不同种植方式对大跨度外覆盖大棚番茄群体微环境及植株生长与产量和品质的影响

以番茄品种罗拉为试材,设置5个处理,分别为:CK,定植密度33 300株·hm~(-2),留6穗果;T1,49 500株·hm~(-2),留4穗果;T2,66 000株·hm~(-2),留3穗果;T3,49 500株·hm~(-2),单株留2穗果与留6穗果相间;T4,66 000株·hm~(~(-2)),单株留2穗果与留4穗果相间,研究不同种植密度和留果方式对外保温覆盖大棚内番茄植株生长、产量、品质、群体微环境的影响。结果表明:T2和T1处理生育期平均温度、温度适宜度较高;T1和T3处理摘心前的叶片SPAD值显著高于对照;T1、T2处理的前期产量和总产量均显著高于对照;VC、可滴定酸、可溶性糖、番茄红素等果实品质以T1处理最优。综合产量、品质以及大棚内的温湿度和光照适宜度,T1处理种植风险较小,是外保温覆盖大棚中较为合适的种植方式。     

浅析完善中国森林生态效益补偿制度

随着地球人口的增加和人类活动的加剧,保护森林资源已经提上了各国的议事日程。而对于我国这样的一个贫林国家,森林资源的保护问题与森林生态效益的补偿就显得愈加迫切与重要。文章针对我国现有的森林生态效益补偿制度的沿革、存在的问题进行了分析,并提出我国森林生态效益补偿制度需进一步完善或创新。     

油松林内横山叠梗天然更新试验

为防止雨水将油松落果和种子冲击至山下腹或沟谷,影响自然撒种更新数量,进行了横山叠梗的留存种子方法试验,结果表明横山叠梗可大量提高油松的更新数量,试验区平均更新量为523.6万株hm^-2,是对照区更新量的5.29倍.油松林内横山叠梗天然更新效果显著.     

Square‐mesh codend length and selectivity in southeastern Australian stow nets

Abstract The relationship between the amount of square mesh in codends and selectivity was investigated for an Australian penaeid stow‐net fishery. Three lengths (3, 2 and 1 m) of square‐mesh codend made from 27‐mm mesh hung on the bar were alternately tested with a conventional 34‐mm diamond‐mesh design during two covered‐codend experiments. Compared with the conventional codend, the square‐mesh configurations incrementally selected school prawns, Metapenaeus macleayi (Haswell) across narrower selection ranges (SR) and mostly at greater sizes at 50% retention (L₅₀), while retaining fewer fish. Irrespective of the mesh configuration or square‐mesh codend length, there were significant differences between experiments (attributed to water flow) and impacts of catch weight on the selectivity of school prawns. Both variables had a negative relationship with L₅₀, while water flow similarly affected SR. This study reaffirms the utility of square‐mesh codends as a key input control for managing the selectivity of penaeid‐catching gears.     

鲜活农产品在连云港市的物流与营销

指出了人们对农产品的消费观念发生了深刻的变化，从消费者对农产品的需求及消费者购买行为两方面分析了连云港市的市场环境，并对鲜活农产品在连云港市的物流与营销进行了探讨。     

农村公共产品供给与减轻农民负担

农民负担实际上是与农民有关的公共产品成本的分摊，而这种分摊存在着体制缺陷，这种缺陷导致了农民的生产效益低下，农民负担逐步加重。要改变这种现状就必须对农村公共产品供给体制进行改革和完善，以期从根本上减轻农民负担。     

健全农村公共物品供给中农民需求表达机制的探讨

从农民需求表达与农村公共物品供给的关系入手,揭示出农民需求表达与公共物品最优供给的内在联系,说明了建立健全农民需求表达机制在促进农村公共物品供给中起着举足轻重的作用。从农民、农民组织和政府三个层面剖析了当前我国农民需求表达机制中存在的问题并提出健全和完善的对策建议。     

Effect of the Substrates on the Production of Engrafted Vine Cuttings in Heated Greenhouses

This article highlights the results of a long-term research project on the production of grape stalks engrafted by the desk method. The integrated impact of rootstock varieties, modes of stratification, and different substrates on vegetating vine cuttings, raised in heated greenhouses, and the capacity of their acclimatization after planting was studied. The results of the research show that rootstock variety and modes of stratification influence the output of engrafted vegetating cuttings of vines grown in pots using various substrates. In particular, the engrafted cuttings of variety Rkatsiteli produced on two rootstocks, 5 BB and 101-14, passed stratification (a) in sawdust with local electroheating, (b) on the water with its periodic change, and (c) in the layer of perlite. After preplanting preparations they were planted in pots with six different substrates: (1) soil (control); (2) perlite; (3) sawdust; (4) rice husk + soil + sand (1:1:1); (5) peat + soil + sand (1:1:1); and (6) mold + soil + sand (1:1:1). The cuttings were grown with a covered root system in a heated greenhouse for 35–40 days. Forty-day-old vegetating cuttings, after hardening, were planted into the open ground. Specialties were established during the root and shoot formation on vegetating nursery plant grafts during the rooting period. Optimal substrates for growing engrafted cuttings with a covered root system in heated greenhouses for each rootstock and stratification mode were determined.     

高校植物组织培养实验室管理方法探讨

高校组培室中危险物品种类较多,应加强实验室管理人员的基本技能训练,提高其工作积极性,并对危险品进行合理保管,督促学生掌握好危险设备的正确操作方法,从而减少实验室事故的发生.规范实验室低值易耗品购置,普及管理软件的应用,为高校实验室科学化管理提供有力保障.     

地膜覆盖栽培甜菜的适宜揭膜期

3 年地膜覆盖栽培甜菜不同揭膜期试验结果表明:以5 月30 日和5 月20 日揭膜为适期,根产量与对照比可分别增产12 .3% 、10 .8% , 含糖率分别增糖0 .76 度、1.0 度; 两揭膜期甜菜地上部长势均显著好于其它处理; 不同处理5 ～10cm 地温调查结果看出, 从5 月20 日以后地膜覆盖逐渐失去增温效应。据焉耆的气候、土壤条件,当地地膜覆盖甜菜的适宜揭膜期为5 月20 日～5 月30 日。