防治烟蓟马的生物源农药筛选及其对解毒酶活性影响

【目的】筛选防治烟蓟马(Thrips tabaci Lindeman)的高效生物源农药,探究其对烟蓟马3种主要解毒酶细胞色素P450单加氧酶(Cytochrome P450 monooxygenase,P450)、谷胱甘肽S-转移酶(Glutathione S-transferase,GST)和羧酸酯酶(Carboxylesterase,CarE)活性的影响。【方法】以棉田采集并室内稳定饲养的烟蓟马为供试虫源,用浸叶法测定7种生物源农药对烟蓟马若虫的毒力,选择活性好的3种药剂开展田间药效试验,并在这3种生物源农药亚致死浓度(LC25)剂量处理后测定烟蓟马体内3种主要解毒酶活性。【结果】(1)7种生物源农药对烟蓟马的毒力从高到低依次为乙基多杀菌素、多杀霉素、苦参碱、印楝素、除虫菊素、鱼藤酮、藜芦碱。乙基多杀菌素、多杀霉素和苦参碱对烟蓟马的致死中浓度(LC50)分别为0.011 mg·L-1、0.274 mg·L-1、1.479 mg·L-1。(2)田间药效试验发现,每666.7 m2用2 g、4 g、6 g的60 g·L-1乙基多杀菌素悬浮剂和10 g的5%(质量分数,下同)多杀霉素悬浮剂处理,施药后7 d防治效果均在90%以上,优于1.3%苦参碱水剂和对照药剂30%噻虫嗪悬浮剂各剂量的防效。(3)LC25剂量处理烟蓟马48 h后,乙基多杀菌素处理的烟蓟马体内P450、GST和CarE活性升高,苦参碱和多杀霉素处理后CarE活性升高,噻虫嗪处理后P450和CarE活性升高。【结论】乙基多杀菌素、多杀霉素和苦参碱对烟蓟马的毒力较高,可用于防控棉田烟蓟马;CarE可能参与了烟蓟马对多杀霉素和苦参碱的解毒代谢,3种主要解毒酶可能均参与了烟蓟马对乙基多杀菌素的解毒代谢。     

河北省又取得一批植保农药类科研成果

<正>(接上期)河北省科技厅近期发布《河北省科学技术研究成果公报(2014年第一号)》,其中包括以下多项植保农药类科研成果:1.冀东玉米蓟马发生规律及防治技术研究单位名称:唐山市农业科学研究院评价单位名称:唐山市科技局课题研究明确了冀东地区玉米蓟马发生为害规律:(1)冀东地区玉米蓟马的种类为:禾蓟马、黄呆蓟马和稻单管蓟马,以禾蓟马为优势种;(2)确定了冀东地区禾蓟马的两次发生高峰,分别在5月中下旬和6月20日左右;(3)禾蓟马的为害与玉米播期以及年际间气候的变化有关。筛选出防治玉米蓟马     

注意查治芦笋蓟马

<正>芦笋蓟马为缨翅目蓟马科,为害芦笋的主要是花蓟马和烟蓟马,是刺吸性害虫,寄主极广,且为害严重。今年芦笋蓟马虫发生严重,给芦笋嫩茎及幼苗生长发育造成很大影响,笋农务必注意察看并及时防治。一、为害特点芦笋蓟马以成虫和若虫为害芦笋的拟叶、笋尖、嫩茎、鳞片、花瓣等,主要是吸食嫩茎汁液,收获的嫩茎笋尖松散,易散头,严重降低商品品质。放秧后     

芦笋蓟马须早防早治

<正>河北省2015~2016年连续两年芦笋蓟马为害严重,给芦笋嫩茎及幼苗生长发育造成很大影响,甚至毁种。一、为害特点芦笋蓟马为缨翅目蓟马科,为害芦笋的主要是花蓟马和烟蓟马,可是刺吸性害虫,寄主极广,且为害严重。芦笋蓟马以成虫和若虫为害芦笋的拟叶、笋尖、嫩茎、鳞片、花瓣等,主要是吸食嫩茎汁液。造成嫩茎发育不良,收获的嫩茎笋尖松散、弯曲畸形、极易散头,严重     

育苗阶段不同氮浓度对烟苗部分生理生化指标的影响

以红花大金元烤烟品种为材料,研究了育苗阶段不同氮浓度营养液即50、150、250、350、450、550mg/kg对成苗时烟苗农艺性状、根系活力、脯氨酸含量以及移栽后30d时体内多酚氧化酶、过氧化物酶、过氧化氢酶等活性的影响。试验结果表明：(1)当氮浓度在50~450mg/kg时,成苗时烟苗的干、鲜重随之增加,而氮浓度到550mg/kg时,烟苗的干、鲜重开始减少,说明育苗烟苗营养液浓度过低、过高均不利于烟苗的干物质的积累;(2)育苗阶段不同氮浓度营养液处理烟苗的活跃吸收面积存在极显著差异,其中以150、250mg/kg的处理为最大;(3)随着氮浓度提高,移栽时烟株体内的脯氨酸含量随之下降;(4)在移栽后30d,氮浓度为150mg/kg的处理烟株体内多酚氧化酶、过氧化物酶、过氧化氢酶活性最高,且随着氮浓度的增加而随之减少,蛋白质含量则随着氮浓度的增加而增加。综合而言,育苗阶段营养液中的氮浓度为150、250mg/kg时有利于培育抗性较强的红大品种烤烟烟苗。     

捕食螨对烟草育苗期蓟马防治效果研究

为明确捕食螨对烟草蓟马的防治效果,本文调查了云南泸西中枢育苗期蓟马发生情况及种类,并对比研究了不同捕食螨释放数量、释放方式及携带微生物菌剂的防治差异。结果表明：蓟马种类主要为西花蓟马,其次为八节黄蓟马,发生高峰期在4月中旬左右;捕食螨投放100头/盘防治效果最好;均匀撒施捕食螨对蓟马防治效果显著优于开袋放置及空白对照(P<0.05);捕食螨搭载球孢白僵菌对蓟马控制效果最好,搭载金龟子绿僵菌与不带菌相差不大,但均显著高于空白对照(P<0.05)。     

ER及其相关基因在鸡性反转胚胎中的表达

为了对鸟类性别分化中起重要作用的基因进行深入分析,对家鸡性反转胚胎雌激素及相关调控基因表达模式进行了检测,分析这些性激素在鸟类性别分化调控起到的作用。选择ER、3βHSD、P450c17、P450arom 4个基因为主要研究对象,采用外源注入formestane（福美司坦）和17β-estradiol（17β雌二醇）2种手段,并设置雌雄鸡胚2个对照组,检测以上基因在胚胎早期发育过程中(84 h、96 h、120 h、144 h、168 h、192 h)的表达变化趋势。ER、3βHSD、P450c17、P450arom基因的表达变化在注入外源激素的试验组同未注射组间,差异均显著(P＜0.05)或极显著(P＜0.01),其中ER表现为下降趋势,P450arom表达激增,3βHSD、P450c17基因表达变化缺乏明显规律。雌激素调控是一个复杂的过程,在外源激素注入过程后,原有调控模式可能会被打乱。     

棉蓟马危害趋重 应注意查治

<正>棉蓟马,也称烟蓟马、葱蓟马,属缨翅目蓟马科。除危害棉花外,还危害烟草、葱、蒜、白菜、瓜类、茄果类蔬菜、及豆科、茄科、禾本科、锦葵科等百余种作物。据笔者调查,近年来随着保护地栽培的扩大、地膜棉的推广、"3911"等剧毒农药拌棉种的停用,棉花由连片变为与瓜菜等作物插花种植,为其创造了传播危害的食物链。加之,连年大量使用农药,造成棉蓟马的天敌越来越少,导致其危害日趋加重,大田的危害盛期比上世纪末提早了15天左右     

蓟马类害虫综合治理研究进展

蓟马是缨翅目(Thysanoptera)昆虫的统称,虫体微小,常隐匿于花与嫩叶中为害。蓟马繁殖力强,世代重叠严重,爆发频次高,全球贸易和气候变暖加速了蓟马害虫的扩散和为害,蓟马类害虫已逐渐成为世界上最重要的农业害虫类群之一。国内外有关蓟马害虫的发生为害及防治方面的研究已有许多报道,但缺乏系统性归纳总结。笔者分别从蓟马生物生态学特性、发生为害现状及综合防治技术3个方面进行了综述,并对蓟马害虫的综合治理进行了展望,提出了协调使用生物防治、物理防治与化学防治,以及合理利用农业防治的综合防治技术体系是实现蓟马害虫综合治理的重要途径。     

环氧虫啶对白背飞虱的毒力随温度升高而提高

正为明确不同温度条件下白背飞虱对环氧虫啶的敏感性,华中农业大学植物科学技术学院科研人员采用稻苗浸渍法测定了在18~32℃下环氧虫啶对白背飞虱的毒力、白背飞虱蜜露量以及酯酶(EST)、细胞色素P450单加氧酶(P450)和谷胱甘肽S-转移酶(GSTs)3种解毒酶的比活力。     

不同咸水利用方式对棉花叶绿素荧光参数及土壤盐分的影响

【目的】本研究旨在科学合理地利用浅层咸水资源。【方法】依托短期定位试验开展了在第3年和第4年不同咸水利用方式下(CK:造墒和蕾期灌淡水;T1:造墒和蕾期灌咸淡混配矿化度3 g·L^-1的微咸水;T2:淡水造墒蕾期灌矿化度5 g·L^-1咸水;T3:造墒和蕾期灌矿化度5 g·L^-1咸水;T4:淡水造墒蕾期不灌水)棉花长势、叶绿素荧光参数、土壤盐分累积及其运移的变化。【结果】T1和T2处理的齐苗率、株高、干物质质量、叶面积指数、叶绿素荧光参数、产量及霜前花率与CK无显著差异,土壤盐分含量较CK有所增加,但未对棉花生长产生明显抑制。T3处理的棉花长势指标、叶绿素荧光参数较CK显著降低,0~100 cm土壤盐分含量较CK明显增加。【结论】从土壤质量安全和咸水高效利用的角度考虑,连续4年用3 g·L^-1的咸淡混合水灌溉或用淡水与5 g·L^-1的咸水轮灌不仅能节约淡水,且不影响棉花产量。本研究结果为当地在棉花生产中安全利用咸水提供技术参考。     

脱落酸对棉花体细胞胚胎发生的影响

【目的】研究脱落酸(Abscisic acid, ABA)对棉花体细胞胚胎发生过程中下胚轴脱分化和再分化的影响,优化体细胞胚胎发生体系和初步解析脱落酸调控棉花体细胞胚胎发生分子机制。【方法】以棉花品种中棉所24(CCRI 24)下胚轴为外植体,设置5个ABA浓度0、0.02、0.04、0.06、0.08μmol·L^-1,分别以A0、A1、A2、A3、A4表示,添加至MSB(MS培养基+B5维生素)培养基诱导愈伤和胚性愈伤,研究ABA对棉花下胚轴初始细胞脱分化、愈伤组织诱导和胚性愈伤组织诱导的影响。【结果】ABA促进下胚轴初始细胞脱分化;显著提高愈伤组织的脱分化率和增殖率;0.02μmol·L^-1ABA显著提高胚性愈伤分化率,0.04~0.08μmol·L^-1ABA显著降低胚性愈伤分化率。ABA处理后胚性愈伤和非胚性愈伤的增殖率均显著提高且质地受到影响。0.02~0.08μmol ABA处理下,LBD和LBD在愈伤起始期上调表达。0.02μmol·L^-1ABA处理下,在愈伤增殖早期和中期BBM、LEC1和AGL15上调表达,愈伤增殖后期FUS3、LEA、ABI3基因上调表达。【结论】脱落酸调控的棉花体细胞胚胎发生与相关标记基因的时空性表达密切相关,这些基因表达水平的增加是ABA调控愈伤和胚性愈伤分化的分子基础。     

Effects of Melatonin on the Antioxidant Enzyme Activities and Seed Germination of Cotton (Gossypium hirsutum L.) under Salt-Stress Conditions

[Objective] Cotton (Gossypium hirsutum L.) seed germination, in which melatonin plays an important regulatory role, is seriously affected by soil salinization. Cotton seed germination, antioxidant enzyme activity levels and other physiological indicators were analyzed to clarify the regulatory effects of exogenous melatonin on cotton seed germination under salt-stress conditions. [Method] The experiment was conducted in a greenhouse of Hebei Agricultural University in Baoding City, Hebei Province from 2018 to 2019 using Guoxin Cotton 9 as the material. The germination rate, germination potential, seed biomass after germination, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, as well as the malondialdehyde (MDA) content, of cotton seeds were measured after exposure to different melatonin concentrations (0, 10, 20, 50 and 100 μmol·L^－1) and 150 mmol·L^－1 NaCl treatments. [Result] After germination, the germination rate, germination potential, radical length and seed biomass significantly decreased, as did the SOD, POD and CAT activities. However, the MDA content significantly increased under salt-stress conditions. Low exogenous melatonin concentrations (10 and 20 μmol·L^－1) increased the germination potential, germination rate and biomass of cotton seeds, and promoted the elongation of radicals; however high melatonin concentrations (50 and 100 μmol·L^－1) inhibited cotton seed germination and decreased seed biomass after germination. Low melatonin concentrations (10 and 20 μmol·L^－1) increased the SOD, POD and CAT activities and decreased the MDA content in cotton seeds. [Conclusion] Low melatonin concentrations could promote germination and improve the salt tolerance of cotton seeds, while high melatonin concentrations could inhibit their germination. A 20 μmol·L^－1 melatonin concentration is appropriate for regulating cotton seed germination under salt-stress conditions.     

Applying Plant Growth Regulators at Early Stages Affects Maturation of Cotton

[Objective] Early initiation and early maturity are the foundation of high yield and good quality of cotton. The purpose of this study is to determine the effects of plant growth regulators applied at the seedling and squaring stage on the early initiation of flower bud and the rate of the opened cotton boll (ROCB) during later development period, and to provide practical measures for hastening the maturity of cotton. [Method] Several plant growth regulators were applied from cotyledonary to squaring stage under greenhouse and field conditions, water was used as the control. The first fruiting branch node (indicating the initiation of flower bud), the number of bud prior to blooming and the ROCB at mid-term of boll maturation period (23 September, 2017) were compared among treatments. [Result] Under greenhouse conditions, gibberellic acid (GA₃) applied at the cotyledonary stage with 140 μmol·L^－1 as well as the three consecutive applications of sodium nitrophenolate (CSN, 2.23 μmol·L^－1) at the cotyledonary, two-leaf and four-leaf stage made the first fruiting branch node move down by about 0.9 nodes. In field experiments, the application of gibberellin₄₊₇(GA₄₊₇, 288 and 576 μmol·L^－1) at the cotyledonary stage significantly decreased the first fruiting branch node by about 0.4 nodes. Also, the application of 6-benzylaminopurine (6-BA, 44.4 μmol·L^－1) at the three-leaf stage significantly decreased the first fruiting branch node by 0.2 nodes. However, there was no significant correlation between the first fruiting branch node and the ROCB in late September. Moreover, the application of Brassinolide (BR, 0.10 μmol·L^－1) at the bud stage increased the ROCB in late September, which was mainly associated with the increased boll set in the lower and middle fruiting branches. [Conclusion] The reasonable distribution of bolls (concentrated in the lower and middle fruiting branches as well as inner fruiting sites) is more important for the earliness of cotton than lowering the first fruiting branch node.     

Effects of Exogenous Proline on the Growth,Physiological Characteristics,and Proline Metabolism of Cotton Seedlings under Boron Deficiency Stress

[Objective] This study investigates the effects of exogenous proline on the growth, physiological responses, and proline metabolism of cotton (Ekang No.8) seedlings treated with varying boron (B) concentrations. [Method] We conducted a randomized experiment with six treatments using the hydroponic method in a greenhouse at Huazhong Agricultural University. We applied three different concentrations of boron, including 0.02 μmol·L^－1 (low-concentration B), 2.5 μmol·L^－1 (medium-concentration B), and 100 μmol·L^－1 (sufficient-concentration B). The first two are boron-deficient treatments. We also applied an exogenous proline treatment at 20 μmol·L^－1(0 μmol·L^－1 as control). When any significant difference among the treatments were observed, the related indicator was measured. [Result] The results showed that exogenous proline inhibited the growth of cotton seedlings under sufficient-concentration B treatment while promoting the absorption of B by roots under low-concentration B treatment. The application of exogenous proline to the seedlings under low-concentration B treatment reduced the contents of proline and H₂O₂ in leaves but increased the accumulation of MDA and H₂O₂ in roots. The activities of SOD and antioxidant enzymes (APX) in the roots and leaves were dramatically enhanced. Conversely, POD activity reduced significantly and there was no significant change in CAT activity relative to low-concentration B treatment. More importantly, we found that the application of exogenous proline under B deficiency increased the activities of P5CS, P5CR, OAT (synthetase), and PRODH (degrading enzyme) in proline metabolic pathways. [Conclusion] Applying exogenous proline under sufficient-B concentration inhibits growth. The application of proline to seedlings under low-B concentration promotes the absorption of B by roots, increases the activity of APX, and decreases the membrane lipid peroxidation in leaves. A B deficiency leads to proline accumulation in plants. The addition of proline under low-B concentration can reduce the proline content in leaves, which is caused by affecting the critical synthetase and catabolic enzyme activities in the proline metabolism pathway (Glu and Orn pathway). The main reason for this occurrence is the significant increase of proline dehydrogenase (PRODH) activity.     

Effects of Exogenous 24-epibrassinolide on Photosynthetic Physiology of CottonSeedlings under Low Temperature

[Objective] The objective of this study was to investigate the effects of exogenous 24-epibrassinolide (EBR) on the photosynthetic physiology of cotton seedlings under low temperature and to provide basis for improving the cold tolerance of cotton by using EBR as growth regulator. [Method] Taking CCRI 60, Lumianyan 28 and Simian 3 as materials, a field experiment was carried out in Institute of Cotton Research of CAAS(Anyang county, Henan province). Before the first low temperature treatment, the cotton seedlings were sprayed with distilled water (Control) and different concentrations of EBR (0.1 mg·L^－1 and 0.2 mg·L^－1), respectively. After 3 days, the relative electrical conductivity, chlorophyll content, rapid chlorophyll fluorescence induction kinetic curve (OJIP) and fluorescence parameters were measured. [Result] Under low temperature, the relative conductivity of CCRI 60, Lumianyan 28 and Simian 3 spraying with EBR decreased by 17.7%～32.8% compared with control, and there was no significant difference between CCRI 60 and Lumianyan 28 in different concentrations of EBR treatments, butthe relative conductivity of Simian 3 treating with 0.2 mg·L^－1 EBR was significantly lower than those treatments with 0.1 mg·L^－1 EBR . The chl a and chl b contents increased by 9.7%～32.6% and 15.0%～18.9%, respectively. The maximum photochemical efficiency of photosystemⅡ (F_v/F_M) and photosynthetic performance index on absorption basis(PI_ABS) increased significantly. PI_ABS of CCRI 60 increase the maximum by 75.6% using 0.1 mg·L^－1 EBR. Lumianyan 28 and Simian 3 increased the maximum by 101.1% and 265.6% using 0.2 mg·L^－1 EBR, respectively; Absorbed photon flux per cross section (ABS/CSm), electron transport flux (further than QA) per active reactive center (ETo/RC) and probability for electron transport (φEo) are significantly increased. [Conclusion] Exogenous EBR can enhance the ability of low temperature tolerance of cotton seedlings and alleviate the inhibition of photosynthesis in cotton at low temperature. The study showed that 0.1 mg·L^－1 EBR performs well in CCRI 60 and 0.2 mg·L^－1 in Lumianyan 28 and Simian 3.     

A Regeneration System for Cotton Variety Xinluzao 45 via Somatic Embryogenesis

[Objective] The purpose of this study was to expand upland cotton genotypes suitable for regeneration via somatic embryogenesis, so as to provide excellent receptor materials for the genetic transformation of cotton. [Method] Six different hormone combinations were studied to establish a somatic embryo regeneration system for hypocotyl explants of Xinluzao 45, a widely planted variety in Xinjiang Province. [Result] Faint yellow callus was induced on a medium consisting of hormone combinations C1 (0.1 mg·L^－1 acetic acid dichlorobenzene oxide [2, 4-D] + 0.1 mg·L^－1 kinetin [KT]) or C5 (0.1 mg·L^－1 2, 4-D + 0.5 mg·L^－1 indo-3-butyric acid + 0.1 mg·L^－1 KT). The generated callus was able to successfully induce embryogenic callus on hormone-free medium containing doubled KNO3. The embryogenic callus then developed into somatic embryos and regenerated plants. Maximum rates of callus induction and regeneration were 92.2% and 40.3%, respectively. Although no significant difference was observed in the rate of callus induction of Xinluzao 45 hypocotyls between hormone combinations C1 and C5, the incidence of induced embryonic callus was higher on C1 than on C5. [Conclusion] The somatic embryo regeneration system developed in this study provides technical support that will facilitate Agrobacterium-mediated transformation of upland cotton Xinluzao 45.     

Cotton Chemical Topping by Applying DPC in Different Cotton-Growing Regions

[Objective] The objective of this study was to investigate the stability and universality of cotton chemical topping by applying mepiquat chloride (1,1-dimethyl-piperidinium chloride, DPC) in different cotton-growing regions. [Method] Field experiments were conducted in 2018 at 10 locations in the Yellow River basin (Hejian and Handan, Hebei province; Dezhou and Wudi, Shandong province), the Yangtze River basin (Dafeng, Jiangsu province; Huanggang, Hubei province), and Xinjiang area (Shihezi location I and loacation II, northern Xinjiang and Luntai and Shaya, southern Xinjiang). Local cultivars/lines were used, and the experiments were performed using a randomized complete block design with three or four replicates. Accompanied with typical DPC multi-application in each location, chemical topping was conducted at 10 days before manual topping (T1) or at the same time with manual topping (T2) by applying four dosages of DPC (0, 90, 180, 270 g·hm^－2), manual topping was used as the first control and non-topping as the second control. [Result] The time of chemical topping significantly affected cotton plant height (except for the results in Handan, Dezhou and Wudi) and the number of fruit branches (except for the results in Dafeng and Huanggang). It was observed that earlier chemical topping would result in lower cotton plant height and a fewer fruit branches. In Hejian and Shihezi location I, the average plant height across DPC chemical topping at T1 stage was not only lower than that of T2 stage but also 3.3 cm and 4.6 cm lower than that of manual topping, respectively. In most locations, chemical topping at T1 stage increased around two fruit branches per plant compared with manual topping, while in T2 stage the increased fruit branches per plant ranged from 2.3 to 7.7. Also, we found that a higher dosage of DPC resulted in shorter plant height (except for that in Huanggang). In some locations, plant heights of chemical topping with 180 g·hm^－2 or 270 g·hm^－2 DPC were even shorter than that of manual topping. The number of fruit branches per plant of 0 g·hm^－2 DPC increased by 2.4-8.3 compared with manual topping. However, chemical topping with 90-270 g·hm^－2 DPC significantly reduced the number of fruit branches compared with 0 g·hm^－2 DPC. There were no significant differences in the number of fruit branches among three DPC dosages (90, 180, and 270 g·hm^－2). In Handan, seed cotton yield of chemical topping at T2 stage was significantly lower than that of manual topping due to the decreased boll number, which is possibly associated with the high temperature and drought weather after chemical topping. While at other locations, most treatments of chemical topping by using DPC did not produce significant effects on yield. In addition, chemical topping by using DPC did not delay cotton maturity, characterized by their similar boll-opening rate and the first harvest rate to those of manual topping before spraying harvest aids. [Conclusion] Cotton chemical topping with DPC is more stable and universal across different cotton-growing regions. We suggest that 90-180 g·hm^－2 DPC could be used at the same time with manual topping for cotton chemical topping.     

江苏滨海盐碱地麦后直播棉氮、磷、钾肥料优化配比研究

【目的】建立江苏省滨海盐碱地麦后直播棉合理的施肥技术体系。【方法】2017―2018年在江苏省滨海棉田,以中棉所50为材料,采用正交设计,研究了不同氮、磷、钾肥配施量对棉花生物量、养分累积与利用及产量的影响。【结果】氮、磷、钾肥3因子对棉株地上部和生殖器官生物量、棉株地上部氮和钾素累积量及皮棉产量的影响均为氮肥>磷肥>钾肥。施N 150~225 kg·hm-2、P2O575 kg·hm-2下棉株地上部和生殖器官生物量、氮和钾累积量及皮棉产量较高。钾肥因子对生殖器官生物量和皮棉产量影响不显著。钾肥因子对氮、钾素利用效率的影响大于氮肥和磷肥,氮肥因子对磷素利用效率的影响大于磷肥和钾肥,施K2O 75~150 kg·hm-2氮、钾素利用效率较高、施氮225 kg·hm-2磷素利用效率较高。土壤碱解氮、速效磷、速效钾含量较高棉田的氮、磷(P2O5)、钾(K2O)肥配施量分别为225 kg·hm-2、75 kg·hm-2和150~225 kg·hm-2。相关分析表明,皮棉产量与棉株氮、钾素累积量显著正相关。【结论】长江流域棉区滨海盐碱地麦后直播棉利于产量和养分利用效率提高的最佳氮、磷(P2O5)、钾(K2O)肥配施量分别为225 kg·hm-2、75 kg·hm-2、75 kg·hm-2。     

Effects of Planting Density and Chemical control on Yield and Mineral Elements Accumulation of Cotton Direct-Seeded after Wheat

[Objective] The effects of planting density and Miantaijin treatment on yield and nitrogen, phosphorus and potassium uptake and accumulation in cotton direct-seeded after wheat in the Yangtze River basin were studied in order to clarify the high-yield cultivation techniques under this cropping system. 【Method】 In 2011 and 2012, Guoxinzao 11-1 at the experimental material, and adopted three densities (75 000, 90 000 and 105 000 plants·hm^－2) and three Miantaijin doses (0 mL·hm^－2, 1 170 mL·hm^－2 and 2 340 mL·hm^－2). 【Result】 The results showed that the highest yield was 3 551.3～3 687.5 kg·hm^－2 under 90 000～105 000 plant·hm^－2 density combined with 1 170 mL·hm^－2 Miantaijin (seedling stage: 90 mL·hm^－2, peak squaring stage: 180 mL·hm^－2, peak flowering stage: 360 mL·hm^－2, peak boll-setting stage: 540 mL·hm^－2). Under these conditions, the highest uptake of nitrogen, phosphorus and potassium was 117.8 kg·hm^－2, 77.4 kg·hm^－2, 116.4 kg·hm^－2, respectively. Among them, nitrogen uptake was the highest in the peak-squaring stage to peak-flowering stage, while the highest phosphorus and potassium uptake were both detected in the peak-flowering to boll-opening stage. The correlation analysis showed that there was a significant linear positive correlation between the yield of direct seeded cotton after wheat and the total absorption and accumulation of nitrogen, phosphorus and potassium, especially during the peak flowering to boll-opening stage. 【Conclusion】 The suitable application dose of Miantaijin under medium and high density could enhance the absorption of nitrogen, phosphorus and potassium in the whole growth period of cotton, especially in the peak flowering to boll-opening stage. and thus result in the high yield of direct-seeded cotton after wheat in the Yangtze River basin.