武鸣县木薯间(套)种模式的产量与效益分析

2009年,广西区武鸣县建立6个木薯间(套)种模式示范基地,对验收产量及其效益分析的结果表明：西瓜、南瓜、香瓜或毛节瓜套种木薯、以及木薯间作花生或大豆的鲜薯单产比对照(纯种木薯)提高6.1%～25.2%,总收入是对照的1.6～4.2倍,净收入是对照的1.7～4.9倍,其中,瓜类套种的效益优于花生和大豆间作。2009年,以上木薯间(套)种模式的种植总面积达到13 800 hm2,占全县的49.3%。     

麦套花生套期与密度优化配置研究

采用二次饱和D-最优设计建立了小麦行距为30cm的麦套花生套期和密度与产量的数学模型.进一步分析表明,花生套期和密度对花生产量作用显著,且密度效应大于套期.套种花生最适播期为麦收前22d,与其相配套的最适密度为15.55×104穴/hm2,最高产量可达到4 679.4kg/hm2.适期过后,套期每推迟5d,花生平均减产187.2kg/hm2.花生产量在3 500kg/hm2以上的优化措施组合为:5月10日～5月29日套种,密度14.66×104～20.72×104穴/hm2.     

甘蔗宽窄行间套种植效益分析

为提高土地的利用率和实现农业机械化操作,提高蔗农综合经济效益,进行宽窄行间套种玉米、大豆和花生试验,探索出甘蔗宽窄行种植对甘蔗农艺性状、产量和甘蔗糖分的影响。试验结果表明,宽窄行种植的甘蔗比普通种植的产量高1.9t/hm2,增1.8%。同时玉米收入达6.15t/hm2,产值达到12915元/hm2,两样产值比普通甘蔗种植的产值高13713元/hm2,增幅达30.35%。同时投入产出最高的是间套种花生为3.5∶1。通过探索宽窄行间套种提高植蔗的综合效益,达到农民增收、企业增效、农业增产的目的。     

宽幅麦套种花生套期与密度研究

麦油两熟制一体化高产栽培大田试验结果表明 ,宽幅麦套种花生套期和密度对麦套花生产量作用显著 ,套期效应大于密度穴数 ,高产麦套花生必须适期套种。麦套花生最适套期为麦收前 5 3天 ( 2 8/ 4) ,适期过后 ,套期每推迟 1天 ,花生约减产 14.6kg/hm2 ;适期套种时 ,麦套花生适宜的公顷穴数为 7995 0 ,夏直播花生适宜的公顷穴数为 8715 0。     

施钾量对花生养分吸收及产量品质的影响

田间试验研究钾肥用量对花生生长、养分吸收、产量和品质的影响.结果表明,0～60kg/hm2范围内,随施钾量增加,花生荚果数增加,产量提高,60kg/hm2用量下,花生产量最高3640kg/hm2,比不施钾肥增产18.17％.0～90kg/hm2范围内,高施钾量可促进氮磷钾吸收,90kg/hm2用量下,花生粗脂肪含量最高为51.56％,比不施钾肥提高5.48％.超过90kg/hm2,增加施钾量导致花生养分吸收减少,荚果数下降,蛋白质、粗脂肪含量和产量随之下降.本试验条件下达到最佳经济效益的花生施钾量为63.3kg/hm2,产量可达到3611kg/hm2.     

精播麦套花生套期、肥料与密度优化配置

大田条件下采用二次饱和D—最优设计建立了精播麦套花生套期、密度和N肥与产量的数学模型。分析表明: (1)套期与密度、密度与肥料间呈负向交互效应。套期晚,花生适宜密度应相应增加;密度增加,N肥用量可适当减少。套期与肥料呈正向交互效应,套期早, N 肥用量也应适当增加。( 2) 麦套花生最高产量可达到5 795. 4kg/hm2 ,相应的措施组合为:麦收前22d套种,每公顷播20. 7万株,施N 89. 3kg。产量在4 500～5 250kg/hm2 范围内的措施组合为:麦收前18～29d套种,每公顷播18. 8～22. 2万株,施N 49. 4～90. 7kg;产量在5 250～5 795kg/hm2范围内的措施组合为:麦收前17～22d套种,每公顷播18. 9～22. 7万株,施N 72. 7～108. 9kg。(3)夏直播花生最高产量可达到4 873. 0kg/hm2 ,相应的措施组合为:每公顷播20. 8万株,施N 85. 4 kg/hm2。     

山东省不同生态区域花生种植方式综合评价研究

大田试验表明,在小麦花生两熟制栽培中,不同种植方式的小麦产量基本随小麦行距的增加而降低,无论鲁东、鲁西,小麦产量均以畦田麦最高,大垄宽幅麦最低。除春花生外,花生产量大垄宽幅麦套种最高,一般等行麦套种(鲁东)和畦田麦夏直播(鲁西)最低;不同种植方式小麦、花生单作经济效益高低与各自的产量表现一致。在鲁东,全年效益大垄宽幅麦套种最高,达到15921.0元/hm2,一般等行麦套种最低,在12000元/hm2以下。在鲁西,小垄宽幅麦套种和一般等行麦套种效益较高,在16000元/hm2以上,春花生最低;不同种植方式前茬小麦单季光能利用率高低与产量水平一致,畦田麦达到了1.6%以上。花生单作光能利用率明显高于小麦,且并不与产量表现完全一致。鲁东春播最高,达到了2.23%,大垄宽幅麦和夏直播次之,达到了2%左右。鲁西夏直播最高,达到了2.28%,春花生次之,达到了2.22%。全年光能利用率,鲁东畦田麦夏直播最高,鲁西小垄宽幅麦套种最高,此两种方式光能利用率均在1.8%以上。春花生全年光能利用率最低,约为1%。综合本研究结果,大垄宽幅麦套种、畦田麦夏直播和春花生为鲁东较为适宜的种植方式;小垄宽幅麦套种、畦田麦夏直播为鲁西较为适宜的种植方式,除非旱薄地鲁西一般不宜采用春播方式。     

不同木薯/花生模式下的产量表现及其经济产出研究

研究了4种木薯株行距配置0.8 m×0.8 m(M_1)、0.6 m×1.0 m(M_2)、0.8 m×(1.0 m+0.6 m)(M_3)、0.6 m×(1.0 m+0.8 m)(M4),木薯单作与相应木薯/花生体系的产量表现和经济产出的影响。结果表明:4种间作处理的土地当量比(LER)和产值当量(VOE)均大于1,木薯实际产量亏损(AYLc)均大于0,木薯偏土地当量比(PLER-C)均高于木薯在间作和单作中所占的土地面积之比,即4种间作模式均能提高土地利用率,且对木薯来说均具有间作优势;M3间作处理中花生相对于木薯的竞争力(Apc)和花生实际产量亏损(AYLp)大于0,而经济产出则比M3单作木薯高出了237元/667 m2,总的实际产量亏损(AYL)为1.07,在4种间作处理中数值最大。故木薯/花生间作体系中M3木薯株行距配置的间作产量优势和经济效益优势最佳。     

宿根甘蔗套种马铃薯宽窄行栽培技术研究

为提高宿根甘蔗套种马铃薯经济效益,通过采用宽窄行种植、多种密度处理的方法,研究宿根甘蔗套种马铃薯中马铃薯密度与甘蔗产量和品质、马铃薯产量和商品率、土地复合产值和新增纯收入之间的关系。结果表明：在播幅为2.0 m的宿根甘蔗套种马铃薯宽窄行栽培中,当马铃薯密度达3.0万粒/hm2时,土地复合产值最高、经济效益最好,其中,马铃薯产量达28 600 kg/hm2,商品率达72.3％;甘蔗产量达168 000 kg/hm2,比纯种增16.2％;甘蔗糖锤度达19.9％,比纯种提高0.3个百分点;复合产值达135 985元/hm2,比甘蔗纯种增119.7％;新增纯收入122 905 元/hm2,比甘蔗纯种增151.8％。     

平衡施肥对木薯产量及品质的影响初报

采用"3414"完全随机区组设计,开展木薯平衡施肥田间试验,研究施肥对木薯产量及品质的影响.其结果表明:(1)施肥对木薯产量有极显著的增产效应,氮、磷、钾肥增产的主次顺序为K>N>P.(2)木薯最高产量的氮、礴、钾优化施肥组合为N:150.00 kg/hm2,P2O5:36.75 kg/hm2,K2O:150.00 kg/hm2,此时最高产量为36.04t/hm2,其最佳施肥配比为N:P2O5:K2O=4:1:4;木薯最佳施肥利润的氮、磷、钾优化施肥组合为N:150 kg/hm2、P2O5:29.50 kg/hm2、K2O:150 kg/hm2,其最佳施肥利润达10 780.11元/hm2,此时产量为36.00 t/hm2,其最佳施肥利润配比为N:P2O5:K20=5:1:5.(3)施肥对木薯淀粉含量有极显著的影响,氮、磷、钾肥对木薯淀粉含量影响的主次顺序为:N>K>P.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

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.     

Novel food and non-food uses for sorghum and millets

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.     

Evolutionary aspects of the trade-off between seed size and number in crops

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.     

Citrus Flavonoids in Fruit and Traditional Chinese Medicinal Food Ingredients in China

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.     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

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.     

Role of Benzoxazinones in Cereals

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.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part I: Influence of ultra-fine grinding

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.     

Multiple use of plants: Studies on selenium incorporation in some agricultural species for the production of organic selenium compounds

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.     

Biological factors influencing the transmission of potato leafroll virus by different aphid species

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.