Outdoor winter storage of container stock on raised pallets—effects on root zone temperatures and seedling growth

Containerized seedlings of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) were overwintered on the ground and above ground on pallets. Soil temperatures in elevated containers were lower and showed greater fluctuation than containers on the ground. The lowest temperatures (‐15 to ‐16°C) were observed in containers stored on pallets with little or no snow cover during the winter. Temperatures in the edge rows of containers were lower than interior bed soil temperatures. Lower temperatures were also observed in the top than in the bottom of the container. The storage on pallets resulted in reduced shoot and root growth. Although insulation preventing air movements beneath the container units improved soil temperature conditions and subsequent seedling growth, the best result was obtained when seedlings were stored directly on the ground surface.     

赤松纯林胸径结构对枯梢病发生的效应

目的 探究赤松纯林胸径结构对枯梢病发生效应,为合理采取森林经营措施调整林分胸径结构,防控赤松枯梢病的流行提供理论支持和技术支撑。 方法 以昆嵛山赤松纯林为研究对象,设置50块赤松纯林临时样地进行赤松胸径及枯梢病病情调查,应用Weibull分布拟合位置、尺度和形状参数并进行$ {x}^{2} $检验,然后将3参数和赤松平均胸径,感病赤松平均胸径,未感病赤松平均胸径,最大病级赤松平均胸径,最小病级赤松平均胸径表征为赤松胸径特征指标,分别与枯梢病病情指数进行Spearman秩相关性分析。 结果 各赤松纯林临时样地胸径结构均符合Weibull分布,其中胸径分布中心在9.66 ~16.25 cm,90.00%的样地胸径结构表现为正偏山状分布。赤松枯梢病病情指数与未感病赤松平均胸径、最大病级赤松平均胸径和最小病级赤松平均胸径呈负相关,但检验结果为不显著;与尺度参数、赤松平均胸径和感病赤松平均胸径呈显著负相关（p<0.05）,与形状参数呈极显著负相关（p<0.01）;与位置参数呈间接显著负相关。 结论 Weibull分布能够较好地拟合赤松纯林胸径结构。赤松纯林枯梢病病情指数与胸径结构分布中心、胸径结构分布曲线形状、赤松平均胸径和感病赤松平均胸径结构指标存在显著或极显著负相关,与所测赤松最小胸径存在间接显著负相关,可采取抚育间伐等森林经营措施增加林内优势木比重,降低赤松胸径分化程度,减少感病小胸径赤松,达到赤松枯梢病生态调控的目的。     

A viability study of Fallopia japonica stem tissue

Vegetative regeneration of intact and split nodes of Fallopia japonica (Houtt.) Ronse Decraene was the focus of this greenhouse experiment. Stem material, collected in May, July and September 1997, was cut into 40-mm-long sections and incubated on the surface of moist compost in a greenhouse. All samples showed some regrowth of buds and new shoots from both intact and split nodes in any season. A maximum number of 0.25 buds per intact node was recorded after 6 days in a spring experiment. The vegetative regrowth of shoots generally appeared after 1 week and increased over time with a maximum mean height of 77 mm after 27 days and a maximum number of 0.39 shoots per intact node after 13 days. Adventitious roots developed from both intact and split nodes during both summer and autumn experiments. From this study, a maximum of 90 stem tissue propagules per square metre of F. japonica stand has been estimated. If the plant is cut as part of a control programme, these propagules can produce shoots with growth rates of up to 2.9 mm per day with a good chance of the development of adventitious roots. This considerable potential for vegetative regeneration of stem tissue shows a clear need for guidelines on the safe management and disposal of F. japonica plant material.     

草地螟寄生蝇寄生规律及控害作用研究

田间调查和室内饲养观察表明,康保县草地螟的寄生蝇主要有伞裙追寄蝇、双斑截尾寄蝇等5种。草地螟寄生蝇一般只寄生幼虫,未见寄生其他虫态。寄生率随草地螟幼虫密度增大、虫龄增长而迅速升高。多年发生资料分析,寄生蝇寄生率高的年份,下年草地螟的发生为害程度明显减轻。     

中国南方竹区4种竹笋夜蛾的形态比较研究

竹笋夜蛾是我国重要的一类竹子笋期害虫,种类多,形态相似,难以区分,为更为准确地识别主要竹笋夜蛾的种类,本研究通过野外取样和室内饲养,对竹笋基夜蛾Kumasia kumaso、竹笋禾夜蛾Oligia vulgaris、笋连秀夜蛾Apamea repetita conjuncta及竹笋秀夜蛾Apamea apameoides 4种竹笋夜蛾卵、幼虫趾钩、臀棘及成虫翅脉和生殖器形态进行了观察和比较。结果表明,竹笋基夜蛾在卵形态、幼虫体色和雌雄生殖器形态上与其他3种竹笋夜蛾形态差异明显,其余3种夜蛾幼虫体表背线和亚背线形态有差异,趾钩、臀棘、翅脉和雌、雄外生殖器形态差异不显著。本研究明确了我国南方竹区4种竹笋夜蛾的形态差异,为竹笋夜蛾的精准防控提供了参考。     

三唑磷在竹笋中的残留分析与消解动态

运用气相色谱法分析了竹笋中三唑磷的残留量和消解动态,建立了三唑磷的消解动态方程。竹笋样品经乙腈匀浆、净化后,在DB-1701色谱柱中分离并采用GC-FPD分析,当添加水平为0.01~0.1 mg/kg时,竹笋中三唑磷的平均添加回收率为94.0% ~101.5%,相对标准偏差在1.6% ~18.2%之间,以3倍基线噪音作为最小检出限,得到最小检出量为5×10-12 g,最低检测浓度为 0.01 mg/kg。田间残留消解试验表明: 竹笋对三唑磷的吸收在施药后1 d达到高峰,之后缓慢下降,药后30 d接近最低检测浓度0.01 mg/kg,半衰期为3.7 d,消解到0.01 mg/kg的时间为药后30.2 d,其消解方程ct=2.738 5e-0.186 t。建议三唑磷在竹笋上的安全间隔期应大于21 d。     

苦竹熟笋护色研究

通过对护色效果的观察,确定护色液的成分和浓度为0 03%Z+2%T,最佳pH值为5,且笋体在护色液里浸泡时间为1h,这对于提高苦竹笋的加工品质和销售价值具有重要的意义。     

云南桔小寡鬃实蝇种群动态研究

经过水平和垂直地带的性诱观测与室内外调查试验，发现云南桔小寡鬃实蝇年发生４－５代。第二代为主害代，主要为害芒果、桃、番石榴等。成虫诱集高蜂期除柑桔点（高峰期为９－１０月）、甜橙点（高峰期为１０－１２月）外，蓁各点均在６－７月间。各年高峰期早晚和诱集量不同。同年各点成虫高峰期出现的时间也有差异，主要表现为从南到北高峰期推迟。冬季除昆明外，其它各点均可诱到成虫。以高温高湿的西双版纳数量最多。同一地区随     

关于江西省有机竹笋基地建设的建议

随着人们对环保生态食品的关注,有机竹笋的开发对人类健康的发展有着极其深远的意义。江西是全国竹子的重点产区,发展有机笋基地建设有着得天独厚的条件。本文综述了江西省有机竹笋的加工技术,出口贸易、保鲜技术的新趋势以及中国竹笋产业的进展;同时对江西有机竹笋基地建设提出了建议。