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斑点广翅蜡蝉(Ricania guttata Walker)寄主范围非常广泛,主要危害的是有"海岸卫士"美称的红树植物,此外还危害凤凰木(Delonix regia)等常见的园林植物。为了评估斑点广翅蜡蝉在广东省的潜在危害性,以制定科学的防治对策,该文参照国际通用有害生物分析的方法,从广东省适生分布情况、传播扩散和定殖可能性、潜在危害性、受害对象重要性、危险性治理难度5个方面进行了定性、定量风险性分析和综合评估。结果表明:斑点广翅蜡蝉在广东省的风险综合评估R值为1.30,属于低度危险林业有害生物。 相似文献
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柳尖胸沫蝉(Aphrophora costalis Matsumura)是危害柳树、杨树、果园、各种果树和苗圃和四旁绿化树种的重要害虫,近几年柳尖胸沫蝉对阿勒泰地区的杨柳科树种危害日益严重.对柳尖胸沫蝉进行初步生物学研究表明,在阿勒泰林区该虫1年发生1代,幼虫主要危害杨柳科树种的新生叶片,叶柄、嫩枝皮层,尤其若虫对柳树人工幼林、苗木危害严重,造成柳树死亡.查清了该类害虫的危害时期及危害程度,对其幼虫期采取综合性防治措施,开展环保性生物防治技术研究,为阿勒泰林业生态建设健康发展提供参考. 相似文献
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马占相思（Acacia mangium Willd）具有速生丰产、改良土壤、木材易加工等特点,是广东省一种主要的用材林造林树种,同时也作为道路绿化、生态工程林的主要配置树种,在广东省大部分地区广泛种植.特别是阳春市把马占相思作为发展商品林的当家树种,大面积营造,目前该市种植马占相思面积已超过2 万hm^2.但是近几年来在阳春市马占相思林中出现一种严重危害该种树种的害虫,造成大片林木落叶,严重影响生长或导致树木死亡.为此,笔者自2002年以来对该害虫进行了专门观察研究,经考证其种名为斑点黑蝉（Gaeana maculata）,又称黄点黑蝉,是同翅目蝉总科斑蝉属昆虫.现将有关观察研究结果介绍如下.
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蝉属同翅目蝉科，分为蚱蝉，又名“知了”，北方也叫“老啸”；鸣蝉又名伏了；褐斑蝉又名麦了三种。蝉在我国除高塞地区外，分布广泛，对各种果树和林木的危害非常严重。蝉对林木果树危害的特征是，刚孵化的幼若虫钻进土中，盘踞在树木的根系周围，靠吸食根系养分生长发育... 相似文献
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苹果斑点落叶病防治要点 总被引：2，自引：0，他引：2
苹果斑点落叶病主要危害叶片，并危害枝梢和果实。近年来在平山县果产区呈偏重趋势，可造成苹果落叶、落果、二次发芽、开花。严重削弱树势，降低苹果的产量和质量。主要防治要点如下： 相似文献
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Purely symbiotic and NO3-fed nodulated seedlings of Virgilia oroboides (Bergius) T.M. Salter, Cyclopia maculata (L.) Vent and Podalyria calyptrata Willd. were exposed to biologically effective ultraviolet-B radiation (UV-B) to assess the effects of above- and below-ambient UV-B on growth, symbiotic function and metabolite concentrations. Seedlings were grown outdoors either on tables under ambient or 34 or 66% above-ambient UV-B conditions (UV-B100 control, UV-B134 and UV-B166, respectively), or in chambers providing below-ambient (22% of ambient) UV-B (UV-B22) along with a UV-A control and a photosynthetically active radiation (PAR) control. Exposure of seedlings to UV-B166 radiation reduced (P < or = 0.05) leaf and stem dry mass by 34 and 39%, respectively, in C. maculata, and reduced leaf nitrogen concentration (%N) by 12% in V. oroboides. Nodule %N in C. maculata and stem %N in P. calyptrata also decreased (P < or = 0.05) in response to UV-B22 radiation compared with the UV-A control, but not compared with the PAR control. Concentrations of flavonoids, soluble sugars and starch were unaltered by the UV-B treatments. Application of 1 mM NO3 to UV-B166-treated seedlings increased whole-plant dry mass of V. oroboides and P. calyptrata by 47 and 52%, respectively. Dry mass of organs, nodule %N and total N concentration of these species also increased with NO3 application. However, NO3 supply decreased (P < or = 0.05) nodule dry mass, stem %N and leaf %N as well as root and leaf anthocyanin concentrations in C. maculata. In terms of UV-B x N interactions, dry mass of stems, roots, nodules and total biomass of NO3-fed C. maculata seedlings were reduced, and nodule %N, total N and leaf anthocyanins were depressed by the UV-B134 and UV-B166 treatments relative to UV-B100-treated seedlings. Although we found that above-ambient UV-B had no effects on growth and symbiotic function of V. oroboides and P. calyptrata seedlings, feeding NO3 to these species increased (P < or = 0.05) seedling growth. In contrast, purely symbiotic C. maculata seedlings were sensitive to the UV-B166 radiation treatment, and adding NO3 further increased their sensitivity to both the UV-B134 and UV-B166 treatments. 相似文献
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Seedlings of Eucalyptus maculata Hook (mesic environment) and E. brockwayi C.A. Gardn. (arid environment) were supplied 100, 70 or 40% of their water requirements estimated from leaf area and the water used by well-watered seedlings. Restricting water supply caused large differences in growth rates, which were related to large differences in total leaf area. There was a fivefold range of variation in number of leaves per plant, and a reduction of up to 20% in average leaf size as a consequence of restricting water supply. Eucalyptus maculata seedlings produced more dry matter than E. brockwayi seedlings, but net assimilation rate was higher in E. brockwayi seedlings. Transpiration rates were also higher in E. brockwayi than in E. maculata. Leaf expansion was analyzed as a function of water stress integral (S(Psi)), which is the cumulative integral over time of predawn water potential below a datum. The leaf area achieved at any stress level was not uniquely dependent on total S(Psi), there was a secondary effect associated with reduced leaf growth caused by previous stress. At any value of S(Psi), reductions in leaf growth of water-stressed seedlings relative to leaf growth of well-watered control seedlings were greater in E. maculata seedlings than in E. brockwayi. Treatment differences in both species showed that, within the levels of stress applied, a moderate water stress over a long period of time was more detrimental to dry matter production than a severe stress for a short time. 相似文献
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A new flavanone glycoside, 5,4'-dihydroxy-6-prenylflavanone 4'-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-rhamnopyranoside (1), was isolated from the seeds of Glircidia maculata. 相似文献
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本文分析了引自澳大利亚东部的桃金娘科伞房属4个树种或亚种在广东省德庆试验点的早期生长表现。结果表明：10年生时，4个树种或亚种生长量最大的是斑皮柠檬桉，其次是大叶斑皮桉(Corymbia henryi)、柠檬桉和斑皮桉，平均单株材积分别为0.2026、0.1748、0.1634和0.0526 m3；与8年生时比较，4个树种或亚种在10年生时仍保持较快的增长速度，材积增长均在15%以上。方差分析结果表明：试验组Ⅰ内，柠檬桉和大叶斑皮桉3个生长性状在家系间差异极显著(P＜0.01)；种源间胸径差异达显著水平(P＜0.05)，树高和单株材积无显著差异；在试验组Ⅱ，斑皮柠檬桉和斑皮桉的3个生长性状在树种或亚种、种源、家系间差异极显著(P＜0.01)。以单株材积高于对照为选择目标，选出柠檬桉3个种源4个家系，斑皮柠檬桉4个种源11个家系，大叶斑皮桉2个种源3个家系，共计9个种源18个家系，分别占参试种源和家系总数的50%和19.4%。 相似文献
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《Southern Forests》2013,75(3):179-185
Pendimethalin is used by some nursery managers to control weeds in Eucalyptus and Pinus seedbeds and cutting beds of Pinus. Six trials were implemented in open-rooted seedbeds to test the response of Pinus taeda to postemergence (to the crop) applications of 2.2 kg ha?1 active ingredient of pendimethalin (the formulation contained 455 g l?1). No stunting was noticed when treating seedlings with 2.2 kg ha?1 four to 10 weeks after sowing. In one study, treated seedlings were larger than those not treated. Although the 2.2 kg ha?1 rate provided good control of the prostrate weed Chamaesyce maculata, pine seedlings developed herbicide galls on the stem near the groundline. The frequency of herbicide galls at 2.2 kg ha?1 varied by study and ranged from 0 to 28%. At present, it is not known if the frequency of gall formation depends on environmental or genetic differences. 相似文献