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1.
试验表明,杂交晚粳稻八优52在杭州市免耕直播栽培,6月初至6月中旬播种,播种越早,产量越高;播种量在19.5-25.5kg/hm^2范围内,播种量越少,产量越高。八优52在杭州市免耕直播栽培,播种期安排在6月上旬,播种量控制在19.5-22.5kg/hm^2为宜。  相似文献   

2.
播种期和播种方式对免耕直播油菜生长与产量的影响   总被引:12,自引:1,他引:12  
对一季稻田油菜免耕直播的播种期、播种量、播种方式、种子处理进行了研究.结果表明:水稻收割后,免耕直播油菜播期尽可能提早,播量以3 000~3 750 g/hm2为宜.随着播期的推迟,包衣种子免耕撒播后进行稻草覆盖的播种方式最佳.示范结果表明,不同栽培方式中,免耕直播油菜的产值和纯收入均超过翻耕直播和板田移栽的平均水平,且技术简便、省本、高产、高效,可减轻劳力紧张的矛盾,实用性强,发展前景广阔.  相似文献   

3.
油茬田免耕直播稻适宜播期和播量的研究   总被引:3,自引:4,他引:3  
敖和军  周桂清  贺勇  邹应斌 《作物研究》2004,18(3):151-153,158
2002~2003年在湖南省石门县开展了油茬田免耕直播稻的适宜播期和播种量的研究,探讨了3个播种期和3个播种量对两优培九的生育期、株高、总叶片数、出叶速度、茎蘖动态、产量和产量构成因素的影响.试验结果表明,两优培九作一季中稻免耕直播栽培,以5月中旬播种,播种量22.5 kg/hm2较适宜.  相似文献   

4.
杂交晚粳免耕直播栽培最佳播种期和播种量研究   总被引:9,自引:0,他引:9  
杂交晚粳作免耕直播栽培,播种期从5月25日到6月9日,播种越早,产量越高;播种量从18.75 kg/hm^2到11.25 kg/hm^2,播种量越低,产量越高。从本试验看,杂交晚粳嘉乐优2号在嘉兴南湖作免耕直播栽培,以5月25日播种、11.25 kg/hm^2播种量时产量最高,说明杂交晚粳在一定范围内必须早播、稀播,才能更好地发挥其分蘖强和穗型大等优势而获得高产。  相似文献   

5.
稻田油菜机械直播高产栽培技术研究初报   总被引:3,自引:1,他引:3  
娄政科 《作物研究》2004,18(2):105-105,107
以湘杂油5号为材料,用小型耕整机牵引"署华MLB-100型多功能播种机"进行稻田直播油菜试验.结果表明,用机械直播栽培油菜具有减轻劳动强度、降低生产成本、提高经济效益等优点.其高产栽培关键措施是:前作水稻开好丰产沟,适时播种,播种量3.75~4.5kg/hm2;精心操作,不漏播;利用直播机集中施足基肥,及时追肥,促冬发;化学除草;施用硼肥.  相似文献   

6.
油茬田免耕直播水稻施肥量的研究   总被引:2,自引:2,他引:0  
李娓  周桂清  贺勇 《作物研究》2005,19(1):9-10
2002~2003年在石门县进行了油茬田免耕直播水稻栽培试验,比较研究了5种不同施肥量对培两优93和两优培九的生育期、株高、总叶片数、茎蘖动态、产量和产量构成的影响.结果表明油茬田免耕直播水稻的适宜施肥量为750~900kg/hm2缓释肥.  相似文献   

7.
不同油菜秸秆还田量对免耕直播单季晚稻产量的影响   总被引:1,自引:0,他引:1  
2006年在浙江嘉兴开展了油菜秸秆还田免耕直播晚稻的试验。结果表明,在免耕直播单季晚稻上,油菜秸秆还田量1 800,3 600,5 400,7 200 kg/hm2,产量分别为9 100,9 275,9 375,9 325 kg/hm2,比对照增加1.1%,3.1%,4.2%和3.6%。单季晚稻成秧率随着油菜秸秆还田量的增加会小幅下降,而每穗实粒数、千粒重比对照增加,有效穗数也有所下降。免耕直播单季晚稻上适宜的油菜秸秆还田量为5 400 kg/hm2,即3/4的秸秆还田。  相似文献   

8.
[目的]分析不同燕麦品种在辽宁地区机械化种植条件下,不同栽培密度对燕麦产量的影响。[方法]试验选取4个燕麦品种,研究在平肥地块应用免耕播种机的条件下,栽培密度对燕麦产量的影响。[结果]大部分燕麦品种产量随着播种量的增加而增加,但在180kg/hm2和225 kg/hm2的播种密度下,燕麦产量差异不显著。[结论]在该地区适宜的机械化播种量为150~180 kg/hm2。该研究结果为在辽宁地区燕麦机械化生产提供了理论依据。  相似文献   

9.
为探明减量播种对直播稻品质的影响效应,在田间设置5个播种量,分别为142.5、120.0、97.5、75.0、52.5 kg/hm2,研究减量播种对直播稻糙米率、蛋白质含量、直链淀粉含量、食味值及稻米RVA谱(淀粉黏滞性谱)特征参数的影响。结果表明:减量播种对直播稻糙米率、稻米食味值、淀粉RVA谱特征值均产生了影响,播种量为97.5 kg/hm2处理下的糙米率最高(83.65%),稻米的食味得分最高(85分),RVA谱特征值的崩解值最大(141.6 RVU),消减值最低(126.5 RVU)。因此,播种量为97.5 kg/hm2条件下稻米食味品质最佳。  相似文献   

10.
播种量对双季稻套播油菜群体生长的影响   总被引:2,自引:0,他引:2  
为研究稻田三熟制双季稻套播油菜高产栽培技术,筛选适宜的播种量,2016-2017年以丰油730油菜品种为材料,设置3.75kg /hm2、4.50kg /hm2、5.25kg /hm2、6.00kg /hm2和6.75kg/hm2 5个播种量处理,采用大田试验,比较不同播种量对双季稻套播油菜生育进程、密度、成苗率、成株率、个体生长发育、抗病性、产量及产量构成的影响。结果发现:(1)套播油菜密度随着播种量增加而增加,但成苗率和成株率随着播种量的增加而下降。(2)播种量显著影响套播油菜个体生长发育,油菜总叶数、绿叶数、最大叶片叶长和叶宽、根颈粗、单株干重等个体指标随播种量增加而下降,叶面积指数和群体干重等群体指标随着播种量的增加表现先增加后逐渐下降的趋势,以播种量5.25 kg /hm2处理叶面积指数和群体干重最大。(3)菌核病发病率和病情指数均随着播种量的增加而增加。播种量6.75kg/hm2处理比播种量3.75kg/hm2处理发病率和病情指数分别增加了19.83%和9.92%。(4)播种量与分枝高度极显著正相关,与株高、一次分枝数、单株角果数、每角粒数达到极显著负相关水平。(5)产量随着播种量的增加表现出先增加后下降趋势,播种量5.25 kg /hm2处理产量最高,显著高于3.75和4.50kg /hm2的处理,分别增产16.72%和9.36%。可见播种量不足或过大均不利于套播油菜高产群体的构建,本区域内稻田三熟制双季稻套播油菜适宜播种量为5.25~6.00 kg /hm2。  相似文献   

11.
12.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

13.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

14.
Evolutionary aspects of the trade-off between seed size and number in crops   总被引:1,自引:0,他引:1  
Victor O. Sadras   《Field Crops Research》2007,100(2-3):125-138
Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.

The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).

The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors.  相似文献   


15.
Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China.  相似文献   

16.
Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.  相似文献   

17.
Summary

Heterocyclic 1,4-benzoxazin-3-ones and related benzox-azolinones are important natural products of the cereal crops maize, wheat and rye. Much research has focused on the role of these compounds as defensive agents against plant diseases and pests. Studies of a wide variety of biological effects on herbivores and nematodes, plant pathogenic fungi and bacteria are reviewed in this article. Phytotoxic activity of the compounds is also considered with respect to allelopathic interaction with higher plants. Recent investigations of molecular aspects of interactions of cyclic hydroxamic acids and related benzoxazo-linones with acceptor organisms have demonstrated different effective detoxification strategies and tolerance mechanisms. This research has greatly advanced our knowledge about the multiple roles that these allelochemicals play in ecological systems.  相似文献   

18.
Wheat bran is an undervalued by-product of white flour and has great nutritional potential due to its high content in fibres and bioactive compounds. Micronized bran could be used as a food ingredient to improve the nutritional potential of cereal products, or be used as a starting material for other processes (bioactive compound extraction or bran fractionation). The aim of this work was to find a way to efficiently decrease the particle size of bran. The influence of the grinding temperature (ambient or cryogenic grinding) on the granulometric distribution of particles, their composition, and their microstructure was studied, at lab-scale and pilot-scale. It showed that the intrinsic characteristics of bran (glass transition within intermediate layers at −46 °C) had more influence on its grinding behaviour than the type of grinding device used: the particles size distributions obtained after grinding at lab-scale and pilot-scale were very similar. At both scales, the granulometric curves were narrow for cryogenic grinding, while for ambient grinding they were spread over the whole particle size range. Ultrafine particles were obtained in both ambient and cryogenic conditions. Negative temperatures, by increasing the material’s brittleness, favoured a fast fragmentation of bran: one step of cryogenic grinding allowed a median particle size of nearly 50 μm to be reached, whereas three successive steps of ambient grinding were needed for the same result. On the other hand, ambient temperature favoured the dissociation of the different constituent layers of wheat bran, and produced less composite particles than cryogenic grinding.  相似文献   

19.
The technique of spraying plants with inorganic forms of selenium can be employed for phytochemical production of organic selenium compounds. Fractionation of the plant material makes it possible to produce a highly concentrated and well defined selenium supplement with potential use in animal and human nutrition. The fractionation also gives opportunities to combine production of organic selenium compounds with other products, for example plant fibres. Multiple use of plants can contribute to a more efficient utilization of land area (in comparison to monocultures solely adapted to food production). It also gives the opportunity to develop systems suitable for long term fixation of carbon, as long as the plant material is not reoxidised to carbon dioxide. Plant fibres could provide raw material for the production of paper or building materials in combination with the production of organic selenium compounds preferentially accumulated in another fraction of the processed plant.  相似文献   

20.
Summary Macrosiphum euphorbiae, collected in the field from potato plants infected with potato leafroll virus (PLRV), transmitted the virus to fewer potato plants in a field trial than did laboratory-rearedMyzus persicae. In the laboratory,M. persicae was the only efficient vector of PLRV fromPhysalis floridana seedlings, potato sprouts or excised leaves toP. floridana. Two clones ofM. euphorbiae and one clone ofAulacorthum solani transmitted PLRV from infected potato plants toNicotiana clevelandii as effeciently asM. persicae but a clone ofAphis gossypii was an inefficient PLRV vector. An isolate of PLRV, whichM. persicae transmitted inefficiently from potato toN. clevelandii, was also transmitted inefficiently byM. euphorbiae andA. solani.  相似文献   

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