦生产措施采用特征与效益调研分析

为进一步明确江苏苏中地区小麦生产情况,通过发放问卷调查表的形式,获取了代表苏中的兴化和高邮两市2016—2020年度小麦生产调研数据,明确了该区域从事小麦生产的农户以51～60岁中老年劳动者为主,农户受教育程度以初中为主,迫切需要农业新技术,但接受能力偏低。不同农户田间小麦播期、播种量和肥料施用量均有明显差异。在10月26日—11月5日播种,采用211～240 kg/hm²的播种量易获得高产。两地农户平均施氮水平分别为308 kg/hm²和281 kg/hm²,部分农户施氮量高于350 kg/hm²时,产量不增反减。在播期、播量和施氮量作用下,兴化和高邮市小麦平均产量分别为6129.64 kg/hm²和6788.25 kg/hm²,农户间高产水平与低产水平间的产量差值分别为2270.36 kg/hm²、1611.75 kg/hm²。不同种麦规模获得的经济效益不同,种植面积为6.67～20 hm²     

海南冬季棉花生育期分析

采用124个陆地棉品种(系),于2004-2005年冬季在海南岛三亚进行了4个播期的自然生育期试验。结果显示,全生育期平均为132.75 d,与我国主产棉区相差不大。不同播期之间全生育期相差较明显,以10月1-2日的第一播期最短,11月16-20日的第三播期最长,两者相差约15 d。冬繁棉花,早熟与中熟品种的全生育期相差不大(不到5 d),与棉区差异悬殊。就是在12月初播种,两个熟性的品种在4月中旬都能够完成自然生育期。根据试验结果,作者提出了冬繁棉花的“凹型生长模式”,并发现在后期播种的各个生育阶段,生育期的调节存在“缓冲”或“补偿”作用。根据凹型模式,作者提出科研南繁和产业南繁最佳播种期是10月,而抢季南繁在12月初播种亦可成功,并认为控制生育期的关键是在生长速度“低谷”时期。     

适期晚播对不同密度冬小麦产量和茎秆抗倒性能的调控效应

(方法)本试验在宽幅播种条件下,以大穗型冬小麦品种泰农18为材料,设计常规播期10月10日和适期晚播10月20日2个播期处理,各播期下分别设置225、375和525万/公顷3个种植密度,(目的)研究了播期和密度互作对冬小麦产量及产量形成、茎秆重心高度、基部节间机械强度和茎秆抗倒指数的影响,以期明确适期晚播对密植高产冬小麦产量和茎秆抗倒性能的调控效应。(结果)研究结果表明,播期和种植密度显著影响冬小麦的产量和抗倒性能。各播期间适度密植(375万/公顷)可通过提高穗数获得高产,且在两播期间无显著差异。适度晚播显著提高各密度冬小麦抗倒指数;在晚播条件下,随种植密度增加,小麦重心高度提高的幅度、基部节间机械强度降低的幅度显著低于常规播期,从而使得适期晚播密植小麦的抗倒能力仍可维持在较高水平。(结论)适度密植小麦可通过适期晚播平衡其产量和抗倒能力,本试验条件下,采用375万/公顷的种植密度,在10月20日播种,可协同实现高产、稳产。     

Foliar Application of Glycinebetaine and Salicylic Acid Improves Growth,Yield and Water Productivity of Hybrid Sunflower Planted by Different Sowing Methods

Improved planting methods and foliar application of glycinebetaine (GB) and salicylic acid (SA) can improve the water productivity in field crops under limited water supply conditions. A 2‐year field study was conducted to evaluate the possible role of different planting methods and foliar applications of GB and SA in improving the yield, quality and water productivity of hybrid sunflower (Helianthus annuus L.). The crop was planted by flat sowing (75 cm spaced rows) and ridge sowing (75 cm spaced ridges), with GB and SA applied exogenously at 100 and 0.724 mm , respectively, at both budding and flowering stages, while control plots received distilled water. Ridge sowing, rather than flat sowing, improved the biological yield, oil yield, leaf area index (LAI), crop growth rate (CGR), plant height, water‐use efficiency and final achene yield during both the years. Foliar applications of GB and SA at both the stages improved the achene yield, although foliar application of GB at flowering was the most effective. Neither the planting methods nor the foliar application of GB and SA altered the achene oil contents during both the years. Foliar application of GB and SA increased the free proline content of the leaf and GB contents at flowering but reduced the achene protein contents, whereas planting method had no effect on these attributes across the years. Of the foliar applied chemicals, GB was more effective in improving sunflower growth and yield and water productivity than SA. To conclude, ridge sowing coupled with foliar application of GB at flowering stage could be beneficial for achieving maximum yields of hybrid sunflower under relatively water limited conditions in the field.     

Growth and Yields of Intercropped Sorghum and Sunflower (Helianthus annuus L.) in Semi-arid Nigeria

Effect of five planting patterns on the growth, yield and yield components of intercropped sunflower and sorghum was studied during 1989–90 planting seasons at University of Maiduguri, Nigeria. Generally, intercropping depressed the performance of sorghum more than sunflower. Sorghum plants grown in alternate hills with sunflower had the shortest stems, the least dry matter and total seed yields per hectare, while the highest dry matter and seed yields were obtained from sorghum planted in five alternating rows with sunflower. Similarly, in sunflower, plants grown in five alternating rows with sorghum had the highest yields compared with other planting patterns, but there were no significant differences in the dry matter and total seed yields of sorghum and sunflower intercropped in three and five alternating rows. Light transmission, leaf area index and yields of both crops followed similar trends under the various planting patterns. Interplanting in five alternating rows that allowed the highest leaf area also allowed the lowest light transmission and produced the highest yields. Land use efficiency was highly improved under three and five rows interplanting by 52 and 74 % respectively.     

CIMMYT和中国硬质春麦在4种CIMMYT不同处理环境中产量和蛋白品质性状分析

灌溉、播期和垄作等栽培方式对小麦产量和蛋白品质性状具有重要影响。将21个中国和CIMMYT硬质春麦品种于2000—2001和2001—2002年度分别种植在CIMMYT的Obregon试验站4种处理环境中。结果表明，所有性状均受品种和处理环境的显著影响，产量和沉降值同时还受品种和处理环境互作效应的显著作用，在进行产量和品质改良时应考虑品种与处理环境间的互作。充分灌溉和适期播种有利于提高产量，减少灌溉迟播垄作则有利于提高蛋白含量和沉降值。Rayon F 89产量、蛋白含量和沉降值均较高；龙麦26产量、蛋白含量和沉降值显著高于其他光敏感品种。充分灌溉适期播种垄作利于提高Rayon F 89等的产量和Weaver等的沉降值，充分灌溉适期播种平播利于提高Seri M 82等的产量和Attila等的沉降值，充分灌溉迟播垄作利于提高龙麦26等的产量和Super Seri#1等的沉降值，减少灌溉适期播种垄作则利于提高Rayong F 89等的产量和Weaver等的沉降值。     

Influence of Seasonality on Certain Leaf Characteristics in Rice Cultivars

Higher growth and grain yield in rice was obtained in February planting as compared to July and October plantings. This was achieved through favourable leaf characteristics. In all the three plantings, leaf number monitored the leaf area rather than ILS which showed minimal alterations by the seasonality. There was a considerable variation in the attainment of critical leaf area index (LAI) among cultivars in different seasons. Thus, attainment of critical LAI would be necessary to influence the sink strength positively.