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加入WTO与我国新疆棉区棉花生产应对措施 总被引:1,自引:0,他引:1
通过对WTO有关棉花条款的分析,探讨了在中国加入WTO后新疆棉区棉花生产所面临的问题,提出了新疆棉区棉花生产的应对措施。 相似文献
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采用ELISA检测和室内生物测定方法,测定6个转Bt基因棉花品种(系)不同生育期叶片中的Bt毒蛋白含量及其对各世代棉铃虫的抗性水平。转Bt基因棉花叶片中的Bt毒蛋白含量总体上随着棉花生育期的推进而逐渐下降,6个品种(系)叶片的Bt毒蛋白含量子叶期最高,达1 210.03~1 733.15 ng/g,与子叶期相比,三叶期、七叶期、盛蕾期、花铃期、吐絮期Bt毒蛋白含量减少幅度为2.5%~96.0%。6个品种(系)对第4代棉铃虫幼虫抗虫性较低,毒杀效果仅为19.0%~41.3%。幼虫的校正死亡率逐代下降,各棉花品种对第4代幼虫的校正死亡率仅为12.0%~36.2%。 相似文献
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科学测定土地流入对棉花生产的影响,识别棉花适度经营规模范围,对推进土地流转和确保棉花产业安全具有重要意义.文中基于新疆棉花主产区591份棉花种植户的微观数据,利用倾向值匹配法测算了土地流入对棉花生产的影响.结果表明:考虑样本农户自选择和内生性问题后,土地流入使籽棉亩产量平均提升29.20kg;在现有的技术水平下,棉花种... 相似文献
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The metabolic fate of the 14C-labeled herbicide, 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (bioxone), in cotton (Gossypium hirsutum L. “Acala 4-42-77”) was studied using thin-layer chromatography, autoradiography, and counting. Bioxone-14C was readily metabolized by cotton tissue to 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU) and 1-(3,4-dichlorophenyl)urea (DCPU). Leaf discs metabolized bioxone-14C rapidly; 12 hr posttreatment, 65% of the 14C in methanol extracts was in forms other than intact herbicide. Excised leaves treated through the petiole with either heterocyclic ring-labeled or phenyl ring-labeled herbicide contained little bioxone-14C after 1 day; DCPMU was formed early then decreased with time. DCPU accounted for 55–70% of the 14C in excised leaves 3 days posttreatment. In intact plants treated via the roots, the herbicide was rapidly metabolized in the roots to DCPMU and DCPU; little or no intact herbicide was translocated to the leaves. Little radioactivity accumulated in the roots with time; the radioactivity in the leaves accounted for 80–90% of the methanol-soluble 14C 47 days posttreatment. Most of the 14C in the leaves was recovered as DCPU (50–60%) and unidentified polar metabolite(s) which remained at the origin of the thin-layer plates (30–40%). The percentage of radioactivity which remained in cotton residue after methanol extraction increased with time. Digestion of the plant residues with the proteolytic enzyme pronase indicated that some of the nonextractable 14C may be DCPMU and DCPU complexed with proteins. Similar metabolic patterns were noted after treatment with either heterocyclic ring-labeled or phenyl ring-labeled bioxone-14C. Generally, bioxone was metabolized to DCPMU which in turn was demethylated to DCPU. The herbicide and DCPMU were 20 times as toxic as DCPU to oat (Avena sativa L.), a susceptible species. 相似文献
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以新陆中75号、新陆中54号、新海35号和新海48号为材料,研究陆地棉与海岛棉在相同管理条件下干物质积累与氮素吸收分配的特点。结果表明:陆地棉干物质积累总量在全生育期内均高于海岛棉,生殖器官干物质所占比例在生育前期小于海岛棉,后期逐渐大于海岛棉;氮素积累总量在全生育期内陆地棉均大于海岛棉,生殖器官氮素积累比例在生育前期为陆地棉小于海岛棉,后期逐渐大于海岛棉。与陆地棉相比海岛棉营养器官干物质以及氮素积累比例较大,不利于生育后期生殖器官干物质的积累与分配,从而影响棉花产量。因此,在大田管理中应注意在生育后期加强对海岛棉的水肥管理。 相似文献
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植物内生细菌在棉花体内的定殖动态及对棉花黄萎病的生物防治效果 总被引:2,自引:3,他引:2
为明确植物内生细菌在棉花体内的定殖规律及对棉花黄萎病防治效果的影响,采用对峙培养法筛选对大丽轮枝菌Verticillium dahliae Kleb.抑菌活性强的植物内生细菌,通过形态及生理生化特征并结合16S r DNA和gyr B基因分析鉴定菌株;利用抗生素标记法及盆栽试验研究其在棉花体内的定殖动态及对棉花黄萎病的防治效果。结果表明:共筛选到3株对大丽轮枝菌具有强抑菌活性的菌株SZ5、DP10和CCM9,其中SZ5为蜡样芽胞杆菌Bacillus cereus,定殖在棉花根部、茎部和叶部,DP10和CCM9为枯草芽胞杆菌B.subtilis,定殖在棉花根部和茎部,3株菌在棉花根部的定殖数量均在10~3CFU/g以上;棉花苗沾根分别接入3株内生细菌10 d后再接种大丽轮枝菌孢子悬浮液,对棉花黄萎病的防治效果达79.52%~89.79%,而3株内生细菌沾根接种后立即移栽到含有大丽轮枝菌的土壤中对棉花黄萎病的防治效果为23.77%~36.03%。表明不同内生细菌菌株在棉花体内的定殖规律不同;且在棉苗中定殖一定数量后,才能对棉花黄萎病产生较高的防治效果。 相似文献
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通过对新和县1999、2002两年冬季铲除田埂杂草带棉田棉花卷叶率变化情况的观测,研究铲除田埂杂草对棉砾的防治效果。结果表明:苗期、蕾期防治效果可以达到70%~90%,棉花卷叶率下降3.35~16.83倍(P<0.05)。棉蚜越冬和早春迁飞与田埂上的杂草有关可能是这项技术有效的原因。 相似文献
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棉蚜在不同棉花品种上的着落量和种群数量的研究 总被引:4,自引:0,他引:4
通过田间调查棉蚜种群数量和网罩棉苗测定其不选择性,采用Duncan’s多重极差检验的数据分析方法,对棉蚜在不同棉花品种上的着落量和种群数量进行了研究。结果表明:棉蚜对8个棉花品种具有不同的选择性。对徐州142、鄂棉6号表现为明显的不选择性,对33B、SGK抗虫棉、新高抗5号的选择性较强;棉蚜在8个供试品种上的种群数量差别明显,徐州142和鄂棉6号上的蚜量远远低于33B、新高抗5号和SGK抗虫棉;同一季节不同棉花品种上的蚜量增长速率不同,33B、新高抗5号和SGK抗虫棉上蚜量增长速率明显较快。在相同的棉花生长阶段,33B、新高抗5号和SGK抗虫棉的蚜害指数明显高于其它供试棉花品种。 相似文献
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噻虫嗪在棉花和土壤中的残留动态研究 总被引:5,自引:0,他引:5
采用超高效液相色谱一电喷雾串联质谱法测定噻虫嗪和高效氯氟氰菊酯·噻虫嗪混剂中噻虫嗪在棉叶和土壤中的残留.结果表明,噻虫嗪在土壤中平均回收率为88.8%~97.9%,变异系数为3.1%~6.2%;噻虫嗪在棉叶中的平均回收率为84.4%~95.8%,变异系数为1.3%~5.2%.噻虫嗪在棉叶和土壤中的消解动态表明:噻虫嗪在棉叶中的降解比在土壤中快,单剂中噻虫嗪在山东省和河南省两地土壤中的消解半衰期分别为2.9d和4.8d,棉叶中的消解半衰期为1.4d和1.9d.混剂中的噻虫嗪在山东省和河南省两地棉叶中的消解半衰期分别为1.4d和1.6d. 相似文献
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Shoshana Yathom 《Phytoparasitica》1989,17(4):327-328
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M. Broza 《Phytoparasitica》1986,14(1):81-85
The aphidAphis gossypii was previously known as a minor pest in cotton fields in Israel and it usually disappeared toward mid-season. At the end of 1983 and throughout the 1984 season an outbreak ofA. gossypii occurred in cotton fields. Aphids became the primary pest in 1984 and up to 80% of the pesticide treatments were directed against them in some cotton areas. The population returned to its normal level in 1985, but the aphids continued to appear throughout the season, rather than being an early season pest. 相似文献
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A whitefly (Bemisia argentifolii) resistance crisis climaxed in 1995 in Arizona cotton and prompted the development of an integrated resistance management strategy adapted from a program implemented in Israel in 1987. The strategy incorporated two new major elements: once-per-year use of the insect growth regulators (IGRs) pyriproxyfen and buprofezin, and measures to delay use of pyrethroids for as long into the growing season as possible. A three-stage chemical use recommendation was formulated comprising IGRs (Stage I), other non-pyrethroid insecticides (Stage II), and synergized pyrethroid insecticides (Stage III). Results from use of the strategy in the 1996 season were very promising. Insecticide use for control of whiteflies was reduced substantially. State-wide monitoring of whitefly susceptibility revealed significant reductions in resistance to synergized pyrethroids as well as increased susceptibility to amitraz. Susceptibility of Lygus bugs to key insecticides changed correspondingly with increases and decreases in whitefly resistance from 1994 through 1996. ©1997 SCI 相似文献
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湖南省棉田杂草调查 总被引:4,自引:0,他引:4
对湖南省棉花主产区棉田杂草的种类、发生规律及化学除草情况进行了调查。结果发现, 湖南省棉田常见杂草包括12科, 28种, 其中禾本科杂草占25.00%, 阔叶杂草占67.86%, 莎草科占7.14%; 一年生杂草占78.57%, 多年生杂草占21.43%。相对多度10%以上的杂草有7种, 其中马唐、牛筋草、千金子、铁苋菜、小飞蓬5种杂草为湖南省棉田杂草的优势种, 相对多度分别为37.79%、33.64%、29.15%、26.23%、23.83%。杂草发生呈现3个高峰期, 分别为5月下旬, 6月中下旬, 7月下旬至8月初, 杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法。 相似文献