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一直以来，棉株早衰是困扰广大棉农的一个重要问题，也是制约我国很多地方棉花生产发展的一个主要因素。棉株早衰表现为：棉株进入盛铃后期，叶片变黄，继而逐步变为褐色，直至枯萎而自动脱落；出现很明显的尖顶，90％呈红茎；顶部不再延伸新的果枝，蕾小、花弱、桃少；根部根系衰竭，根浅根少，吸肥吸水能力大大下降。 相似文献
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湖南省桃源县棉花早衰的原因及预防措施 总被引：1，自引：0，他引：1
近几年来,湖南省桃源县棉花早衰、枯死现象常有可见,并有逐年加重发展趋势,严重影响了棉花产量与品质.主要表现症状为棉株长势较弱,上部果枝不能伸展,蕾黄且小,花铃弱小,脱落严重,叶片过早变黄而脱落,根表皮腐烂,棉桃未熟早开,甚至全株枯死.因此,棉花早衰已成为严重困扰桃源县棉农增产增收的不利因素,是农业生产中的一大损失,不得不引起高度重视. 相似文献
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中棉所29早衰原因与防治措施 总被引：1，自引：0，他引：1
中棉所 2 9是我国个通过国家审定的第一个转基因抗虫棉 ,该品种高产、优质、抗虫、抗病 ,推广面积逐年扩大 ,但在大田生产上会发生早衰现象。究其原因 ,大都由栽培不当引起。因此 ,探讨中棉所 2 9防早衰措施 ,以充分发挥其优良种性 ,显得很有必要。1早衰表现棉株根系和叶片的功能过早衰退 ,营养生长衰退较早 ,地上部表现为叶片变黄、脱落多 ,上部果枝不能伸展 ,蕾小而黄 ,花弱铃小、脱落多 ,严重时棉株干枯。2早衰对产量与品质的影响根据早晚与严重程度不同 ,一般减产 1 0 %～2 0 % ,严重的甚至达到 30 %。对棉花的纤维长度、比强度及麦克隆… 相似文献
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为分析棉花早衰的原因及表现、总结棉花高产栽培经验,对2014年河北威县3块早衰棉田的土壤养分状况、棉花生长情况和产量进行调查分析。分析表明:棉田起土、复耕棉田由于起土或持续失耕造成土壤氮磷钾和有机质等养分含量明显降低导致棉花早衰;前茬为苜蓿的棉田由于苜蓿的固氮作用,土壤氮磷钾和有机质等养分含量明显增加,能够减缓棉花早衰的发生。棉花早衰在冠层上表现为株高降低、棉株变细、叶绿素含量降低、果节数减少和最长果枝长度减小等方面,根系上表现为主根长和最长侧根长度变短、侧根数目变少,与相应对照棉田相比,本调查早衰棉田棉花主根长度和最长侧根长度分别降低9.7%和31%,一级侧根数减少36.4%。早衰棉花产量明显降低,主要原因是早衰棉花单株成铃数和铃重降低,起土棉田、复耕棉田和前茬棉花棉田棉花理论产量与相应对照棉田相比分别低29.3%,13.2%和4.3%。本调查说明土壤养分状况变差是造成棉花早衰的主要原因,棉田持续耕作可能造成棉花早衰。 相似文献
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棉花吐絮期是指棉铃开始吐絮直至收花结束称为吐絮期。南方棉区一般从8月下旬开始吐絮,11月上旬收花完毕,大约70～80天时间。吐絮期棉田管理主要问题表现在以下三个方面:1 棉花早衰棉花早衰是指棉株过早的停止生长,没有达到预定的果枝数或者上部果枝伸不开,在一定的密度和适宜生长季节内,未能充分发挥个体的增产潜力。棉株早衰,主要原因是受较长时间干旱、缺肥、病虫危害或棉区附近工厂及砖瓦窑排出的有害气体多种因素所造成。怎样确保棉花稳产高产,在生产中解决棉花早衰这一矛盾,主要措施有:首先,吐絮期,如遇干旱,要及时、适量进行灌溉,保… 相似文献
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2002年兴化市棉花大面积早衰原因及防治措施 总被引：3，自引：0，他引：3
兴化市植棉历史悠久 ,植棉水平较高 ,近年来全市棉花单产水平一直稳定在每公顷 1 2 0 0 kg以上。但是由于棉花早衰发生面积及程度呈逐年上升趋势 ,已成为棉花产量、品质和综合经济效益进一步提高的障碍因子。防止棉花早衰已是本市棉花栽培及棉田管理的重点研究内容。1棉花早衰的特点2 0 0 2年棉花早衰发生面积占棉田面积近30 %。一般在 9月中旬即开始表现 ,部分田块甚至在 8月下旬到 9月上旬就表现早衰症状 ,9月中旬叶片大量脱落 ,全棉田棉株只剩光秆和棉铃。棉花早衰有黄化型、红叶型和青枯型等三种类型 ,其中黄化型占早衰面积的 2 3.5 % ,… 相似文献
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该品种由天宁种业有限公司用ZM30×ZM12杂交,经多代连续选育而成的高产大铃、抗虫抗病棉花新品种,2004年经河南省农作物品种审定委员会审定通过。1特征特性生育期130天,植株呈塔形,株高100?,果枝节位6~8个,叶片浅绿色。铃卵圆形,早熟不早衰,芽果多疯杈少,结铃性强而集中,抗旱抗涝脱落少,铃重5.5~6g,平均单株成铃30~35个,最高可达90个。吐絮畅且洁白,易收摘,衣分38%~40%,子指10g,霜前棉占90%以上。经中国农科院棉花研究所2001-2002年抗性鉴定:高抗枯萎病,病指2.3;高耐黄萎病,病指22.9。适应黄淮流域、长江部分流域及新疆地区种植。2纤维品… 相似文献
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针对豫北地区的大豆生产现状，从气候、土壤、品种、生态因素及市场需求等方面提出了优质大豆的发展策略与途径。 相似文献
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Sena L.P. VanderJagt D.J. Rivera C. Tsin A.T.C. Muhamadu I. Mahamadou O. Millson M. Pastuszyn A. Glew R.H. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1998,52(1):17-30
In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply. 相似文献
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通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT50)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。 相似文献
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1 吉林省平安农业科学院大豆研究工作简介吉林省平安农业科学院大豆研究所 ,设在吉林省长春市西安大路种子大厦内。现有科技人员 6人 ,其中研究员 2人 ,农艺师 2人 ,技术员 2人 ,定向培养研究生 2人。大豆研究所的主要任务是选育稳产、高产、优质及抗病虫大豆新品种 ;同时密切 相似文献
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Irrigation of Netted Gem potatoes was scheduled during three growing seasons by three methods: (a) when plants displayed first visual symptoms of moisture stress, (b) when indicated by a soil moisture budget involving estimated evapotranspiration, and (c) on the basis of tensiometer readings of soil moisture suction. When the tensiometer method of scheduling was used, the mean yields of tubers were 55.0 and 25.8 cwt/acre (6160 and 2890 kg/ha) higher than those obtained with the other two scheduling methods. Methods did not affect the specific gravity of potatoes. Method (a) scheduled irrigations least frequently. Scheduling by the budget method was not always adequate because it was based on the assumption that the crop extracted water from a constant 4 ft (1.2 m) profile from planting to full vegetative growth. In one year the budget method scheduled the first irrigation earlier than necessary and delayed the second irrigation during a critical period of crop growth. From full vegetative cover to harvest the irrigation schedules were alike for both the budget and tensiometer methods. 相似文献
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以长沙县高桥相同嫩度茶鲜叶原料采用卷曲形毛尖茶加工工艺制绿茶为对照,分别对沅陵县齐眉翠峰、凤娇碣滩茶、干发茶和军大坪茶4种绿茶的主要生化成分与感官品质进行初步分析。结果表明,沅陵4种绿茶的茶多酚总量28.76%~30.34%,游离氨基酸总量2.35%~3.22%,咖啡碱含量3.00%~3.63%,水浸出物含量37.26%~40.07%,可溶性糖总量5.46%~5.65%,可溶性蛋白含量1.50%~1.74%,类黄酮化合物总量1.16%~1.79%,叶绿素总量1.36%~2.01%,儿茶素总量13.53%~16.20%。与对照相比,4种绿茶的茶多酚、可溶性糖和儿茶素总量均高于对照,除齐眉翠峰外其余3种茶样水浸出物和叶绿素总量均高于对照,除干发茶外其余3种茶样类黄酮化合物总量均高于对照。 相似文献
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M. D. Harrison Gestur Johnson R. D. Barmington 《American Journal of Potato Research》1970,47(10):386-393
A broadcast application of PCNB (Terraclor) resulted in a reasonably uniform distribution of the chemical in the soil with the concentration decreasing in a linear fashion with increasing depth in the soil profile. A banded application resuluted in a considerably higher chemical concentration at the 4–6 inch depth than at the 0–2 or the 2–4 inch depths. The problem of the lack of uniformity of chemical distribution could probably be solved by altering nozzle placement and size and allow use of the band method of application to minimize grower cost. More complete disking in the case of the broadcast treatment would probably result in a relatively uniform distribution of the chemical but at higher cost to the grower. PCNB application rates of 10, 15 and 25 lbs per acre broadcast and 71/2, 10 and 121/2 lbs per acre in a band significantly reduced the severity ofRhizoctonia infection of Russet Burbank potatoes but did not increase potato yields significantly. 相似文献
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P. Mésochina W. Martin-Rosset † J.-L. Peyraud ‡ P. Duncan § D. Micol† S. Boulot¶ 《Grass and Forage Science》1998,53(2):189-196
Data from in vivo digestibility trial with four to six horses fed twenty-seven forage-based diets are used to calculate prediction equations for the digestibility of dry and organic matter, based on the crude ash (CA), crude protein (CP) and crude fibre (CF) contents of diets and faeces. The most precise prediction of dry-matter digestibility (r.s.d. = 0.032, R2= 0.80) was derived from a multiple regression including faecal (CP, CF) and dietary parameters (CF). Among faecal parameters, CP was the best single predictor of both digestibility (r.s.d) = 0.040, r2= 0.63) and dietary CP content (r.s.d = 0.028, r2= 0.59). For biological reasons we propose a non-linear model that allows prediction of dry- and organic-matter digestibility from faecal CP Content with reasonable Precision (r.s.d = 0.038, 0.036, r2= 0.65, 0.74, respectively). This will be adequate for many studies, especially for free-living animals in rangelands. 相似文献
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橡胶树丛枝病病原的抗血清制备与应用 总被引：5，自引：1，他引：4
以感染橡胶树丛枝病病原的长春花为材料,制备得到橡胶丛枝病病原菌抽提液,以抽提液为抗原免疫家兔,制备抗血清,经微量沉淀测定,抗血清效价为１：２０４８。应用橡胶丛枝病抗血清检测橡胶褐皮病,无症苗木检出率达３０％－３７％,可疑的褐皮病树检出率达８５．７％。 相似文献