共查询到20条相似文献，搜索用时 149 毫秒
1.
为给调控观赏桃花花期提供理论依据,研究了不同质量浓度的水杨酸(SA)在开花过程中对照手桃Prunus persica‘Terutemomo’开花的影响。在照手桃花前期及花中期进行SA喷施,测定其花芽、花蕾及枝条的可溶性糖含量、可溶性蛋白含量、C/N值及内源激素(GA、IAA、ZR、ABA)含量的动态变化。结果表明:2个时期SA各质量浓度处理使‘照手桃’的始花期推迟1~2 d,增强了开花过程中能量的储存,加快了可溶性蛋白的分解,增强了新陈代谢和激素活动,对开花有利。 相似文献
2.
3.
对蓖麻幼苗喷施不同浓度的植物生长调节剂(IAA、6—BA、GA3、KT),并以清水处理为对照,观测分析植物生长调节剂对蓖麻营养生长及生殖生长的影响。结果表明:100 mg/L的IAA、100~200 mg/L的6-BA、200 mg/L的GA3和100~200 mg/L的KT对蓖麻的地径和株高均有促进作用,KT则提早了始花期;IAA延迟了蓖麻的始花期,但提高了蓖麻花序总长度和雌花序的长度。其中200 mg/L IAA分别使花序总长度和雌花序长度增长了26.38%和56.17%。植物生长调节剂影响种子的大小和色泽,对种子含油率无明显影响。 相似文献
4.
5.
6.
7.
赤霉素(GA3)对八仙花花期及开花品质的影响 总被引：1，自引：0，他引：1
以八仙花为试验材料,研究了不同时间,不同浓度的赤霉素对八仙花的始花期、花径、开花数、枝长等的影响,结果表明:GA3可促进八仙花开花,浓度高开花早,可提前1-3天;250mg/L GA3明显增大八仙花花径,与对照比达到极显著水平;随着GA3浓度增加,八仙花的开花数和小花数都增加;不同时期对八仙花进行处理,也对八仙花提早开花有一定影响。对春、夏梢八仙花花期研究表明,夏梢八仙花观赏品质优于春梢八仙花,且夏梢八仙花种植周期短,更加经济,更利于广泛栽培。 相似文献
8.
不同化学疏花剂对桃坐果率和果实品质的影响 总被引：1，自引：0，他引：1
【目的】筛选适宜的桃化学疏花剂及其浓度,探究不同种类和浓度的化学疏花剂对桃坐果率及果实品质的影响。【方法】以3年生晚熟桃'秋甜'为试验对象,于盛花期喷施不同浓度的NAA、6-BA、石硫合剂3种化学疏花剂,以喷清水和自然坐果分别为对照,在果实采收时调查不同处理的坐果率和果实品质,研究不同处理对桃坐果率和果实品质的影响。调查的果实品质指标包括平均单果质量、果实纵径、果实横径、可溶性固形物含量、可溶性糖含量、可滴定酸含量等。【结果】与对照相比,喷施不同种类和浓度的化学疏花剂,'秋甜'桃坐果率均明显下降,且与NAA、6-BA、石硫合剂浓度呈负相关,即随其浓度的增加,坐果率明显下降。从保证产量和疏花疏果效果方面综合考虑,盛花期喷施20 mg/L NAA、0.2 g/L 6-BA或相对密度1.001 4 g/cm~3的石硫合剂效果较好,坐果率分别为24.04%、27.95%、26.63%。与对照相比,喷施不同种类和浓度的化学疏花剂均明显提高了平均单果质量。其中,以喷施相对密度1.002 8 g/cm~3的石硫合剂、20 mg/L的NAA、0.2 g/L的6-BA的平均单果质量较高,分别为388.54、384.56、380.12 g,且与其他处理差异显著。各处理均提高了可溶性糖含量,喷施20 mg/L NAA、0.2 g/L 6-BA或相对密度1.002 1 g/cm3的石硫合剂显著提高了可溶性固形物含量。喷施20、30 mg/L NAA或0.1、0.2 g/L 6-BA提高了可滴定酸含量。【结论】盛花期喷施20 mg/L NAA、0.2 g/L 6-BA对'秋甜'桃有较好的疏花效果,并且能提高果实品质。 相似文献
9.
草果花期喷施激素对其坐果率与产量的影响 总被引：2，自引：0，他引：2
通过对草果花期分别采用NAA(50 mg/L)、2,4-D(20 mg/L)、GA(100 mg/L)、6-BA(100 mg/L)、爱多收(水剂,0.67 mL/L)、矮壮素(水剂,670 mL/L)、芸苔素(2000 mg/L)和2,4-D钠盐(250 mg/L)喷施,以清水为对照,分析了不同激素处理对草果坐果率及产量的影响。结果表明,(1)激素(含对照)对坐果率、单果重、单花序轴产量均具有极显著的差异影响,草果花期喷施激素后坐果率、单花序轴产量和单位面积产量都高于对照;(2)喷施2,4-D、2,4-D钠盐、6-BA和矮壮素后单位面积产量达4909.05 kg/hm2、4723.20 kg/hm2、4127.40 kg/hm2和4038.30 kg/hm2,分别比对照(239.25 kg/hm2)提高了1951.74%、1874.03%、1625.04%和1 587.78%,其中喷施2,4-D为生产中提高草果产量的最适激素。 相似文献
10.
6-BA对蝴蝶兰不同品种开花的影响 总被引：1，自引：0，他引：1
采用不同浓度6-BA对蝴蝶兰不同品种进行处理,通过对其花蕾直径、始花期和盛花期的测定比较,结果表明:100mg/kg浓度的6-BA能显著地促进花蕾发育,品种间差异不显著;对始花期的影响因品种而异,浓度间和品种间差异均显著,品种2012用50mg/kg6-BA、75mg/kg6-BA、100mg/kg6-BA处理的植株比对照提前开花约4～5d;品种2022用75mg/kg6-BA和100mg/kg6-BA分别比对照提前3d和5d;品种2023,仅用100mg/kg6-BA使花期提前4d左右;6-BA能明显缩短盛花期,不同浓度间和品种间差异均显著。100mg/kg6-BA是促成栽培蝴蝶兰大红系的品种有效安全浓度。 相似文献
11.
《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
12.
《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
13.
Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
14.
《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
15.
《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
16.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
17.
Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
18.
《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 相似文献
19.
Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
20.
《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献