共查询到19条相似文献，搜索用时 468 毫秒
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对1年生长柄扁桃苗圃杂草进行了10种除草剂茎叶处理,结果表明:苗圃中的杂草以藜科和禾本科为主,所有除草剂处理对藜科杂草均有防除作用,14%草除灵、10.8%盖草能、12.5%拿扑净、48%排草丹、10.8%高盖+48%排草丹、12.5%拿扑净+48%灭草松、50%异丙隆对禾本科杂草的防效率较高,其中,50%异丙隆的杀草谱最广。48%灭草松和12.5%拿扑净+48%灭草松处理的杂草防效率高,但其对苗木的为害严重。高剂量10.8%盖草能和12.5%拿扑净处理下,杂草防效率达到了68%和56%,长柄扁桃苗未表现出药害症状,二者适用于长柄扁桃苗圃杂草的防治。 相似文献
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在榆林市樟子松2年生和4年生营养钵苗圃,选用3种除草剂、2种混剂及其不同剂量,进行了除草效果试验,结果为在除草高峰期施药后30d左右,试验处理的除草率为51.3%~96.9%,2种混剂各自的平均除草率都高于单个药剂,单个药剂的平均除草率23.5%割地草最高;除草剂及其混剂达到一定浓度后会对培育的苗木产生伤害,与单独用药相比,混合用药发生药害的剂量较小,适宜最大剂量为23.5%割地草1 350ml·hm~(-2)、12.5%拿捕净1 500ml·hm~(-2)、10.8%盖草能900ml·hm~(-2);2a生苗圃混合用药的致害剂量低于4a生苗圃,23.5%割地草+12.5%拿捕净、23.5%割地草+10.8%盖草能各药剂最大适宜剂量2a生苗圃分别为450ml·hm~(-2),4a生苗圃分别为750ml·hm~(-2);综合考虑,2a生樟子松苗圃地应优先选用的药剂及其适宜剂量为23.5%割地草,2a生苗圃地750~1 350ml·hm~(-2),4a生苗圃地1 800ml·hm~(-2);混合药剂23.5%割地草+12.5%拿捕净,23.5%割地草+10.8%盖草能,适宜剂量为2a生苗圃地各药剂300ml·hm~(-2),4a生苗圃地各药剂750ml·hm~(-2)。 相似文献
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果尔混合除草剂的苗圃除草试验 总被引：1，自引：0，他引：1
留换床苗木选用果尔与盖草能、拿扑净等混合果尔除草剂能杀死苗圃绝大多数宽、窄叶杂草,杀死率在90%以上;采用以果尔为主剂的除草剂除草比手工除草每公顷降低成本127.2元。 相似文献
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豆田禾本科杂草发生量大,消耗地力,影响大豆正常生长,降低产量.人工除草,费工费力.拿扑净是杀禾本科杂草的除草剂,对双子叶植物安全. 相似文献
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通过几年的试验研究,筛选几种化学除草剂和其最佳剂量;针对大行距针叶树圃地,采用草甘膦防除冰草,同时配伍2,4-D丁酯兼杀其它阔叶杂草;针对小行距针阔叶树苗圃地,采用盖草能或者禾草克防除冰草等禾本科杂草,同时配伍果尔兼杀其它阔叶杂草;土壤处理剂采用氟乐灵作杂草发芽前处理。 相似文献
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封闭型除草剂在育苗生产中的应用 总被引：1，自引：0，他引：1
除草是苗圃的一项重要工作,因此必须本着"除早、除小、除了"的原则,有效清除杂草。除草方法有人工除草和化学除草。实践证明,化学除草法中的封闭除草法是一项经济实用、行之有效的除草方法。一、封闭型除草剂应用试验1.封闭型除草剂的选择。封闭型除草剂的种类较多,目前苗圃中常用的封闭型除草剂有拿捕净、果尔、乙草胺、异丙草胺、西玛津、氟乐灵、阿特拉津等,应根据不同除草剂的功用和不同苗木品种的特性有针对性地加以选用。一般来说,针叶树 相似文献
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Bárbara Cuesta Pedro Villar-Salvador Jaime Puértolas Douglass F. Jacobs José M. Rey Benayas 《Forest Ecology and Management》2010
We analysed the physiological bases that explain why large and high nitrogen (N) concentration seedlings frequently have improved survival and growth relative to small seedlings in Mediterranean woodland plantations. Large seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L.) with high N concentration (L+), and small seedlings with either high (S+) or low (S−) N concentration, were planted on two sites of different weed competition intensity that created contrasting stress conditions. Seedling survival, growth, gas exchange, N remobilization (NR) and uptake (NU), and water potential were assessed through the first growing season. Weeds reduced survival and growth, but seedling response to weed competition varied among phenotypes and between species. At the end of the first growing season, L+ Aleppo pine seedlings had higher survival than both small seedling types in presence of weeds but no differences were observed in absence of weeds. Mortality differences among phenotypes occurred in spring but not in summer. L+ Aleppo pines grew more than small Aleppo pines independently of weed competition. No holm oak seedling type survived in presence of weeds and no mortality differences among phenotypes where observed in absence of weeds, although L+ holm oak seedlings grew more than small seedlings. Mortality and growth differences in Aleppo pine were linked to marked physiological differences among phenotypes while physiological differences were small among holm oak phenotypes. L+ Aleppo pines had greater root growth, gas exchange, NR, and NU than small seedlings, irrespective of their N concentration. Seedling size in Aleppo pine had a greater role in the performance of transplanted seedlings than N concentration. The functional differences among oak phenotypes were small whereas they were large in pine seedlings, which led to smaller differences in transplanting performance in holm oak than in pine. This suggests that the nursery seedling quality improvement for planting in dry sites could depend on the species-specific phenotypic plasticity and functional strategy. Improved transplanting performance in large Aleppo pine seedlings relative to small seedlings was linked to greater gas exchange, root growth and N cycling. 相似文献
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Growth and production varies between pair-wise mixtures and monoculture plantations in North Viet Nam 总被引：1，自引：0，他引：1
The potential benefits of species mixture were investigated using pair-wise comparisons of four timber tree species in northern Viet Nam. Chukrasia tabularis, Canarium album, Michelia mediocris and Eucalyptus urophylla were grown in monocultures and in pair-wise mixtures. The trial was established as a randomized block design with each treatment replicated four times. Volume production gain or loss in mixtures was assessed by calculating a mixture index, which is defined as Relative Yield Total (RYT). At age 48 months, the trial indicated mixed performance with both positive and negative impacts of growing some species in mixtures compared to monocultures. The largest gain was shown in the mixture of a shade-intolerant species, Chukrasia with a more shade-tolerant species, Michelia (47% gain in relative yield), and Eucalyptus with Michelia (45% gain in relative yield) at the first 38 months. The other three mixtures tested, and which were not successful (i.e. had lower relative yields) at 38 months, was the mixture of all shade-intolerant species, including Chukrasia with Canarium, Canarium with Eucalyptus and Chukrasia with Eucalyptus. This suggests that species with different shade tolerances can form complementary pair-wise mixtures, but this changed significantly (P < 0.05) over the following 10 months. At age 48 months the RYT of Chukrasia with Michelia increased by 12%, those of Michelia with Eucalyptus decreased by 20% at 48 months compared to 38 months, suggesting that Eucalyptus should be thinned at around year 5 years. Likewise, the RYT of Michelia with Canarium declined significantly by 23% at 48 months. The RYT of other tested mixtures remained almost unchanged over time. 相似文献
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Eucalyptus saplings are sensitive to weed competition. This can cause water stress which is the most important abiotic factor limiting survival during plantation establishment. Two provenances of Eucalyptus globulus subsp. maidenii viz. Murrabrine and Tantawanglo were used to examine the effect of water stress induced by weed presence during establishment on physiological responses of young saplings. Six-month-old saplings were transplanted into 220-L containers containing three weed cover levels (no weeds, low weed density, high weed density). Each provenance × weed cover combination was assigned to either a high or a low water availability level. Sapling water status was affected differentially by water competition induced by weeds. Murrabrine provenance showed higher pre-dawn relative water content, pre-dawn leaf water potential and noon leaf stomatal conductance than Tantawanglo. Water stress conditions induced osmotic (πadj) and elastic (?adj) adjustments. The magnitude of πadj varied according to the weed cover and water availability. Weed presence produced cell wall stiffening independently of water availability. Murrabrine provenance was less sensitive to weed cover, showing a significant change in wall stiffening only under high weed density. The two provenances had similar drought-tolerance mechanisms, but different responses to stress. Murrabrine had a larger water stress threshold than Tantawanglo that combined processes for “reduced water loss” and “maintenance of water uptake”. The relative importance of induced physiological drought-tolerance in response to weed interference during establishment is discussed. 相似文献
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在重庆市城口县咸宜乡苗圃和中国林科院温室开展崖柏扦插繁殖试验,研究采穗母树年龄、不同激素种类及其组合、激素浓度、扦插基质、物理促根等不同处理方式下崖柏扦插生根效应.结果表明:(1)在咸宜乡苗圃,采用自动喷雾设施,以蛭石-泥炭土-珍珠岩(1∶1∶1)为扦插基质,用3种激素和清水处理崖柏幼树1年生枝条,扦插后160d的生根率为74.76％～96.70％,不同处理组合生根效应具有显著差异,2000 mg· L-1 IBA＞清水对照(CK)＞1 000mg·L-1 IBA＞1 000 mg·L-1IBA+ 500 mg· L-1NAA;(2)在林科院温室用2种激素和清水处理崖柏幼树1年生枝条,扦插于蛭石-泥炭土-珍珠岩(1∶1∶1)的基质,搭塑料拱棚,扦插后120 d的生根率远低于咸宜乡苗圃,为25.93％～45.37％,激素处理后的枝条与对照差异显著,1 000 mg·L-1 IBA+ 50 mg·L-1 NAA=2 000 mg·L-1 IBA＞清水对照(CK);(3)在咸宜乡苗圃用不同激素和物理促生根方法组成的27种组合处理的成年崖柏枝条,最高生根率仅为20.83％.生根率超过10％的处理组合是:清水处理,泥炭土∶蛭石∶珍珠岩(1∶1∶1);1 000 mg·L-1IBA+500 mg·L-NAA,泥炭土∶珍珠岩(2∶1);1 000 mg·L-1IBA,泥炭土∶蛭石∶珍珠岩(1∶1∶1),流水冲洗. 相似文献
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从落叶松梢栖真菌筛选出对落叶松枯梢病病原菌有抑制作用的菌株,对落叶松枯梢病进行生物防治。将自落叶松梢部分离到的11种梢栖真菌与落叶松枯梢病病原菌进行对峙培养,根据被覆盖程度、抑菌率、拮抗系数和防治预试验的结果,综合评价后发现:粪生粪壳、深绿木霉和球毛壳3种梢栖真菌对落叶松枯梢病有良好的拮抗作用。利用这3个菌株在黑龙江省勃利县通天一林场国富沟进行林间防治试验,结果表明:防治效果为粪生粪壳>代森锰锌400倍液>深绿木霉>球毛壳;深绿木霉和粪生粪壳喷洒浓度50%和球毛壳喷洒浓度75%时,真菌多样性最多,梢栖真菌系统较其他浓度更为稳定,与化学防治相比,既达到了防治目的又具有不污染环境的优势。 相似文献
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It has become apparent that some interventions are required to aid the regeneration of woody species in the Sudanian savanna. Direct seeding has been ineffective, thus planting high quality seedlings may be a viable alternative. In this study, we examined the stock quality of two valuable Sudanian savanna species, Acacia macrostachya and Pterocarpus erinaceus. Different nursery production periods were tested as well as the species’ field performance under well-watered and stressed conditions. The results showed that older seedlings (9-month) were morphologically distinct from younger ones (3-month), particularly in the case of P. erinaceus. Eighteen months after planting out, survival and growth of seedlings were not affected by initial seedling size; this was the result of the high root to shoot ratio of seedlings in all age groups at the time of planting. Seedling mortality as high as 30% was observed and attributed to both drought stress and other factors such as herbivory. Regression analyses revealed that initial shoot height was a poor predictor of field performance for both species, but initial root collar diameter accounted for 25% of the variation in diameter of P. erinaceus in the field. We conclude that initial seedling size does not affect survival and growth in the field provided that all sizes of seedling have a high root to shoot ratio at the time of planting. The prediction of field performance could be improved by developing a model that incorporates a wide range of root collar diameter. 相似文献
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Overexploitation of the African mahoganies, Khaya anthotheca and K. ivorensis, could lead to their commercial extinction in the near future. Efforts to establish plantations to sustain supply have been discouraged by the shoot borer Hypsipyla robusta Moore. We hypothesized that there is a shade level at which Hypsipyla attack and branching are reduced, but height growth is adequate. We report on the growth of these African mahoganies and Hypsipyla attack under three different forest canopy shade levels: open (55% open sky), medium shade (26% open), and deep shade (11% open). Hypsipyla attack on K. anthotheca was 85%, 11%, and 0% attack in the open, medium, and deep shade treatments, respectively. However, growth in medium and deep shade was slow. Mean tree height for K. anthotheca was 413.8, 126.2, and 54.5 cm in the open, medium and deep shade treatments, respectively. K. ivorensis showed similar trends. The reduced growth under these shade levels limit the use of this strategy for controlling Hypsipyla attack. 相似文献