The effect of flat plastic film covering on the development of lettuce in two places with different ecological conditions

Thanks to the joint trials and observation programmes carried out simultaneously at the Experimental Station for Vegetable Crops of St. Katelijne-Waver (Belgium) and at the Institute for Vegetables Crops at Geisenheim (German Federal Republic). It has been possible to determine the relationship between the meteorological or microclimatic condition and the behaviour of lettuce in two ecologically different places.The trials concerned lettuce which, after having been planted out, was given a flat cover of polythene film during 8, 15, 21 or 23 days. In the more continental climate of Geisenheim there was more sunshine and the weather was drier than in the more maritime climate of St. Katelijne-Waver. These different climatic conditions account for the fact that the average weight of both fresh and dry heads was lower at Geisenheim than at St. Katelijne-Waver. The size of leaves was also smaller at Geisenheim. The number of leaves, however, was larger there than at St. Katelijne-Waver.     

早蟠桃设施栽培试验

１９９８～１９９９年用６年生肥城桃改接的早蟠桃做试材,进行了塑料薄膜昆温室栽培试验。通过加强土肥水管理,树木讷人,花果管理及合理控制温湿度,取得了成功。成熟期４月中旬,平均单果重５３ｇ,可溶性固形物含量１５％,析合６６６．７ｍ＾２,产量达１１９４．６ｋｇ,经济效益显著。     

树冠直接覆膜对清见橘橙树冠内环境因子的影响

以清见橘橙(Citrus sinensis*Citrus unshiu Marc)为材料,研究了果实越冬期间直接覆盖薄膜的树冠内环境因子的变化.结果表明,覆膜可显著提高树冠内温度,2007-2008年试验期间的日平均温度在覆膜树冠上部为11.5℃,中部为10,5℃,下部为9.0℃,对照为8.3℃;2008-2009年试...     

Effects of soil temperature on head development of Cos lettuce

Cos lettuce plants (Lactuca sativa L. cultivar ‘Romana’) of 2 ages were grown for 30 days with soil temperatures of 12°, 20°, 28° or 36°C. The highest temperature caused poor growth and heading and quick head disintegration. Best heading occurred mainly at lower temperature, although the lowest one sometimes delayed growth. Higher temperatures did not enhance real bolting, as growth of the inner stem was accelerated.     

宁夏地区小拱棚不同覆盖类型对西瓜生长发育的影响及效益比较

在两膜覆盖基础上增加草苫覆盖和一层膜覆盖2种类型,对3种小拱棚覆盖类型进行比较试验。结果表明,3种覆盖类型均有利于西瓜的生长发育;根据成熟期提前、产量和经济效益综合评价,两膜一苫类型最好,其次为三膜覆盖,最后是两膜覆盖。以育苗方式比较,两膜一苫每667m2的经济效益比三膜覆盖高654元,比两膜覆盖高1100元。两膜一苫类型是值得在宁夏大力推广的小拱棚栽培模式。     

树盘覆草对石榴生长发育的影响

石榴树大都生长在土层瘠薄、砾石多、有机质含量少、保水保肥性能差、冲刷严重、无浇水条件的山坡上，产量的提高难度很大。针对此问题枣庄市农科院从1992年起开展了石榴树盘覆草研究。3年的试验研究证明，树盘覆草简便易行，投资少，见效快，收益大。     

重庆开县柑橘冬季树冠覆膜对落果及果实品质的影响研究

通过对开县长沙锦橙柑橘果园实施35．55 hm2柑橘冬季树冠覆膜防冻试验,并对该果园防冻后柑橘果实进行落果数、果实可食率、果汁率、枯水个数、可溶性固形物（TSS）含量、维生素c（vc）含量、总酸（TA）含量的测定,发现采取树冠覆膜的柑橘落果数、果实果汁率、可溶性固形物（TSS）含量、维生素c（vc）含量、总酸（TA）含量均显著减少,而果实可食率、枯水个数均没有显著的变化。     

遮阴及地膜覆盖对黄皮果实表面温湿度变化及果实品质的影响

以金鸡心黄皮为试材,研究了遮阴及地膜覆盖处理对黄皮果实品质与果实表面温湿度变化的影响。结果表明：阴雨天气下,遮阴及遮阴＋地膜覆盖处理的果实表面日平均湿度低;晴天天气下,地膜覆盖处理及对照果实表面的日平均温度高,昼夜温差大,阴雨及晴天天气下温度变化、湿度变化趋势基本一致;地膜覆盖提高了果实品质,遮阴及遮阴＋地膜覆盖降低了果实好果率。     

覆膜与施肥对花籽山药产量的影响研究

通过对山药进行覆膜和不同配方施肥处理研究,发现单一肥料效果不如多种肥料搭配施用,覆膜和混施复合肥与有机肥对山药增产效果显著。     

地膜反光膜在特早熟蜜柑(稻叶)上的应用初报

龙岩特早熟蜜柑(稻叶)是龙岩市特色优势水果,深受人们的喜爱,在国内外享有一定的知名度.为进一步提高龙岩特早熟蜜柑(稻叶)的品质,提早成熟,2004年我们开展了地膜、反光膜在龙岩特早熟蜜柑(稻叶)上的应用试验,现将结果报道如下:     

Weed control and yield response of soil solarization with different plastic films in lettuce

Phase out of most chemicals available for weed management renewed the interest in soil solarization as a technically effective and environmentally safe practice for lettuce weed control in hot summer areas. Properties of solarizing films and lettuce crop system may considerably affect weed control and yield response of soil solarization. Different solarizing films, including low-density polyethylene, ethylene-vinyl acetate copolymer, low-density polyethylene–ethylene-vinyl acetate coextruded and a biodegradable corn starch-based film, were evaluated in 2003 and 2004 for weed control and lettuce yield response under field and greenhouse conditions in Southern Italy. Soil solarization strongly reduced weed density and biomass in both greenhouse and in the field, with no significant differences among the tested plastic films. Most annual weeds were completely controlled by soil solarization, except amaranth, Amaranthus spp., in soil solarized with biodegradable film in the field. Emergence of mediterranean sweetclover, Melilotus sulcatus, was stimulated by soil solarization in greenhouse. In the field, Cyprus vetch, Lathyrus ochrus, was found in solarized plots though absent in untreated soil. Perennial weeds were not affected by soil solarization, except a strong control of canadian thistle, Cirsium arvense, in the field. Lettuce yield resulted significantly higher in solarized soil than in control plots, with no significant differences among the solarizing materials. All tested materials proved to be technically effective for soil solarization in lettuce, though low resistance and short durability of biodegradable film may suggest its application mainly to soil solarization in greenhouse or in organic systems.     

平菇大豆酸奶的研制

平菇肉质细嫩,味道鲜美,富含多种氨基酸和磷、钾、铁、锌、铜等微量元素,有较高的营养价值。平菇中的平菇多糖具有抗肿瘤,提高人体免疫力的功效,经常食用平菇对减少体内胆固醇,降低血压和增进健康有明显效果。且平菇容易栽培,产量高,是一种深受消费者喜爱具有开发价值的食用真菌。大豆含有大量植物蛋白质,质量最好,它的氨基酸模式接近人体的需要,且富含粮谷类缺乏的赖氨酸,还含有VB、VE、多种矿物质元素,并可除去人体内过剩的胆固醇,大豆中还含有人体所必需的亚油酸,亚麻酸等必需脂肪酸及其他生理活性物质,是目前国家重点开肪酸及其他生理…     

Effects of nitrogen availability and supplementary light on the nitrate content of soil-grown lettuce

Summary

The effect of nitrogen availability and low level supplementary light on the growth and nitrate content of butterhead lettuce (Lactuca sativa var. capitata L.) grown in soil under greenhouse conditions in winter was studied. No significant interactions between nitrogen availability and supplementary light on yield, nitrate content, osmotic potential of expressed leaf sap and component osmotica were found. Supplementary light greatly increased plant growth and resulted in earlier harvest. When harvested with similar fresh weights, plant nitrate content was significantly reduced by supplementary light although the effect was slight. The reduced contribution of nitrate to sap osmotic potential at the higher light level was accompanied by a significant increase in the contribution of sucrose. While plant fresh weight was unaffected by the rate of nitrogen application, a positive correlation between nitrate content and nitrogen application rate was found. Reduced nitrate content at low nitrogen application rates was accompanied by increased contributions of chloride, glucose and sucrose to sap osmotic potential.     

双膜覆盖对文玩核桃成熟度的影响

在发展文玩核桃过程中,有的核桃坚果不成熟,有白边、花边现象,严重影响经济收入,采用双膜覆盖技术,提高了果实成熟度可有效解决这一问题。     

透湿性反光膜覆盖对柑橘树体微环境、新梢生长及果实发育的影响

【目的】探索透湿性反光膜覆盖对柑橘冠层微域环境、新梢生长及果实品质的影响,为柑橘提质增效提供新的参考模式。【方法】以3 300 m~2、32 a生‘宫川’温州蜜柑为试材,树冠下地面全面覆盖白色透湿性反光膜后,选取树势一致的植株,测定冠层光辐射特征、土壤理化性质、树体生长及果实品质等。【结果】覆盖透湿性反光膜没有显著影响果实发育过程中的树体生长。柑橘冠层反射光强度、可见光光质及叶片的净光合速率均得到了显著提升。覆膜不同深度的土壤含水量均有变化,10 cm处降低了7.55%,20 cm差异不大,30 cm降低了2%,40 cm降低了6%。覆膜过程中柑橘叶片中多种元素含量及采收期根际土壤的细菌、真菌数量均有明显变化。采收时,果实纵横径大幅下降;果实亮度提高,着色加强;果皮叶绿素a含量下降17%,类胡萝卜素总量提升了36%;可溶性固形物含量显著提升,可滴定酸含量显著降低;葡萄糖、果糖、蔗糖及总糖含量均有明显提升;维生素C含量提升了22%。【结论】透湿性反光膜可改善光照条件,调节土壤微环境,影响树体生长及光合作用,最终提升温州蜜柑的果实内外在品质。     

紫光膜在保护地果树生产上应用效果的研究

在保护地果树生产上选用透光率高、保温性能好、耐用、防尘、防雾效果好的透明覆盖物，是实现节能、高效生产的重要途径。作者于1998－2000年在辽宁农业职业技术学院试验地，利用对比法对紫光膜的透光性、保温性以及对果树的生长发育的影响等进行研究。结果表明，紫光膜透光率高，保温性能好，耐用，防尘、防雾效果好，能促进果树生长发育，提早开华结实，提高产量、产值、提高果品质量。     

腐殖酸水溶性肥料对莴苣产量和效益的影响

为了解施用腐殖酸水溶性肥料对莴苣产量和效益的影响,以便在生产上推广应用,笔者在莴苣生长期进行了施用试验。结果表明,在莴苣旺盛生长期和茎部肥大期,每667m2用腐殖酸水溶性肥料100mL加水50kg进行叶面喷施,能够使莴苣产量提高170kg以上,增产率在7%以上,667m2可增加收入200元,投入产出比达到1∶10。莴苣喷施该肥料,技术简单实用,增产增效明显,建议在生产上推广应用。     

Effects of nitrate,ammonium and chloride application on the yield and nitrate content of soil-grown lettuce

Summary

The effect of nitrogen availability and nitrogen form on the yield and nitrate content of butterhead lettuce (Lactuca sativa var. capitata L.) grown in soil under greenhouse conditions was studied. The extent to which chloride application can reduce nitrate content by supplying the plant with an alternative osmotically active anion, and whether the presence of ammonium in the soil is a necessary prerequisite for an effect of chloride, was also examined. Reducing NO₃-N availability from 260 to 200 kg N ha^–1 significantly reduced nitrate content while head fresh weight was unaffected. Further reducing NO₃-N availability to 120 kg N ha^–1 significantly reduced both nitrate content and fresh weight. Substituting 40% of the available NO₃-N with NH₄-N significantly reduced nitrate content while fresh weight was unaffected. The effect of NH₄-N application on plant nitrate content was enhanced by the application of the nitrification inhibitor dicyandiamide (DCD). Despite increasing chloride uptake, the application of chloride had no significant effect on head fresh weight or nitrate content when available nitrogen was in the nitrate form irrespective of the level of nitrogen application. Chloride application similarly had no effect on head fresh weight or nitrate content when applied together with ammonium without the nitrification inhibitor DCD, despite a greater uptake of chloride. Where both ammonium and DCD were applied, however, chloride application significantly reduced head nitrate content.     

间作白三叶草和覆膜对甜樱桃园土壤温度变化的影响

于甜樱桃园进行垄上覆膜和行间种白三叶草试验,观察其对土壤温度和新梢生长的影响.结果表明,垄上覆草和行间种白三叶草后,不同深度和不同时刻的土壤温度与清耕区有明显差别.两项措施均能降低各土层温度日较差,增加同土层温度稳定性.早春覆膜有利于提高地温;行间种白三叶草有利于降低地表温度,降温效果明显.覆膜和行间种白三叶草对2年生樱桃的新梢生长具良好的促进作用.     

植后苗干包膜对柿栽植成活率和生长的影响

3月22日至4月22日栽植柿苗,栽后用塑膜包严苗干,成活率高达9．7．9％,3月22日栽植者100％成活,当年平均单株抽生新梢4．6条,至7月20日调查,新梢平均长58cm。