为推进香蕉生产机械化的农机与农艺结合,按照耕、种、管、收、运等关键作业过程的要求,设计和实践了配套简易机械化栽培的香蕉宽窄行种植模式,有效实现了香蕉园从整地、种植、田间管理、收获、运输等过程的机械化作业,有效利用土地和空间,提高通风透光性和光能利用率,促进植株生长发育,减少劳力和成本,提高生产效率、产量和品质,具有较高的推广应用价值.

为了评价不同香蕉品种在广西的表现,对广西崇左市龙州县10月秋植的6个香蕉品种(桂蕉6号、中蕉3号、中蕉4号、中蕉6号、巴西蕉、南天黄)的生长发育、结果性状和产量进行了比较,旨在为广西香蕉生产的品种结构调整提供理论依据.试验结果表明:在整个生长发育阶段的同一时期,生长最旺的是中蕉3号,最弱的是南天黄,中等的是桂蕉6号、中蕉4号、中蕉6号和巴西蕉.生育期最长的是桂蕉6号和巴西蕉,比生育期最短的中蕉3号和中蕉4号多17.8 d,南天黄和中蕉4号居中.产量最高的是桂蕉6号、中蕉3号、中蕉4号和中蕉6号,但4个品种间产量没有显著差异,其次是巴西蕉,最低是南天黄.果实综合性状较好的是中蕉4号、桂蕉6号、中蕉3号和中蕉6号,南天黄和巴西蕉较差.从综合表现看,中蕉3号、桂蕉6号、中蕉4号和中蕉6号表现较好,适合在广西种植并获得较高产量,南天黄和巴西蕉表现较差.香蕉不同品种的假茎高度、假茎围和叶片数的月增长量与月积温均呈显著或极显著相关关系,在一定温度范围内,高温促进香蕉植株的生长,低温则抑制香蕉植株的生长.

根据母本龙特甫A育性易受温光条件影响等特性及广西博白县的气候特点,总结了特优679高产制种技术.

【目的】于火龙果成熟季节对火龙果的裂果情况进行调查,分析裂果原因,为生产上制定栽培管理技术措施提供参考依据。【方法】以平果坤汇特生态农业公司火龙果果园和广西农业科学院里建科研基地火龙果种质圃为调查点,以红肉1号、红肉2号、紫龙、美龙2号、华农、红绣球、红肉优株4号、红肉优株7号等8个火龙果品种为试验材料,于6~11月在每批火龙果果实成熟后1~2 d开展裂果情况调查,观察不同品种裂果数量、裂果部位及裂果程度。【结果】果脐收口较宽且浅的品种易从果脐处呈纵向裂开,且果形为圆球形或短椭圆形的品种比椭圆形的品种裂果严重,裂果率最高达19.4%;果皮薄且脆、弹性差、质地柔软的品种易从果实腹部果皮裂开,裂果率最高为6.3%。火龙果果实生长成熟期间久旱遇雨或长时间下雨均易造成裂果,土壤黏重的果园较黄壤土果园裂果严重,在果实生长成熟期间偏施化肥及感染病虫害的果实也易发生裂果。【结论】火龙果裂果与其品种、果实成熟季节及栽培管理有关,生产上应选择抗裂果品种推广种植,加强果园管理,改良土壤,均衡土壤水分供应,实行果实套袋等措施减轻裂果发生。

开展火龙果种质资源收集和保存并建立种质资源圃,对其特性进行观察和评价,为火龙果种质资源的进一步研究和利用提供科学依据.目前共收集到火龙果仙人掌科量天尺属(Hylocereus undatus)和蛇鞭柱属(Seleniereu)植物152份,以田间种植保存方式保存在火龙果种质圃;通过对32份红肉火龙果种质自然开花结果特性调查结果表明,自然开花座果率达80％以上的占56.2％,单果重350 g以上占31.3％,自然开花座果率高的品种平均单果也重;果实性状分析结果表明,成熟果实果肉中心可溶性固形物含量18.0％以上的占59.4％,最高达20.5％,可溶性固形物含量在种质资源中有明显差异,根据对火龙果的风味和口感测试,发现果肉可溶性固形物高的种质其风味为优.

In this article, we will give several conditions under which the following planar linear discrete Hamiltonian system with perturbations{Delta x(n) = [alpha(n) + alpha(1)(n)]x(n + 1) + [beta(n) + beta(0)(n)] y(n) + f(1)(n, x(n), y(n)),Delta y(n) = -[gamma(n) + gamma(0)(n)]x(n + 1) - [alpha(n) + alpha(2)(n)] y(n) + f(2)(n, x(n), y(n))has the same stability as the corresponding linear systemDelta x(n) = alpha(n)x(n + 1) + beta(n)y(n),Delta y(n) = -gamma(n)x(n + 1) - alpha(n) y(n).Moreover, these conditions are shown to be necessary and sharp by examples.

The diversity and genetic relationship among and within thirty-six varieties of longan and one Dimocarpus confinis from China,Vietnam and Thailand were analyzed using SCoT(Start Codon Targeted) and ISSR(Inter Simple Sequence Repeat) markers.The results showed 127 strips were amplified by 12 SCoT primers while 117 strips by 15 ISSR primers.The average strips amplified by SCoT and ISSR primers were 10.58 and 7.8,respectively.The genetic relationships were analyzed using unweighted pair-group method of arithmetic average cluster analysis(UPGMA)and the genetic Jaccard similarity coefficients were calculated.The cluster analysis results showed that the thirty-seven materials could be clustered into 6 groups at the similarity coefficient level of 0.672 and 0.685.Comparison and mixture analysis of the two molecular markers demonstrated that both SCoT and ISSR were efficient approaches for genetic diversity analysis of longan germplasm.These results would provide theoretical basis for longan germplasm storage and utilization in future.

In this paper, we obtain some sufficient conditions for the oscillation of all solutions of the second order half-linear difference equationDelta(r(n)vertical bar Delta x(n)vertical bar(alpha-2) Delta x(n)) + p(n)vertical bar x(n+1)vertical bar(alpha-2)x(n+1) = 0, n = 0,1,2, ....,where Delta x(n) = x(n+1) - x(n) is the forward difference operator, {r(n)} is a sequence of positive real numbers, {p(n)} is a sequence of nonnegative real numbers and alpha > 1. One open problem in Remark 3 of Rehak (2000) [1] is solved. (C) 2011 Elsevier Ltd. All rights reserved.

Consider the existence of homoclinic solutions for the following non-autonomous p-Laplacian system d/(dt)(|u·(t)|p-2u·(t))-l(t)|u(t)|p-2u(t)+▽W(t,u(t))=0.By making use of the least action principe of critical-point theory,we obtain nontrivial homoclinic solutions of the system.This result generalize and improve some existing results in the literature.

In this paper, by using elementary analysis, we establish several new Lyapunov type inequalities for the following nonlinear dynamic system on an arbitrary time scale T{xΔ(t)=α(t)x(σ(t))+β(t)|y(t)|p−2y(t),yΔ(t)=−γ(t)|x(σ(t))|q−2x(σ(t))−α(t)y(t), when the end-points are not necessarily usual zeros, but rather, generalized zeros, which generalize and improve all related existing ones including the continuous and discrete cases.

为探讨早春极端低温对龙眼成花的影响及芒果和荔枝花穗冷害发生时应对措施的效果,在2008年早春低温冷害时,通过抹除芒果和荔枝的冷害顶生花穗,研究该应对措施对促进腋芽再分化花芽并抽生花序的效果,并在低温冷害后,对不同龙眼品种的成花情况进行调查.结果表明:抹除荔枝冷害顶生花穗后能显著促进黑叶、钦州红荔、糯米糍、立夏红腋芽再生花序,平均单株花穗数分别为139、62.5、28和29穗,分别比对照的高119、22.5、25和26穗;而妃子笑、三月红、桂味和禾荔的处理树和对照树之间差异不明显.抹除芒果冷害顶生花穗后,台农1号、贵妃、桂热82号、红象牙和金穗芒的平均单株成花数分别为92、18、131、20.5和18穗,明显高于对照;而凯特芒、桂热120、吉尔、紫花芒和金穗芒处理树和对照树之间差异不显著.龙眼低温冷害后成花较好的有桂明、储良、石硖、小广眼、大乌圆和大广眼,平均单株花穗数分别为88、67、52.7、52、51和50穗;其次是桂香、乌龙岭、东壁、立冬本和早白露,平均单株花穗数分别为39、26、25、23.5和21.5穗.

We study the existence and multiplicity of periodic solutions of the following second-order Hamiltonian system u ̈ ( t ) + ∇ [ − K ( t , u ( t ) ) + W ( t , u ( t ) ) ] = 0 . The existence of a nontrivial periodic solution is obtained when ∇ W is asymptotically linear at infinity, and the existence of infinitely many periodic solutions is also obtained when ∇ W is superlinear.

The present experiment was conducted to analyze the effect of no-tillage and straw covering for sweet potato on the soil total organic carbon content,active organic carbon,carbon pool and the quantity of microorganism using conventional cultivation as the control.The results indicated that the no-tillage cultivation with straw covering enhanced the total organic carbon and active organic carbon contents and the carbon pool indices in 0-10cm depth of soil layer,while it had no significant effects on 10-20 cm depth of soil layer.It was found that the quantity of bacteria,fungi and actinomyces in 0-10 and 10-20 cm depth of soil layer was higher than that of conventional cultivation,which demonstrated that no-tillage with straw covering could increase the quantity of soil microorganism.Therefore,applying no-tillage with straw covering for a long time would be beneficial for enhancing the soil fertility,and improves environment for soil microorganisms.

本研究利用ISSR技术对37份龙眼种质资源进行遗传多样性检测。研究结果表明,从100条ISSR引物中筛选出7条重复性好,条带清晰的引物对37份龙眼品种基因组DNA进行扩增,共扩增出54条带,其中43条具有多态性,比率为79.6%。不同龙眼品种间遗传相似系数变幅为0.69～0.97,平均达0.83,说明ISSR标记能够揭示材料间较高的遗传多样性。UPGMA聚类结果表明,ISSR标记能将37份龙眼品种完全区分开,并能将来源于中国、越南和泰国的37份龙眼品种分别聚类到中国、越南和泰国三大品种群,说明龙眼品种资源的亲缘关系与地理因素有关,三个国家的龙眼品种之间存在较大的遗传差异。本研究结果将为为龙眼品种资源的研究利用提供参考。

Students of agronomy begin their speciality practice and scientific research training under guiding of teacher from the first semester at the field innovation opening laboratory.Students can publish articles and gain patent through scientific test under item of tutor,contributing to new countryside of socialisim during the students'course.

In the experiment,winter potato variety Favourite was used as material and the effects of three different mulch on the yield and quality of potato in rice paddy was studied.The results showed that the emergence rate of potato under traditional cultivation was the highest,the yield and the commodity rate of potato under no-tillage and covering rice straw which thickness was 4 cm before covering black plastic was the highest.Moreover,all mulch treatments had obvious effects on the total sugar,protein content,reducing sugar and starch content.In all treatments,sugar and protein contents in potato under traditional cultivation were higher,while the reducing sugar and starch contents under no-tillage with straw and corn straw were higher.

根据考察和学术交流收集到的资料,综述了越南柑桔生产概况、不同生态区柑橙生产情况、越南柑桔种质资源和商业化栽培的主栽柑桔品种特性,对促进中越柑桔学术交流具有重要的意义。

以"桂薯131"为试验材料,进行红薯3种不同栽培模式比较试验,探讨不同耕作方式对红薯生理特性的影响.结果表明,在整个生育期,免耕稻草覆盖栽培红薯的根系活力均比传统栽培的高,在生长中后期,免耕稻草覆盖栽培的红薯叶片叶绿素含量、游离脯氨酸含量、过氧化氢酶活性、超氧化物歧化酶活性均显著高于传统栽培;两种免耕栽培处理方式比较,以先在畦面覆盖3cm厚稻草,摆放薯苗,然后覆盖8cm,厚稻草处理红薯的各项生理指标最高.

Applied different fertilizers to Vitis vinifera cv.Kyoho at its coloration stage to study the effects on the maturity,TSS,quality and flavor of grape fruits.The results showed that fruit maturity of kyoho grape which applied with compound fertilizer,compound fertilizer plus K2SO4 and peanut cake-meal were 4d,9d and 9d earlier,and the pulp TSS were 1%,1.6% and 2.3% higher than the control respectively;and which fertilized with urea was 2d later and the pulp TSS was 0.6% lower than the control.