共查询到20条相似文献,搜索用时 15 毫秒
1.
Dr. A. Abo-El-Nasr M. A. Sellam A. Abd-Elrazik M. Rushdi 《Journal of pest science》1981,54(9):135-138
Infection of sugarcane and maize plants with SCMV strain D and its substrains Da and De caused a makred decrease inleaf chlorophylls (A) and (B) while other pig-ments (xanthophyll and carotine) wer not markedley affected. SCMV isolates DcI (highly pathogenic), DVIII (moderately pathogenic) and DI (weakly pathogenic) caused a significant reduction in reducing, non-reducing and total sugars of infected sugarcane leaves. Infection of different sugarcane varieties with Dc I, D VIII and DI virus isolates increased invertase activity in stalks. The highly pathogenic isolate DcI induced highest enzyme activity folloed by moderately pathogenic isolate D VIII and finally weakly pathogenic isolate D I. 相似文献
2.
Wireworms (larval Elateridae) reduce the stand of newly planted sugarcane (complex hybrid of Saccharum spp.) directly by damaging growing points and indirectly by facilitating disease introduction. No research has evaluated resistance or tolerance of sugarcane genotypes grown in Florida to wireworm. Eleven genotypes of sugarcane and a S. spontaneum genotype were subjected to corn wireworm, Melanotus communis (Gyllenhall) (Coleoptera: Elateridae), in greenhouse experiments to evaluate potential host plant resistance. The experiments were designed to measure the effects of wireworms on the first 90 days of growth. Sugarcane stalk sections were planted in trays of soil with and without wireworms in 2010 and 2011. Stand count, dry weight, and percentage of nodes damaged were evaluated. Wireworms reduced stand and dry weight by 40–60 %. Several genotypes were able to produce acceptable stands in wireworm-infested trays by emerging quickly and producing many tillers. CP 88-1762, CP 89-2143, and CP 03-1912 did not suffer statistically significant losses of stand or biomass due to wireworms in either year. Our findings suggest that genotype resistance should be considered as an important component of an integrated program aimed at reducing the use of insecticides to control wireworms in sugarcane. 相似文献
3.
桉农间作系统土壤养分特征 总被引:3,自引:0,他引:3
主要对桉树大宽行条带方式种植的三年生桉农间作试验地土壤进行取样分析。对土壤养分研究表明:间作甘蔗、木薯和牧草在提高土壤有机质方面差异不大,但是在提高土壤全量N、P、K以及速效N、P、K上,间作甘蔗和牧草要优于间作木薯。其中,间作甘蔗和间作牧草全P和全N差异明显,而全K则和对照林地基本持平,速效N、P、K与对照林地相比,都有明显提高。间作木薯以提高全P为主,速效N和速效P也有一定幅度提高。 相似文献
4.
6.
7.
8.
The development of the red palm weevil, Rhynchophorus ferrugineus (Olivier) was investigated on a newly developed semiartificial diet as compared with two natural diets namely sugarcane stem and banana fruit. The weevil was successfully maintained on these diets and duration of the life cycle for males and females, respectively were 164.97 and 194.61 days on the semiartificial diet, 192.5 and 186.5 days on banana, and 172.00 and 170.00 days on sugarcane. The average egg production per female was shown to be significantly higher on the semiartificial diet, being 184.00?±?18.68 eggs compared with an average of 125.00?±?11.97 and 133.00?±?15.21 eggs on banana and sugarcane, respectively. The fertility ranged between 94?–?100?% in those eggs deposited by females previously reared on the tested diets. The developed semiartificial diet was shown to be suitable for maintaining laboratory colonies of the red palm weevil, and it can substitute natural diets. 相似文献
9.
对影响云南勐海甘蔗产量和糖分的气候因子近45年来的趋势性、阶段性和周期性的分析表明:影响甘蔗产量的气候因子中,3~10月的积温增加趋势显著;3~10月的积温和降水量有显著的阶段性;3~10月的积温、降水量、日照时数都有显著的振荡周期。影响甘蔗糖分的气候因子中,10~11月的平均最低气温增加趋势比较显著,有显著的周期性和阶段性;11月至次年2月的降水量有3~4年的振荡周期,趋势性和阶段性不显著。 相似文献
10.
Isabelle Dusfour Nicole L. Achee Ireneo Briceno Russell King John P. Grieco 《Journal of pest science》2010,83(1):41-46
Anopheles albimanus Wiedemann is one of the primary vectors of malaria in northern Belize. The primary breeding sites for this species in Central
America are fresh water wetlands that are found in close proximity to agriculture and, in particular, sugarcane fields. The
use of insecticides and herbicides on these crops leads to the introduction of chemicals into the surrounding wetlands. The
potential for the development of insecticide resistance is, therefore, quite high. A study was undertaken to obtain comparative
data on the resistance status of An. albimanus in northern Belize in relation to agriculture practices. Larval surveys were conducted at four collection points in marshes
juxtaposed to different crop types: Dubloon (DB)—control site located 300 m from any agriculture; Little Belize (LB)—mixed
crop agricultural with some human settlements; and Chan Chen (CC) and Buena Vista (BV)—year round sugarcane production. Time
mortality curves were obtained by exposing F1 larvae to DDT 1 μg/ml, malathion 1 μg/ml, and permethrin 0.05 μg/ml. Significant
differences in mortality rates from the four sites were observed only to malathion. The DB sites contained larvae that were
the most susceptible overall, in congruence with its distance from crops. Larvae from LB exhibited a medium level of tolerance.
Finally, the two populations collected at the edge of sugarcane fields (CC and BV) exhibited the highest tolerance to malathion.
These results represent first data on the impact of agriculture on the resistance status of malaria vectors in northern Belize.
The effect of malathion on An. albimanus insecticide resistance reinforces the concerns of the potential impact of agriculture usage on the efficacy of vector control
program. 相似文献
11.
基质配方对酸柚苗生物量及矿质元素含量的影响 总被引:1,自引:0,他引:1
为了筛选低成本的海南酸柚容器苗的基质配方,将海南的农业资源椰糠、甘蔗灰和菜籽饼与澄迈县当地表土按不同体积比配制9种基质,对酸柚苗进行容器育苗,研究不同基质配方对酸柚苗生物量指标(包括地上和地下部干鲜质量、根冠比)及矿质元素含量(包括地上及地下部的全氮、全磷、全钾、全钙及全镁含量)的影响。结果表明:不同基质配方对酸柚苗生物量指标的影响达极显著水平,其中T2(椰糠、表土和菜籽饼体积比4∶1∶1)、T5(椰糠、表土和菜籽饼体积比1∶1∶1)和T9(表土、甘蔗灰和菜籽饼体积比4∶1∶1)处理所育酸柚苗在生物量及矿质元素含量方面均表现良好,适合作为酸柚容器苗的栽培基质配方。 相似文献
12.
13.
以心叶球兰叶片为外植体,愈伤组织诱导和继代增殖培养基MS+6-BA2.0mg.L-1+NAA0.5mg.L-1+2,4-D1.0mg.L-1+GA1.0mg.L-1+白糖3%,诱导的愈伤组织多,生长旺盛,增殖倍数为2~3倍;丛芽诱导培养基MS+KT0.5mg.L-1+NAA0.5mg.L-1+GA1.0mg.L-1+白糖3%,芽的诱导率为79.3%;在丛芽增殖及复壮培养基1/2MS+IBA1.0mg.L-1+白糖2%上,有20%~30%玻璃化丛芽转为绿色苗,玻璃化单芽经复壮培养长成绿色苗;诱导生根培养基为1/2MS+IBA0.5mg.L-1+白糖2%,玻璃化生根率为56.4%,淡绿色苗生根率达91.1%。瓶苗移栽基质泥炭土∶珍珠岩∶甘蔗渣(1∶1∶1)的成活率最高,达91.4%。 相似文献
14.
Ricardo Ribeiro Rodrigues Tiago Egydio Barreto Cristina Yuri Vidal 《Forest Ecology and Management》2011,261(10):1605-1613
The complex interactions among endangered ecosystems, landowners’ interests, and different models of land tenure and use, constitute an important series of challenges for those seeking to maintain and restore biodiversity and augment the flow of ecosystem services. Over the past 10 years, we have developed a data-based approach to address these challenges and to achieve medium and large-scale ecological restoration of riparian areas on private lands in the state of São Paulo, southeastern Brazil. Given varying motivations for ecological restoration, the location of riparian areas within landholdings, environmental zoning of different riparian areas, and best-practice restoration methods were developed for each situation. A total of 32 ongoing projects, covering 527,982 ha, were evaluated in large sugarcane farms and small mixed farms, and six different restoration techniques have been developed to help upscale the effort. Small mixed farms had higher portions of land requiring protection as riparian areas (13.3%), and lower forest cover of riparian areas (18.3%), than large sugarcane farms (10.0% and 36.9%, respectively for riparian areas and forest cover values). In both types of farms, forest fragments required some degree of restoration. Historical anthropogenic degradation has compromised forest ecosystem structure and functioning, despite their high-diversity of native tree and shrub species. Notably, land use patterns in riparian areas differed markedly. Large sugarcane farms had higher portions of riparian areas occupied by highly mechanized agriculture, abandoned fields, and anthropogenic wet fields created by siltation in water courses. In contrast, in small mixed crop farms, low or non-mechanized agriculture and pasturelands were predominant. Despite these differences, plantations of native tree species covering the entire area was by far the main restoration method needed both by large sugarcane farms (76.0%) and small mixed farms (92.4%), in view of the low resilience of target sites, reduced forest cover, and high fragmentation, all of which limit the potential for autogenic restoration. We propose that plantations should be carried out with a high-diversity of native species in order to create biologically viable restored forests, and to assist long-term biodiversity persistence at the landscape scale. Finally, we propose strategies to integrate the political, socio-economic and methodological aspects needed to upscale restoration efforts in tropical forest regions throughout Latin America and elsewhere. 相似文献
15.
16.
亚硫酸盐预处理对蔗渣酶解效率的影响 总被引:1,自引:0,他引:1
为了破坏蔗渣的抗降解性,获得高的酶解效率,采用亚硫酸盐法对蔗渣进行预处理,探讨亚硫酸氢钠用量对蔗渣理化性质、表面磺酸基含量(磺化度)及酶解效率的影响,并进一步分析了磺化度对酶解效率的影响。结果显示:不同亚硫酸氢钠用量蔗渣的结晶度(I_(Cr))变化不显著,但预处理后蔗渣纤维素结晶区相对含量上升,半纤维素含量减少。50 g蔗渣,按固液比1∶8(g∶m L)加入1.1%的稀硫酸,亚硫酸氢钠加入量(以绝干蔗渣计)为8%,在160℃条件下反应30 min时制得的蔗渣其表面磺酸基最多,达131.73μmol/g。在2%干蔗渣,7.5 FPU/g(以干蔗渣计),50℃,72 h酶解条件下,对不同磺化度的蔗渣进行酶解,结果显示酶解效率随底物的磺化度升高而升高,最高综纤维素水解效率可达83.76%。研究表明:蔗渣的酶解效率与磺酸基团的含量呈正相关,而与蔗渣中纤维素的结晶度关系不明显;酸性亚硫酸盐法可除去绝大部分半纤维素,破坏蔗渣抗降解性,促进酶解效率。 相似文献
18.
Binderless particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse by steam-injection pressing and by using hot pressing as a reference method. The inner layer (core/pith) and
the outer hard fibrous layer (face/rind) of bagasse were used as raw materials. The effects of bagasse type, manufacturing
process, and storage method on the mechanical properties of binderless particleboards were investigated. The results showed
that the bagasse pith particles provided better board properties than bagasse rind particles. It seemed that bagasse pith
particles were more easily deformed than bagasse rind particles, enlarging the bonding contact area. The severe conditions
of steam-injection pressing caused delamination on the bagasse pith binderless boards with densities of 0.6 g/cm3 or higher, and gave poor bonding quality. However, steam-pressed boards showed relatively higher board properties than hot-pressed
boards. The storage method of sugarcane bagasse affected the chemical composition and the board properties. It was shown that
the extent of self-bonding formation depends on the chemical and morphological properties of lignocellulosic materials, as
well as on the manufacturing conditions.
Part of this paper was presented at the 5th International Wood Science Symposium, Kyoto, Japan, September 2004 相似文献
19.
20.
Poplar (Populus deltoides Bartr.) based agroforestry systems are economically viable and more sustainable than many other crop rotations prevalent
in northern India. Growth {girth at breast height (GBH) and height} and productivity (volume) of clone G-48 of poplar spaced
at 5 x 4 m, soil organic carbon (OC), and concentration of available macronutrients (N, P and K) and micronutrients (Zn, Fe,
Mn and Cu) in surface soil (0-15 cm depth) were determined at an interval of six months starting from April 2002 till October
2003 in one and four year old (in January 2002) 16 poplar plantations on farmers' fields in Ludhiana, Punjab. The observations
were taken from plantations having fodder {sorghum (Sorghum bicolor)/pearlmillet (Pennisetum americanum) in summer}-wheat
(Triticum aestivum) (in winter) rotation throughout the poplar age and those having sugarcane (Sachharum officinarum) initially
during two years and fodder-wheat rotation thereafter. The GBH, height and volume of younger plantations intercropped with
fodder-wheat rotation were 15.6, 17.2 and 46.7%, respectively higher than that of plantations intercropped with sugarcane.
Growth increment of poplar was markedly higher during April to October than October to April. Soil OC was significantly greater
in older (6.83 g kg-1) than the younger (5.35 g kg-1) plantations. Available macronutrients in soil increased at successive
sampling times. The average Zn concentration at final sampling was 17% lower compared to initial sampling, whereas the other
micronutrients tended to increase during April 2002 to October 2003 and the increase was higher in four year old plantations
than one year due to higher inputs of organic matter. 相似文献