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1.
水分对旱稻土壤及植株中主要营养元素含量的影响   总被引:4,自引:0,他引:4  
在防雨棚池栽条件下研究了不同水分处理下土壤矿质元素的释放及旱稻植株对矿质元素的吸收利用特点。结果表明:土壤水分对土壤N、P、K含量及植株养分吸收存在明显影响。随着土壤水分含量的提高,土壤硝态氪含量显著下降,氨态氪含量显著上升;磷素在低水分处理下先升高后基本保持较高水平,而在高水分处理下有一个升降升的变化过程;钾素在65%、100%水分处理下在分蘖中后期显著大于其它水分处理,而在分蘖前期各水分处理都有一个先降后升的变化趋势。在植株对矿质元素的吸收上,100%水分处理下植株体内的全氮含量一直呈下降趋势,65%、75%处理下磷素变化呈“U”型,其余各处理下植株体内的N、P、K含量都呈W型变化。随土壤含水量的增加,旱稻植株对N、P、K的吸收总量均增加。  相似文献   

2.
不同生物有机肥施肥方法对压砂西瓜生长及产量的影响   总被引:4,自引:0,他引:4  
2009年在宁夏中卫香山乡采用田间试验的方法,比较了穴施和条施生物有机肥对压砂西瓜生长及产量的影响.结果表明:与条施生物有机肥相比,穴施条件下,西瓜生育前期叶面积指数增加了80% ~ 119%;生育中后期主蔓长20.6 cm,增加25.4%;叶片数也较多;单瓜重增加了43%,中心糖含量和边糖含量分别提高了9%和8%;同...  相似文献   

3.
Abstract

An established banana field was treated by applying three compounds, fenamiphos, isazofos and carbofuran, to the soil around each mat. The tested compounds were found to reduce significantly soil and root nematode populations. The production cycle of the nematocide treatments was 24 days faster than that of the untreated control. Application of the above chemicals enhanced to the total production of banana. Carbofuran may be ranked top of these nematocides, followed by isazofos. Application of 2 g a.i. of carbofuran three times at intervals of 4 months, yielded 2.66 tonnes per acre more than that of the control.  相似文献   

4.
采用二因素裂区设计,以保水剂和活性炭、硅藻土、凹凸棒为填充剂的包衣材料制作丸粒化胡麻种子,研究了丸粒化处理对胡麻种子萌发和幼苗生长的影响。结果表明:与不加保水剂相比,保水剂质量与种子质量为1∶1时,丸粒种子的活力指数和出苗率显著提高20.11%、18.62%;随着保水剂含量的增加,幼苗的根冠比显著减小3.25%。包衣剂中以活性炭:凹凸棒=1∶1为填充剂的发芽率和出苗率比不加填充剂的明显提高6.79%、22.41%,幼苗生长最健壮。与未丸粒化的种子相比,当保水剂质量与种子质量为1∶1时,以活性炭:凹凸棒=1∶1为填充剂的丸粒种子发芽指数、活力指数和出苗率显著提高,而且幼苗的茎粗、叶面积和根冠比分别显著增加11.02%、27.35%、28.07%。可见,适量的保水剂(保水剂质量与种子质量为1∶1)和以活性炭、凹凸棒为填充剂的包衣剂能提高胡麻种子活力,增加出苗率,使幼苗的干物质重增大,根系发达,根冠比提高,为胡麻高产奠定了良好的基础。  相似文献   

5.
Abstract

Two field experiments on chemical weed control in Faro 41 upland rice (Oryza sativa L.) variety were conducted at a rainforest site near the National Cereals Research Institute, Amakama Substation in 1989 and 1990. The herbicides tested were a coformulated mixture of pretilachlor and dimethametryne at 1.5, 2.0 and 2.5 kg a.i./ha, a co‐formulated mixture of piperophos and propanil applied at 3.16 and 3.95 kg a.i./ha, and Oxadiazon at 1.0 kg a.i./ha. Two hand weedings and a ‘no weeding’ treatment were included. The herbicides were applied 5 days after planting. All were safely selective to the crop. Most provided adequate weed control through 8–12 weeks after planting. Weeds controlled included Cynodon dactylon, Commelina benghalensis, Dlgitaria horizontalis, Eleusine indica, Panicum maximum and Pennisetum purpureum as grass weeds. The broadleaf weeds were Emilia sonchifolia, Ageratum conyzoides, Portulaca oleraceae, Richardia brasiliensis and Ipomoea Involuncrata. The sedges Mariscus alternifolius and Cyperus esculentus were encountered in the plots. Pretilachlordimethametryne at 2.5 kg a.i./ha had the best weeding score. Twoyear average grain yields of 1.7–2.6 t/ha were obtained from the herbicide treatments. With only 0.4 t/ha from the unweeded treatment, yield losses of more than 80% were recorded.  相似文献   

6.
7.
河南黄淮麦茬稻区适宜旱稻品种 及鉴定指标的筛选   总被引:1,自引:0,他引:1  
为筛选适合河南黄淮麦茬稻区种植的优良旱稻品种,建立适宜的旱稻鉴定评价体系,利用河南地区主要推广的23个水、旱稻为材料,于旱棚内旱直播种植,在孕穗期和成熟期对植株形态、生理生化性状和单株产量进行测定和分析。结果表明,水分胁迫条件下,高产品种的平均单株产量、分蘖数、株高、地上部鲜重和根基粗分别是低产品种的2.46、1.78、1.17、1.57和1.18倍,分蘖数、株高、地上部鲜重和根基粗与旱田单株产量呈显著正相关。旱田产量和分蘖数可以作为河南黄淮麦茬旱稻的评价指标,株高、地上部鲜重和根基粗可以作为辅助指标。初步筛选洛稻998、徐旱702、原旱稻3号和郑旱2号为适宜推广的高产抗旱品种。  相似文献   

8.
Research in the various crop protection disciplines is carried out at the Central Norwegian Plant Protection Institute near Oslo: it includes studies on pesticide efficacy, problems of uptake, breakdown and residues. This agency is further in charge of the extension of practical knowledge and has a supervising capacity for the Plant Inspection Service. Some of the various problems which are of major concern for Norway are reviewed and ways for a proper integration of chemical and alternative methods studied.  相似文献   

9.
THEORY AND PRACTICE OF WEED CONTROL. R. J. Stephens. Science in Horticulture Series. Macmillan, London, 1982. ISBN 0 333 21294 0. Pp.215. Price (paperback) £8.95.

OIL PALM DISEASES AND DISORDERS. P. D. Turner. Oxford University Press, Selangor, Malaysia, 1981. ISBN 0 19 580468 6. Pp. 280.

MAJOR WEEDS OF RICE IN SOUTH AND SOUTHEAST ASIA. K. Moody. International Rice Research Institute, Los Baños, Laguna, Philippines, 1981. Pp. 79.

BIOLOGICAL CONTROL OF WEEDS ‐ A WORLD CATALOGUE OF AGENTS AND THEIR TARGET WEEDS. Edited by M. H. Julien. Commonwealth Agricultural Bureaux, Farnham Royal, UK, 1982. ISBN 0 85198 494 0. Pp 108. Price £8.

COMPENDIUM OF SOYBEAN DISEASES. Second Edition. Edited by J. B. Sinclair. Amercian Phytopathological Society, St. Paul, Minnesota, 1982. Pp. 104. Price US $12.00.

FIELD WORKER EXPOSURE DURING PESTICIDE APPLICATION. Edited by W. F. Tordoir and E. A. H. van Heemstra. Elsevier, Amsterdam, 1980. ISBN 0 444 41879 2. Pp. 208. Price US $45.00.

EDUCATION AND SAFE HANDLING IN PESTICIDE APPLICATION. Edited by E. A. H. van Heemstra and W. F. Tordoir. Elsevier, Amsterdam, 1982. ISBN 0 444 42041 X. Pp. 302. Price US $69.75.

LES PRINCIPAUX ENNEMIS DES CULTURES MARAICHERES AU SENEGAL E. F. Collingwood, L. Bourdouxhe and M. Defrancq. Centre pour le Developpement de ('Horticulture, Dakar, 1982.  相似文献   

10.
不同旱稻品种灌浆期抗旱生理适应性的研究   总被引:3,自引:0,他引:3  
选择抗旱性不同的4个旱稻品种,对其灌浆期旗叶抗旱性生理指标进行测定。结果表明:超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性及游离脯氨酸含量均为抗旱性较强品种(旱稻15号,旱稻2号)极显著地高于抗旱性较弱品种(旱稻1号,旱稻3号);丙二醛(MDA)含量和细胞膜相对透性大小表现为抗旱性较强品种(旱稻15号,旱稻2号)极显著地低于抗旱性较弱品种(旱稻1号,旱稻3号)。SOD、POD、CAT活性和丙二醛含量、游离脯氨酸含量、细胞膜相对透性可用来说明旱稻品种之间的抗旱生理适应性的差异。  相似文献   

11.
利用植物生长调节剂Z-S对高产旱稻北农大65在三叶一心、拔节期和孕穗期进行叶面喷施,研究其对高产旱稻花后衰老的影响.结果表明:浓度为100 mg/kg Z-S叶面喷施后根系活力、根系SOD、CAT活性及可溶性蛋白质含量均明显高于其它处理;100 mg/kg Z-S喷施后旗叶可溶性蛋白质含量明显增加,而旗叶SOD、CAT活性较其它处理没有明显上升,高浓度处理(≥300 mg/kg)促进植株体内MDA累积,造成早衰.从产量方面看,100 mg/kg的Z-S喷施能有效提高旱稻的产量和经济系数.  相似文献   

12.
Abstract

The properties of banana spray oils have been investigated by a number of researchers. The results of these investigations are reviewed in this paper, and include information on volatility (distillation range, flash point); flow characteristics (viscosity, pour point); other physical properties (specific gravity, colour, aniline point); and chemical properties (unsulphonated mineral residues, aromatics, paraffins and naphthenes).

A comparison of distillation curves is of greater significance than comparison of individual boiling points. Such a comparison will show whether any one oil product is a homogeneous oil or a mixture of heavy and light oils. Disease control is closely related to volatility of the spray oil; the lower the volatility of the oil the better the disease control. Phytotoxicity (leaf-flecking) increases as the percentage volatility of the spray oil decreases. Oil volatility governs the amount of oil remaining on the leaf after application. The initial amount of oil applied to the leaf is of less significance in the fungistatic effect than is the amount of oil remaining on or in the leaf. From a viewpoint of Sigatoka disease control, flash points are of little significance, but must be considered from the viewpoint of safety in storage, transportation and use.

As the viscosity of spray oils increases [in the range 35-100 Saybolt Universal Seconds (SUS) at 100[ddot]F] disease incidence decreases and phytotoxicity increases on sprayed banana leaves. The naphthenic oils are superior to the paraffinic oils, particularly in the viscosity range of 75-85 SUS at 100[ddot]F, for spraying bananas.

The performance of banana spray oils is related to the proportions of the major hydrocarbon groups (aromatics, naphthenes and paraffins) present in the oil. Properties such as specific gravity and aniline point are indicative of the proportions of the major hydrocarbon groups in a spray oil.

Colour of mineral oils is of no significance in the control of Sigatoka disease. Light mineral oils with unsulphonated mineral residue (U.M.R.) in the range of 70-99.9 are equally effective in Sigatoka disease control regardless of U.M.R. However, the degree of leaf damage (phytotoxicity) is directly related to U.M.R. value. The oils of high U.M.R. cause the least damage. The aromatic fraction of four spray oils tested (heavy paraffinic, light paraffinic, heavy naphthenic and light naphthenic) caused abundant phytotoxicity at a deposit level of 3 US gal/ac. There was little or no phytotoxicity and no appreciable disease control at a deposit level of 1.5 US gal/ac. Paraffinic and naphthenic oils of comparable U.M.R. value (94-95%) and viscosity (74-75 SUS at 100[ddot]F) provide good disease control within the deposit range 1.4-2.1 US gal/ac. At these deposit levels the naphthenic oil causes only 20 and 50% respectively as much phytotoxic flecking as the paraffinic oil. Photosynthesis is inhibited by the application of petroleum oil to banana leaves.

It is the opinion of the writer that a long-term trial (a minimum of two years) should be conducted to evaluate the effect of a comparable naphthenic and paraffinic oil on Sigatoka disease control and banana yield.  相似文献   

13.
采用营养液培养法和石蜡切片技术,研究了紫茎泽兰淋溶主效化感物质(泽兰二酮和羟基泽兰酮)对旱稻幼苗根尖解剖结构的影响。结果表明:两个化感物质分别处理后,旱稻幼苗的根呈现短小肿胀、侧根缺乏、且对营养液的吸收明显减少,这些症状随着化感物质浓度的增加而加剧。石蜡切片的结果表明,和对照相比,化感物质处理后的旱稻幼苗根尖的解剖结构发生了明显的变化,主要表现在顶端分生组织、静止中心和根冠的细胞排列混乱,细胞间隙加大,皮层薄壁组织细胞变得短而粗,以及表皮层细胞大量脱落等。讨论认为,旱稻幼苗根的形态结构变化,主要与紫茎泽兰化感物质对受体植物吲哚乙酸的干扰相关。  相似文献   

14.
Two sesquiterpene‐derivative compounds, 4,7‐dimethyl‐1‐(propan?2‐ylidene)–1,4,4a,8a‐tetrahydronaphthalene‐2,6(1H, 7H)‐dione (DTD) and 6‐hydroxy‐5‐isopropyl‐3,8‐dimethyl?4a,5,6,7,8,8a‐hexahydronaphthalen‐2(1H)–one (HHO), are the major putative allelochemicals of the aqueous leachates of Ageratina adenophora. A laboratory experiment was conducted, using the hydroponic method, to evaluate the cellular and ultrastructural changes in the seedling roots of upland rice under the stress of DTD and HHO. The subsequent changes were observed in the treated upland rice roots in comparison with their controls. The scanning electron microscopy results showed that the DTD‐treated root tip cells turned into an irregular arrangement and shape and that most of them were wizened, with a poor cytoplasm. In the HHO treatment, the root tips had many irregularly shaped cells, with a greater number of sloughing cells, as well as short, wide cells that resulted in spherical and wider, but shorter, roots. At the ultrastructural level, DTD and HHO induced irregularly shaped and lobed nuclei, increased cytoplasmic vacuolation, reduced ribosome density and dictyosomes, and a reduced number of mitochondria in the cells, which indicated limited protein transportation and a reduced capability to export substances for cell development and growth in the upland rice seedling roots. The overall effect of HHO on the upland rice seedlings was more pronounced than that of DTD.  相似文献   

15.
为了探明旱作对水稻氮、磷利用效率的影响以及产量与氮磷营养的关系,通过温室微区试验研究了传统水作(CT)、覆膜旱作(FM)和裸地旱作(LD)下水稻产量、产量构成因子、氮磷累积、氮磷收获指数、氮磷生理利用效率等的差异。结果表明:旱作在一定程度上阻碍了水稻生长,降低了稻谷产量,产量构成因子中的千粒重受旱作影响较小;FM处理的稻谷产量比CT处理下降6.47%,但未达显著差异,另外,氮、磷累积量均没有受到明显影响;然而LD处理产量的下降幅度则达14.9%,且氮磷累积量均明显下降;与氮磷生理利用效率相比,水稻氮磷收获指数对旱作敏感程度更高,FM和LD处理均显著低于CT处理,其中,LD处理下降程度更大。相关性分析表明,水稻产量与氮素营养的相关性要高于与磷素营养的相关性。总之,FM处理能有效降低旱作对水稻生长及养分利用效率的影响,调控好氮、磷营养,特别是氮素营养有利于旱作条件下水稻生长及产量形成。  相似文献   

16.
病虫害严重影响我国农业生产,每年造成巨额经济损失,传统化学农药虽然在一定程度上能够减轻这些危害,但其不合理的使用也造成严重的负面影响,亟需开发新型生物农药。海洋真菌生存于独特的海洋环境中,形成了有别于陆生真菌的生存繁殖方式和遗传代谢机制,能够产生许多结构新颖、生物活性显著的次级代谢产物,其中许多化合物具有抗植物病原菌、杀虫和抗病毒等农用生物活性,具有开发成为新型生物农药的巨大潜力。本文综述了2010年以来前人在海洋真菌次级代谢产物农用生物活性方面的研究成果,涵盖了90个化合物,结构类型主要包括聚酮类、萜类、生物碱类和甾体类化合物等,以期为生物农药的开发提供依据。  相似文献   

17.
针对华北地区旱稻产量年际不稳定的问题,利用作物生长模拟技术与数理统计相结合的方法,对华北地区气候背景下旱稻生长季内干旱风险进行了定量评估。以模型模拟的雨养条件下实际蒸散量相对于潜在条件下的蒸散量(即需水量)的亏缺率(即水分亏缺指数),以雨养条件下产量相对于潜在产量的损失率(即灾损指数)作为产量灾损强度评价指标,从受旱程度以及产量损失两个角度构建干旱风险评估模型,进行干旱风险评估。结果表明,华北地区旱稻全生育期水分亏缺指数在0.35~0.45之间,其中出苗~穗分化阶段指数值在各生育阶段中最高。干旱灾损指数变化在0.24~0.50之间,其中河北的西北部、山东北部及河南的南部较高。就干旱强度风险及灾损风险而言,空间分布趋势基本一致,风险指数低的地区主要分布在河北北部、山东南部等地区,河北中南部、河南大部等地风险指数较高;就综合风险指数而言,高值区主要分布在河南的西部和南部、山东北部以及河北中部的部分地区,低值区主要分布在北京、天津、河北北部、山东大部以及河南北部的大部分地区。总体上看,华北大部地区旱稻干旱综合风险较低,但在农业生产实际中仍不能忽视高风险区的干旱应对及防御。  相似文献   

18.
通过对定西地区战国秦长城沿线种子植物调查,共统计到种子植物58科242属444种,其中裸子植物2科3属3种;被子植物56科239属441种。单种属的科共15个,超过10属的科5个,其总属数占调查总属数的45.5%,种数占调查总种数的52.4%,以菊科最多,共38属82种。科的区系分布类型共4个正型和4个变型。属的区系分布类型共13个正型和11个变型,中国特有属2个,分布在菊科(Compositae)和伞形科(Umbelliferae)。调查区域的植物种类相对丰富;地理成分比较复杂,以温带成分占优势,以北温带分布型和旧世界温带分布型为主;发现珍稀濒危植物2种。这为保护长城选择适宜的植物类群和代表性物种提供了理论依据。  相似文献   

19.
Manual weeding of intrarow weeds in direct-sown leek and bulb onion crops grown organically can be very labour-intensive. Four field experiments, two in direct-sown leek and two in direct-sown bulb onion were made in this investigation to study the effects of physical and cultural methods on intrarow weed numbers, time consumption for hand-weeding and marketable yield parameters. The physical methods considered were: pre-emergence flaming and harrowing, and post-emergence hoeing close to the row (only leek) and vertical brush weeding. The cultural methods were: seed priming, slurry placement and cultivar choice (only leek). Generally, flaming plus brush weeding gave the highest intrarow weed control at 92% and 87%, respectively, in the two leek experiments and 39% (only brush weeding was effective) and 74%, respectively, in the two onion experiments. Time consumption for hand-weeding after the different treatments was linearly related to the remaining numbers of intrarow weeds, with no significant influences of the experimental factors on the general relationship. Generally, the cultural methods had no significant influence on the effects of physical weeding in terms of their effect against intrarow weeds. They did not affect the tolerance or robustness of the crop plants against negative impact from the physical control methods. However, generally, seed priming and cultivar choice did improve yield in the leek experiments and seed priming also did so in the one experiment with onion.  相似文献   

20.
杨桂珍  李玲 《江西植保》2004,27(2):94-96
本文介绍因特网上植物保护信息资源,包括研究进展、学术论文等相关的数据库和专业网站,供广大的植物保护科技工作者和植物保护爱好者参考使用。  相似文献   

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