多效唑对麦茬旱稻农艺性状影响及生理作用的研究

以早稻277为材料．在l叶l心期进行了不同浓度多效唑喷施试验。麦茬早稻苗期喷洒多效唑对植株高度有明显的降低作用．可提高秧苗素质和抗倒力。同对照相比．叶面喷施多效唑可使麦茬早稻产量增加10％左右。增产的生理作用主要表现在光合速率提高，气孔导度和蒸腾速率提高。叶面喷施多效唑可增加麦茬早稻的穗粒数。     

水稻不同播量对秧苗素质及产量的影响

用小区试验的方法，研究了水稻不同播量对秧苗素质及产量的影响，结果表明：水稻旱育苗播种芽200～750g/m^2，随着播种量的增加，叶龄、根数、地上干重、分蘖率、成苗率明显下降，产量逐渐降低。现有的生产条件，最佳播种量应为200～250g/m^2，育出的秧苗壮，水稻产量高，应在生产上推广应用。     

水稻不同播量对秧苗素质及产量的影响

用小区试验的方法,研究了水稻不同播量对秧苗素质及产量的影响,结果表明:水稻旱育苗播种芽200～750gm/2,随着播种量的增加,叶龄、根数、地上干重、分蘖率、成苗率明显下降,产量逐渐降低。现有的生产条件,最佳播种量应为200～250gm/2,育出的秧苗壮,水稻产量高,应在生产上推广应用。     

不同播量对机械精量直播水稻产量及其物质生产的影响

以杂交晚粳稻甬优8号、常规粳稻武运粳19为材料,在机械化精量直播方式下,研究了不同播量对其产量及物质生产的影响。结果表明,每667 m2播种量甬优8号1.5~2.2 kg、武运粳19号2.2~3.0 kg处理的产量最高;其群体均能于有效分蘖临界叶龄期够苗,拔节期达高峰苗,且数量适宜,最终成穗率较高(75%左右);最大叶面积指数均出现在孕穗期,数值适宜;抽穗后干物质积累多,成熟期生物学产量高。     

播期对麦茬大豆生长发育特点及产量形成规律的影响

探讨了播期对麦茬复种大豆生长发育特点和产量构成各因素的影响。结果表明,在栽培条件相同的情况下,除受品种本身丰产潜力等因素影响外,播种期的早晚是影响麦茬大豆产量的主要因素。要想提高春麦区麦茬复种大豆产量和品质,必须抢时早播,为创造高产提供较充余的生育时间。     

春稻和麦茬稻产量构成因素及产量的比较

以天津市培育的优质小站稻品种津川1号和隆优619为供试材料,分析了春稻和麦茬稻产量构成因素和产量的差异.结果表明,津川1号麦茬稻的有效穗和千粒重明显低于春稻,而穗粒数间不存在显著差异;隆优619除春稻的千粒重显著高于麦茬稻外有效穗和穗粒数方面不存在显著差异.从实际产量的数值来看,津川1号和隆优61...     

不同播期对荞麦产量因素的影响

荞麦分甜荞和苦荞,属于小宗粮食作物.荞麦营养丰富,其蛋白质、脂肪和维生素等含量高于水稻、玉米、小麦等大宗粮食作物,还含有禾谷类粮食作物所不具有的芦丁和叶绿素.荞麦还是良好的药用作物,具有降血脂、降低胆固醇的功效,对糖尿病、高血压、慢性胃炎等有一定的疗效,能够增强机体免疫力、起到抗炎防癌的作用.随着科技的进步、人民生活水平的提高和对营养、保健品需求意识的增强.荞麦将成为21世纪人们的重要食品和保健佳品.辽宁省传统上习惯在立秋后播种荞麦,单产水平较低,严重影响荞麦的发展和种植面积的扩大.本文就选择荞麦的适宜播期,提高荞麦产量方面做些探索,以促进荞麦生产的发展,增加农民的经济收入.     

水分胁迫对节水抗旱稻产量形成和根系形态生理特性的影响

目的 探究节水抗旱稻组合旱优73在不同灌溉条件下产量形成特点及其根系形态生理的变化情况。方法 以节水抗旱稻旱优73和高产水稻H优518为材料,通过根管试验设置三种水分处理(常规灌溉、轻度水分胁迫、重度水分胁迫),调查株高、分蘖、根系形态特征和生理特性以及产量构成因素,分析性状之间的关系,探究不同程度水分胁迫对旱优73和H优518产量形成和根系形态生理的影响及其差异。结果 两年的重复试验结果表明,与常规灌溉相比,在轻度水分胁迫下,旱优73的产量及其构成因素无显著变化,H优518的产量在两年内平均减少了25.6%,每穗粒数、结实率、千粒重也显著降低;在重度水分胁迫下,两品种产量及其构成因素均显著降低,其中,旱优73的产量两年内平均减少了28.8%,H优518产量减少了46.1%。与常     

水分胁迫对节水抗旱稻产量形成和根系形态生理特性的影响

[目的]探究节水抗旱稻组合旱优73在不同灌溉条件下产量形成特点及其根系形态生理的变化情况.[方法]以节水抗旱稻旱优73和高产水稻H优518为材料,通过根管试验设置三种水分处理(常规灌溉、轻度水分胁迫、重度水分胁迫),调查株高、分蘖、根系形态特征和生理特性以及产量构成因素,分析性状之间的关系,探究不同程度水分胁迫对旱优7...     

不同播量与培养土对机插连晚秧苗素质和产量的影响

为探讨适宜连作晚稻机插秧标准化育秧技术,以天优华占和甬优9号为材料,采用田间试验方法,研究了5种不同培养土和3个播种量水平对连晚机插秧苗素质、栽插质量和产量的影响。结果表明,不同培养土和播种量培育出的秧苗素质不同,以播种量90 g/盘、基质或黄泥土+基质母剂作为床土更能培育出适合于机插的高素质秧苗,且实际产量较高。     

播期对大豆产量及农艺性状的影响

以引进和本地23个品种为材料,研究了在沧州气候条件下,不同播期对大豆产量及主要农艺性状的影响.结果表明:推迟播种,缩短了始花期至生理成熟期的天数,从而缩短了各品种的生育期;晚播严重降低了各品种的株高和主茎节数;产量、单株粒数、百粒重与播期达到了显著负相关,所以夏大豆适时早播意义重大.     

Integrated rodent management in outbreak-prone upland rice growing areas of Northern Laos

An integrated rodent management program was tested in outbreak-prone areas in three provinces of the Northern uplands of Laos (Luangprabang, Phongsaly, Houaphanh). In each province, it was replicated in six villages and associated upland rice fields; six neighboring villages served as negative controls. The program started end of 2010 and aimed at protecting the wet season rice harvest of 2011 against rodent damage. Rodent control techniques included sustained trapping, rodent-proofing of grain stores, rodent hunts and village sanitation campaigns, and biological rodent control using the protozoan parasite Sarcocystis singaporensis. The measures were embedded in a community approach, which was coordinated by provincial and district agricultural officers. Compared to the control villages, which showed on average 10.9% rat damage to ripening upland rice before harvest in 2011, and to the situation of the previous year (12.8%), rat damage was significantly reduced to an average of 4.3% in rice fields of the treatment villages. The incidence of rat-infested rice storage huts dropped significantly from an average of 86% in 2010 to 3.5% in 2011 in the treatment villages. Villagers from Houaphanh culled a total of 73,088 rodents over a period of about nine months, which included mainly black rats (Rattus rattus). Because the program phased out before harvest in 2011, potential losses due to rodents were predicted based on yield-damage relationships of the crop year 2010. The predicted average reduction of yield loss for 2011 was 55%, or 417.6 kg ha⁻¹, in the treatment villages when compared to the controls. The program implemented principles of ecologically-based rodent management (EBRM), the components of which are discussed. In conclusion, EBRM could be helpful in stemming as what was observed as high chronic rodent populations in the uplands of Laos. True outbreaks will require development of a suitable forecast system.     

播期和品种对沿淮晚播稻茬小麦产量和产值的影响

沿淮稻茬小麦播期推迟是生产面临的重大问题.为探究播期和品种对稻茬麦产量和产值的影响,2017-2019年度小麦生长季选用20个品种,按照裂区设计,设置10月30日、11月14日、11月29日3个播期,定量解析了播期、品种对小麦产量和产值的影响.结果表明,年度、播期、品种及品种和播期间互作对稻茬小麦产量、产值的影响均显著...     

Yield potential and water use efficiency of aerobic rice (Oryza sativa L.) in Japan

Intensive rice farming in aerobic soil, referred to herein as aerobic rice, can greatly reduce the water input compared to that of flooded rice cultivation. The objective of this study was to compare the potential productivity of aerobic rice and flooded rice using high-yielding varieties at two locations in Japan in two successive years. In aerobic fields, the total amount of water supplied (irrigation plus rainfall) was 800–1300 mm. The soil water potential at 20-cm depth averaged between −15 and −30 kPa each growing season, but frequently reached −60 kPa. The average yield under aerobic conditions was similar to or even higher than that achieved with flooded conditions (7.9 t ha⁻¹ in 2007 and 9.4 t ha⁻¹ in 2008 for aerobic versus 8.2 t ha⁻¹ for flooded). The average water productivity under aerobic conditions was 0.8–1.0 kg grain m⁻³ water, slightly higher than common values in the literature. The super-high-yielding cultivar Takanari achieved yields greater than 10 t ha⁻¹ with no yield penalty under aerobic conditions in 3 out of 4 experiments. The favorable agronomic characteristic of Takanari was its ample sink capacity (grain number × grain weight). In conclusion, high-productivity rice cultivation in aerobic soil is a promising technology for water conservation. With continued breeding, future aerobic rice varieties will possess large numbers of spikelets and sufficient adaptation to aerobic conditions such that they will consistently achieve yields comparable to the potential yield of flooded rice.     

Possible causes of yield failure in tropical aerobic rice

Aerobic rice is a water-saving rice production system for water-short environments with favorable soils and adapted, potentially high-yielding varieties that are direct dry seeded. Soils remain aerobic but supplementary irrigation is applied as necessary. In the dry season of 2004 and 2005, a water by N experiment was set up at the location “Dapdap” in central Central Luzon, Philippines, to explore water and N management strategies in aerobic rice. The experiment was laid out as a split-plot design on a loamy sand soil with three water treatments (irrigation twice per week, once per week, and once in two weeks with modifications) and 5 N levels (0–200 kg ha⁻¹). Average seasonal soil moisture tension ranged from 9.2 to 20 kPa but yield hardly responded to the treatment combinations and ranged from 0 to 2 t ha⁻¹. In addition to trial-specific parameters, root knot nematodes and micronutrients (2005) were monitored. Galling of roots due to nematodes was assessed through a rating scale of 0–5, with 0 = no galling and 5 = >75% of the root system galled. The degree of galling reached a level of 5 at flowering and harvest in 2004, and 3 at tillering and 4 at harvest in 2005. Results of a plant tissue analysis at mid-tillering for Fe, Mn, and Zn showed on average values above critical levels; individual replicates, however, indicated deficiencies for Mn. In addition to actual field observations, we used simulation modeling (ORYZA2000) as a tool to estimate attainable yield under actual water conditions and N inputs to explore how yield failure set in. Simulation results matched observed values for total above-ground biomass and leaf area index quite well when no N was applied. When high rates of N (200 and 165 kg ha⁻¹) were applied, simulated values matched actual field data only until about the panicle initiation stage; afterward, observed values remained below the simulation. We interpreted this as evidence that growth-limiting factors other than water or N affected the crop from this growth stage on. Observations made in the field on root knot nematodes and micronutrients suggested that these two factors, especially root knot nematodes, may have been major constraints to crop development in this experiment.     

Silicon fertilization modulates 2-acetyl-1-pyrroline content,yield formation and grain quality of aromatic rice

Present study aimed to assess silicon (Si) mediated yield, grain quality and regulations in 2-acetyl-1-pyrroline accumulation (2-AP) in aromatic rice. Four different levels of Si at 15, 30, 45 and 60 mg kg⁻¹ were applied to two aromatic rice cultivars i.e., Nongxiang 18 and Meixiangzhan 2, while pots without Si were served as control (CK). Results revealed that Si fertilization improved 2-AP, Si and proline contents in leaves and grains as well as activities of proline dehydrogenase (PRODH) and net photosynthetic rates (Pn) (in leaves) while interfered with total N contents in leaves and grains. Moreover, leaves N and proline contents, and net photosynthetic rates (Pn) were decreased with plant age i.e., tillering > flowering > maturity while PRODH activities and Si contents were highest at flowering and maturity stages, respectively and minimum at tillering stage. Furthermore, growth, yield and quality components were also improved by Si application but results were not consistent regarding grain quality for both rice cultivars. Further, Si contents in leaves have significant positive relations (r = 0.3974, P < 0.05) with grain 2-AP contents at flowering stage. Hence, Si proved better for both rice cultivars whereas 2-AP contents were higher for Meixiangzhan 2 than Nongxiang 18.     

Effects of planting date and variety on flooded rice production in the deepwater area of Thailand

Crop management plays an important role in the transition from a deepwater rice to a flooded rice production system but information about optimum management strategies are currently lacking. The goal of this study was to determine the effect of planting date and variety on flooded rice production in the deepwater area of Thailand. Two experiments were conducted at the Bang Taen His Majesty Private Development Project in 2009 and 2010 to represent conditions prior to flooding (early rainy season) and after flooding (dry season). The early rainy season crop covered the period from May to October 2009, while the dry season crop covered the period from November 2009 to April 2010. The experimental design was a split plot with four main plots and three sub plots replicated four times. The treatments for the main plot were various planting dates, while the treatments for the sub plots were rice varieties. The dates of the critical developmental phases of rice were recorded and biomass was sampled during the growing period. The collected data were statistically analyzed using ANOVA and treatment means were compared to identify the appropriate plating date and the best variety for the area. The highest average yield was obtained for variety PSL2 across transplanting dates from June 19 to July 23, with an average yield of 3898 kg ha⁻¹. The dry season crop showed that both biomass and yield were affected by the interaction between planting date and variety. The highest yield was obtained for variety PTT1 transplanted on November 9. The research showed that the variety PSL2 is the most suitable variety for early rainy season production with a transplanting date ranging from June 19 to July 23, while the variety PTT1 planted on November 9 was the best management practice for the dry season crop. However, a high yielding flooded rice variety that has a short growth duration is still needed for this area.     

Row spacing and weed control timing affect yield of aerobic rice

Field experiments were conducted during the wet season of 2009 and dry season of 2010 to determine the effects of row spacing and timing of weed control on weed growth and yield of aerobic rice. Ten weed management treatments were used to identify critical periods of weed competition with aerobic rice grown in three different row spacings (15-cm, 30-cm, and as paired rows 10-20-10-cm). Dominant weed species during both growing seasons were Rottboellia cochinchinensis, Digitaria ciliaris, Echinochloa colona, and Eleusine indica. Rice grown in 30-cm rows had greater weed biomass and less grain yield than in 15-cm and 10-20-10-cm rows; weed growth and grain yields were similar between 15-cm and 10-20-10-cm rows. Rice yields in the wet season ranged from 170 kg ha⁻¹ where weeds were not controlled throughout the crop duration to 2940 kg ha⁻¹ in weed-free treatment, indicating a 94% yield loss with uncontrolled weed growth. Similarly in the dry season, plots with no weed control (140 kg ha⁻¹) compared to weed-free plots (3640 kg ha⁻¹) indicate a 96% yield loss with no weed control. Gompertz and logistic equations were fitted to yield data resulting from increasing durations of weed control and weed interference, respectively. Critical periods for weed control in the wet season, to obtain 95% of a weed-free yield, were estimated as between 18 and 52 days after sowing (DAS) for crops in rows at 15-cm, 20-51 DAS at 10-20-10-cm, and 15-58 DAS at 30-cm. These intervals in the dry season were 17-56 DAS for crops in rows at 15-cm and 17-60 DAS at 10-20-10-cm and 15-64 DAS at 30-cm. Durations of the critical periods in the wet season were 31 days at 10-20-10-cm, 34 days at 15-cm and 43 days at 30-cm, while in the dry season, these were 43 days at 10-20-10-cm, 39 days at 15-cm and 49 days at 30-cm. In both seasons, crops in the wider spacing (30-cm) were vulnerable to weed competition for the longest period. The information gained from this study suggests that the aerobic rice yields better in 15-cm rows and 10-20-10-cm arrangements than in 30-cm rows and there is very little benefit of weed control beyond 8 weeks after sowing.