株型对棉株14C同化物生产及运转分配的影响

运用 14 C示踪技术 ,研究了简化整枝与早打主茎顶心、少留果枝改变株型对 14 C同化物生产分配的影响。结果表明 ,简化整枝蕾期、花铃期果枝叶的光合作用强度和14 C同化量均低于对照 ,且　14 C同化物向主茎和果枝的分配比例也较对照降低。简化整枝早打主茎顶心 ,可提高花铃期果枝叶、叶枝叶的光合作用强度和 14 C同化物向叶枝的分配比例。反映到产量和产量构成因素上 ,表现为简化整枝主茎结铃减少 ,叶枝结铃可弥补其损失 ,单铃重和衣分略有降低 ;简化整枝早打主茎顶心增加了叶枝结铃数 ,且单铃重和衣分略有提高。但处理间的皮棉产量均无显著差异     

留营养枝棉花群体干物质积累分配规律研究

研究结果表明,留营养枝对棉花叶和生殖器官的干物质积累分配无显著影响,但影响主茎的生长,使主茎干物质积累量减少;早打主茎顶心促进营养枝的生长,群体总干物质积累量增加。从产量构成因素分析,留营养枝棉花主茎果枝结铃数量减少,平均单铃重略有降低,但由于叶枝结铃可以弥补主茎结铃损失,群体总结铃数加有增加,皮棉产量与对照无显著差异;留营养枝早打主茎顶心,营养枝结铃数量增加,单铃重降低,但衣分提高,对群体铃数及皮棉产量无显著影响。     

Response of Upland Cotton (Gossypium hirsutum) to Fruiting Branch Removal

Cotton response to fruiting branch removal (FBR) is critical information in estimating plant recovery potential and making management decisions after hail storms or other physical damages. Fruiting branches were removed at first bloom (R8), 2.5‐cm boll (R12) and peak bloom (R16) growth stages. Five FBR treatments were conducted at each of the above three growth stages: 0 %, 25 %, 50 %, 75 % and 100 %. At harvest, five plants were randomly chosen from each plot and branches separated into three groups: vegetative, lower and upper fruiting branches. Lower fruiting branches were from the nodes where FBR treatments were conducted, whereas upper fruiting branches were the new branches developed after FBR. Seed cotton weight, open boll number and node number in each group were recorded. Fruiting branch removal increased boll number, boll size and boll/node on the upper fruiting branches, which compensated yield loss on lower fruiting branches. Generally, FBR at the first bloom reduced cotton yield more than it did at the 2.5‐cm boll and peak bloom growth stages when FBR percentage was lower than 75 %. The removal of all 16 fruiting branches at peak bloom reduced cotton yield by 16.8 %, indicating remarkable compensation ability by cotton plants in climates with a long growing season.     

留叶枝去早果枝对抗虫棉生长发育及产量的影响

为探索留叶枝去早果枝对抗虫棉生长发育和产量的影响，于2004—2005年以两个不同熟性的抗虫棉品系K640和K9918为材料，在济南和临清进行了留叶枝去早果枝试验研究。结果表明，与正常整枝（去叶枝）相比，留叶枝去早果枝显著促进了两个品系的株高增长和叶面积扩展，叶面积系数提高了24%~94%。早熟品系K640在2004年和2005年分别比正常整枝增产7.4%和15.6%，而中早熟品系K9918的产量在2004年与正常整枝相当、2005年减产12.0%。留叶枝去早果枝显著减少了伏前桃比例，而相应提高了伏桃和秋桃的比例。留叶枝去早果枝对平均衣分影响不大，但显著影响铃数。分析认为，留叶枝去早果枝对棉花生长发育和产量的效应主要是通过提高叶源、降低库源比实现的，只有在叶源相对不足的情况下采取该措施才有增产作用。     

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.     

Low Incident Light Combined with Partial Waterlogging Impairs Photosynthesis and Imposes a Yield Penalty in Cotton

Through field studies, cotton responses to dual stresses – waterlogging and low light (shade) were investigated. The hypothesis was that shade would amplify yield losses in waterlogged (WL) cotton. Either early or late in the reproductive phase, the crop was WL (96 h and 120 h, in 2012–2013 and 2013–2014, respectively) and/or shaded (6 days or 9 days in 2012–2013 and 2013–2014, respectively). Waterlogging at early reproductive phase significantly reduced lint yield (17 % averaged across both years) of cotton, although shade‐induced yield losses (18 %) were only significant in 2013–2014. Shade significantly exacerbated yield losses only when the impact of waterlogging damage was modest (2013–2014). More intense waterlogging impaired lint yield independently of the light levels. Yield reductions in these experiments were the consequence of both accelerated fruit abscission and fewer fruiting nodes produced. Plants had lower leaf nitrogen levels and photosynthetic rates after waterlogging and/or shade treatments and produced fewer fruiting nodes. Although long‐term shade increased specific leaf area (30 %) and leaf N (20 %) immediately following 5 days of waterlogging, it did not restore shoot growth, node formation or lint yield because of suppressed photosynthetic performance (area basis) and carbohydrate supply.     

种植密度和缩节胺调控对麦后直播棉产量和冠层特征的影响

2013―2014年以早熟棉(中棉所50)为材料,采用裂区设计,在江苏省南京市研究了种植密度(7.50万、9.75万和12.00万株·hm~(-2))和缩节胺(DPC)调控(0,52.5和105.0 g·hm~(-2))对麦后直播棉产量和冠层特征的影响。结果表明:皮棉产量在不同种植密度下以12.00万株·hm~(-2)处理最低,在不同DPC用量水平下以0 g·hm~(-2)处理最低;种植密度与DPC调控存在互作效应,以种植密度9.75万株·hm~(-2)、DPC用量52.5~105 g·hm~(-2)处理产量较高,且产量构成中以铃数对产量的直接效应最大。对冠层特征影响表明,下部果枝夹角和长度随种植密度增加而降低,而中、上部果枝的夹角和长度、叶面积指数均以种植密度9.75万株·hm~(-2)处理较高;不同部位果枝夹角和长度、叶面积指数均随DPC用量增加而降低,而透光率则相反。相关分析表明,下部果枝夹角大、中部果枝较长及上部果枝夹角小且叶面积指数和透光率较高,有利于提高产量和霜前花率。综上,该棉区麦后直播棉种植密度9.75万株·hm~(-2)、DPC用量52.5~105 g·hm~(-2)(蕾期、开花期和打顶后用量比例为1∶2∶4),有利于改善棉花冠层特征,实现早熟高产。     

Effect of Two Row Spacings and Hemp Sesbania Competition on Sunflower

The competitiveness of hemp sesbania ( Sesbania exaltata [Raf.] RYBD. EX A. W. Hill) with sunflower ( Helianthus annuus L.) grown in two row spacings was evaluated at the University of Arkansas at Pine Bluff Agricultural Experiment Station in 1982 and 1983. Sunflower and hemp sesbania at densities of 3 to 5 and 13 to 16 plants per meter row, respectively, were interseeded in 61 and 91 cm row spacings in field test plots. Hemp sesbania plants were removed at different sunflower growth stages. In 1982, weed removal treatments were: (1) weedy check, (2) weed-free check, (3) weed removal at 15-leaf stage, (4) removal at 20%, (5) 50% and (6) 100% sunflower anthesis. Treatments in 1983 consisted of: (1) weedy check, (2) weed-free check, (3) weed removal at 10-leaf stage, (4) bud stage, (5) pre-anthesis, (6) 10% anthesis, and (7) 100% anthesis. Sunflower yields were significantly decreased by hemp sesbania competition each year, except for the weed competition treatments in 91 cm row spacing in 1982. Generally, the longer the weeds were allowed to compete with sunflower, the greater the sunflower yield reduction. Yield reductions of 5% to 6% and 25% or more were observed when hemp sesbania was allowed to compete with sunflower until the 10-leaf and anthesis stages of sunflower growth, respectively. When hemp sesbania was allowed to compete with sunflower for the entire growing season, yield was reduced by as much as 35%. Reducing row width from 91 cm to 61 cm did not improve sunflower's ability to compete with hemp sesbania. Thus, hemp sesbania is quite competitive with sunflower and should be controlled during early vegetative growth in order to minimize yield loss.     

Growth and Yield Performance of Some Cotton Cultivars in Xinjiang,China, An Arid Area with Short Growing Period

Eleven cotton (Gossypium hirsutum L.) cultivars were evaluated for their growth and yield performance in Shihezi, Xinjiang, China, an area in Central Asia with short growing period in 1999 and 2000. In each cultivar the number of bolls per plant was low and the number of bolls per unit area was high. Each cultivar showed rather high seed and lint yields. The highest lint yield was Xinluzao 10 in both years with 1761 and 1809 kg ha^?1. High yield ability of the cultivars in this study was attributed to large number of bolls per unit area with high lint percentage. Seed and lint yields had significant positive correlations with mean net assimilation rate, ratio of reproductive to vegetative organs and mean boll weight at earlier stages of boll growth, suggesting that early boll formation and successive partitioning of dry matter into bolls were important factors for boll growth in this study area.     

Effects of Removal of Redundant Buds and Topping of Fruiting Branches on Source-Sink Activity,Yield, and Fiber Quality of Cotton

[Objective] Removal of redundant buds and decapitation of fruiting branches are important pruning measures for cotton production. The effects of the two procedures on source–sink activity, yield, and fiber quality were studied to provide a scientific basis for a simplified pruning method. [Method] A field trial was carried out in bottomland of the Yellow River valley, Zhengzhou, Henan Province in 2014–2015 using cotton ‘Lumianyan 28’. Treatments consisted of removal of redundant buds, decapitation of fruiting branches, and removal of redundant buds and decapitation of fruiting branches in combination (RDR treatments). Redundant buds and tops of fruiting branches were retained in the control (CK). The source–sink size and activity, yield traits, fiber quality, and economic return were recorded. [Result] The RDR treatments increased the leaf area index and total dry matter accumulation, and increased the sink-source ratio at advanced growth stages compared with CK. In the middle growth period, the RDR treatments increased indoleacetic acid (IAA) content and superoxide dismutase (SOD) activity, and decreased abscisic acid (ABA) content in the leaf. Moreover, the RDR treatments increased IAA content and SOD activity, and decreased ABA content in seeds of pre-summer bolls and summer bolls, whereas the IAA and ABA contents and SOD activity in fibers showed the opposite trend to that of seeds. The lint yield following removal of redundant buds, decapitation of fruiting branches, and combined removal of redundant buds and decapitation of fruiting branches was increased by 4.43%, 5.17%, and 9.31%, respectively, but no significant difference was observed among these treatments. Decapitation of fruiting branches had amore marked effect on yield than removal of redundant buds, and these two treatments applied in combination had a cumulative effect on yield. The RDR treatments had no significant effect on fiber quality. Decapitation of fruiting branches increased economic return, but removal of redundant buds reduced economic return, and the effect on economic return of removal of redundant buds and decapitation of fruiting branches in combination was inconsistent. [Conclusion] The RDR treatments generally improved the source–sink relationship, enhanced source and sink activity, and increased cotton yield. However, the increase in yield and economic benefits were less marked. We recommend simplified pruning techniques without removal of redundant buds and decapitation of fruiting branches for large-scale cultivation of cotton.     

棉花对初蕾期物理伤害的调节补偿效应

黄河流域棉区棉花在蕾期常遭遇冰雹所致的物理伤害,但棉花具有一定的调节补偿能力。明确棉花对不同程度物理伤害的补偿效应,对灾后棉田管理具有指导意义。以山东主栽棉花品种K836为材料,于2014—2015年棉花现蕾后第5天在山东省临清市设置去顶去叶(RTL)、去顶留1叶(RT+1LM)、去顶留叶(RT+ALM)、留顶去叶(TM+RL)、留顶留1叶(TM+1LM)以及未损伤的正常植株(CK) 6个处理,研究不同程度损伤对棉花生长发育、叶面积动态、净光合速率、生物量、棉柴比、产量及产量构成的影响。结果表明,对于棉花单株干物质量, TM+1LM处理在15 DAT和30DAT(物理伤害后天数)分别比CK降低59.0%和12.1%,但在45DAT和60DAT与CK无差异;其余伤害处理在15～60 DAT均不同程度降低。叶面积指数变化动态与干物质积累趋势一致。处理45 DAT内, RTL、RT+1LM、RT+ALM和TM+RL的净光合速率均低于对照,且高峰值出现时间推迟, TM+1LM的净光合速率变化趋势及高峰值出现时间与对照一致。TM+RL生物产量较CK降低18.2%,而RTL、RT+1LM、RT+ALM和TM+1LM的生物产量与CK相当; RTL、RT+1LM、RT+ALM和TM+RL的棉柴比分别比CK降低52.6%、47.3%、36.8%和23.7%,而TM+1LM的棉柴比与CK无明显差异。RTL、RT+1LM、RT+ALM和TM+RL单位面积铃数分别减少19.0%、7.2%、9.9%和15.6%,单铃重分别降低23.2%、8.9%、8.9%和19.6%,籽棉产量分别降低36.3%、17.5%、15.5%和31.9%,而TM+1LM的铃数和单铃重没有显著降低,籽棉产量与CK相当。据此,把蕾期物理损伤分为轻度损伤(TM+1LM)、中度损伤(RT+1LM、RT+ALM)和重度损伤(RTL、TM+RL),其减产幅度分别在5%以内、15%左右和30%以上。对于轻度和中度损伤棉田,宜加强水肥管理促进棉花补偿性生长,减少产量损失;对于重度损伤棉田,可以考虑改种其他短季作物。     

Influence of Water Stress on Grain Yield and Vegetative Growth of Two Cultivars of Bean (Phaseolus vulgaris L.)

Lack of water during vegetative and/or reproductive growth stages is one of the most limiting factors for bean growth. The purpose of this study was to evaluate the effects of water stress applied during two phenological stages (flowering and pod filling) on growth, yield and yield components. Two genotypes of bean ( Phaseolus vulgaris L.) were used in this study, cv. Carioca, an indeterminate Brazilian landrace, and cv. Prince, a determinate cultivar grown in Europe. Carioca appears to be generally stress-tolerant while Prince is intolerant. Plants were grown in large plastic pots covered with a black plastic sheet to protect the soil from rain and evaporation. The water stress treatments were: control (well-watered plants), WSFS (water stress during flowering stage) and WSPFS (water stress during pod-filling stage). Water stress reduced yield and yield components at both flowering and pod-filling stages. The parameters affected were seed weight, number of seeds per plant and number of pods per plant. Number of seeds per pod and seed weight were not affected. No effects of water stress were detected on harvest index. Time to maturity was slightly prolonged, especially for WSFS. Water stress at both stages resulted in lower accumulated water loss compared to the control plants. Water stress during both phenological stages reduced other growth parameters, the number of trifoliate leaves, stem height, number of main branches and number of nodes on the main stem.     

红叶棉花的产量杂种优势研究初探

利用综合性状表现较好的3个红叶材料作父本,与15个绿叶转基因棉花新品种(系)组配19个红叶杂交组合,研究了具有红叶标记性状棉花的产量杂种优势表现,结果表明:19个红叶杂交组合子棉产量具有明显的杂种优势,皮棉产量的具有正向中亲优势、正向超亲优势和负向竞争优势,衣分和单铃重具有正向的中亲优势,单株铃数表现正向中亲、超亲和竞争优势,筛选出产量竞争优势在5%以上、综合性状较好的优势组合4个。     

Effects of Seeding Date and Topping Date on Yield and Fiber Quality of Short-Season Cotton Field-Seeded after Barley(Rape)/Wheat Harvest

[Objective] The aim of this study was to evaluate the effects of seeding date and topping date on yield, yield characteristics and fiber quality of short-season cotton (CCRI 50) field-seeded after barley(rape)/wheat harvest. [Method] A split-plot design with three replicates was used for the study in Nanjing, Jiangsu province of China in 2014-2015. The main plots comprised two seeding dates (S₁: 25th May and S₂: 10th June), while topping dates (T₁: 30th July, T₂: 7th August and T₃: 15th August) constituted the subplots. [Result] The lint yield, the ratio of yield before frost, boll number, boll weight and lint percent of S₂ were lower than those of S₁. The number of fruit branches and fruit nodes of S₂ were less than those of S₁ while it was the opposite for the boll setting ratio. The lint yield and the ratio of yield before frost decreased with the delay of topping date. The number of fruit branches and fruit nodes, the ratio of them increased with the delay of topping date while the boll setting ratio decreased. The interaction of sowing date × topping date showed that the treatment of S₁T₁ achieved higher value in lint yield and the ratio of yield before frost. The higher number of fruit branches and fruit nodes were found at the treatment of S₁T₁, S₁T₂ and S1T3 and higher boll setting ratio were found at the treatment of S₂T₁ and S₁T₁. Correlation analysis showed that the lint yield positively and significantly correlated with the number of fruit branches and fruit nodes and boll number, but did not significantly correlate withboll setting ratio and the ratio of fruit branches number to nodes number. In addition, the boll distribution ratios of middle and low fruit branches of S₂ were more than those of S₁ while it was the opposite for that of up fruit branches. The boll distribution ratios of middle and low fruit branches decreased with the delay of topping date while it was the opposite for that of up-fruit branches. The treatment of S₁T₁ could be better to improve fiber length and fiber strength of different fruit branches and the micronaire value of middle fruit branches. [Conclusion] The treatment of S₁T₁ is conducive to high yield and fiber quality of short-season cotton field-seeded after barley(rape)/wheat harvest in lower reaches of the Yangtze River.     

干旱胁迫对彩色棉花农艺、品质性状及水分利用效率的影响

为了探索干旱胁迫对彩色棉花主要性状的影响及其水分利用机理,选用7个不同色彩的棉花品种(系),在常规灌溉、胁迫灌溉和生育期不灌溉3种环境条件下,调查其农艺性状、品质性状、水分利用效率(WUE)及产量。结果表明,干旱胁迫下不同色彩棉花品种的单株成铃数、单铃重、株高、花铃期叶片数、有效果枝数、收获指数、果节数、籽指、茎粗和果茎节间长度减少,衣分增加;灌水量减少一半,参试棉花品种的产量均降低,不灌溉处理的籽棉产量与常规灌溉间差异显著(P<0.05);籽棉产量的降低幅度品种间存在较大差异(P<0.05),棕色棉的减产幅度高于绿色棉。常规灌溉处理下,白色棉花水分利用效率高于棕色棉花和绿色棉花,而后二者差异不显著;干旱胁迫下,棕色棉花的水分利用效率高于绿色棉花。与水分利用效率相关的主要农艺性状、品质指标是：叶片数、单株成铃数、有效果枝数、果节数、株高、收获指数、单铃重、主茎节间长度、茎粗、籽指、衣分。     

Analysis of the Main Decision Characters of Cotton Yield in Heilonggang Cotton Region of the Yellow River Basin

[Objective] In order to improve the efficiency of variety selection and reduce the cost of experiment, it was necessary to select the multi-objective characters comprehensively and make clear the effect of each objective character on the yield of seed cotton. [Method] Through the statistical analysis of 8 years, 607 breeding materials (339 conventional varieties and 268 hybrids) of Guoxin Rural Technical Service Association in Hejian City, Hebei Province, the effects of plant type, yield, maturity and fiber quality on the yield of seed cotton were comprehensively evaluated. [Result] Correlation analysis, regression analysis and general analysis showed that boll weight, lint percentage, first fruiting branches node, percentage of seed-cotton before frost and growth period had significant effects on seed cotton yield in the Heilonggang Cotton Region of the Yellow River Basin. The correlation coefficient between percentage of seed-cotton before frost and seed cotton yield were the highest (r＝0.320 97), and the boll weight decision coefficient was the largest (R²＝0.30), which were the main traits affecting the seed cotton yield. Plant height had the largest direct effect on seed cotton yield, but the total effect was the smallest after indirect effects of other variables (r_2y＝－0.04). Both regression and general analysis showed that neither fiber length (upper half mean length) nor micronaire had significant effects on seed cotton yield. [Conclusion] During the breeding of new cotton lines in the Heilonggang Cotton Region of the Yellow River Basin, boll weight and lint percentage can be used as important agronomic characters for breeders to improve. Shortening the growth period and increasing the percentage of seed-cotton before frost can increase yield. Plant height and first fruiting branches node affect seed cotton yield through interaction with other traits. Neither the fiber length nor the micronaire value have a significant effect on the seed cotton yield, which can be increased simultaneously with the yield during the breeding process.     

棉花产量结构模型的研究

经过1987和1988两年在河南安阳和江苏扬州二个点的田间试验研究,分别建立了棉花纤维产量构成因素公顷铃数、单铃重和衣分对产量影响的数学模型,以及播期、追施氮肥、密度、喷缩节安、去早蕾、留果枝数等栽培措施对产量构成各因素影响的数学模型。分析指出,产量构成因素的重要地位随地区不同而变化,主要栽培措施是依据一定地区和一定年份而言的。在安阳地区,铃重是影响产量最重要的因素,而去早蕾、密度和追施氮肥又是影响铃重的主要栽培措施,这三项措施的重要性顺序随着年份不同而不一样;在扬州地区,公顷铃数是贡献于产量的最重要因素,而密度又是影响公顷铃数的关键栽培措施,留果枝数和追施氮肥的地位则因年份不同而分别居第二、第三位。这为棉花生产因地因时制宜,抓主要矛盾提供了科学依据。     

施氮量对科棉3号干物质积累及分配、产量和纤维品质的效应

 研究了N素积累对高品质棉（科棉3号）干物质积累及分配、产量和纤维品质的效应,结果表明,提高盛铃期蕾铃干物重是高产的关键,盛蕾至盛花期营养器官和盛花至盛铃期各器官N素积累与盛铃期棉花蕾铃干物重呈显著正相关。伏桃产量随盛花期棉花各器官N素积累增加而显著提高,伏桃产量和早秋桃产量分别随盛铃期叶片和茎枝N素积累增加而提高,伏桃、早秋桃和晚秋桃产量随盛铃期蕾铃N素积累增加而提高。施N量对棉花纤维品质的影响主要是影响烂铃率和纤维N代谢。综合来看,施N量过高,主要是导致烂铃率大幅度提高,对纤维长度、强度和麦克隆值等影响都大,而在适宜施N量以内,施N量增加,棉纤维强度和麦克隆值表现为降低的趋势,而对棉纤维长度影响不大。     

翻耕深度对膜下滴灌棉花农艺性状及产量的影响研究

为了探明翻耕深度对新疆膜下滴灌棉花生长的影响,通过设置3个翻耕深度（10 cm、30 cm和50 cm ）处理,研究不同翻耕深度对棉花农艺性状及产量构成的影响。结果表明,翻耕深度对棉花生育进程影响显著,翻耕30 cm和50 cm分别比翻耕10 cm全生育期延长20天和25天。同时翻耕深度增加使棉花株高、果枝数、主茎叶片数和单株铃数均显著增加,LAI增大。翻耕深度增加,棉花中、下部结铃比例减小,上部铃比例显著增加,同时皮棉产量显著增加,翻耕30 cm比10 cm增加52.9%,翻耕50 cm比30 cm增加9.2%。而收获株数和单株结铃数增加是皮棉产量提高的主要原因。综合分析认为,深翻耕有利于连作棉田棉花生长及产量水平提高。     

整枝方式与种植密度对蒜套棉产量和品质的效应

以棉花抗虫杂交种鲁棉研15号(F1)为材料,在鲁西南3个不同的地点,研究了整枝方式(去叶枝、留叶枝)与种植密度(2.7、3.3、3.9、4.5万株·hm-2)对棉花产量和纤维品质的影响。结果表明,整枝方式和种植密度对棉花纤维品质的影响不显著,但对棉花产量有显著的互作效应,3.3万株·hm-2×留叶枝、2.7万株·hm-2×留叶枝和3.3万株·hm-2×去叶枝的组合比传统栽培(2.7万株·hm-2×去叶枝)分别增产20.4%、9.2%和10%,也显著高于其他处理组合;生物产量分别提高了13.7%、27.8%和11.6%,而经济系数只降低了5.3%、11.5%和4.5%。在维持较高经济系数和铃重的基础上增加生物产量和铃数是该3个处理组合显著增产的原因,适当提高密度并配合简化整枝是实现蒜套棉高产高效的重要技术途径。