室内观赏净化用草坪草栽培基质的选择研究

通过对用于室内观赏净化的冷季型草坪草紫羊茅和多年生黑麦草的草坪草高度、修剪量、叶宽、密度、草坪颜色和均一性等外观质量指标的测定,进行无土栽培基质的选择研究。结果表明:处理4(黑草炭1.2L+蛭石0.3L+陶粒0L)的基质不适合室内草坪的栽培。处理1(黑草炭0.3L+蛭石0.75L+陶粒0.45L),处理2(黑草炭0.6L+蛭石0.6L+陶粒0.3L)的基质配方最适合紫羊茅室内生长;多年生黑麦草在试验基质范围内均变黄,试验范围内基质没有适用于多年生黑麦草室内栽培。     

不同保鲜剂对月季切花保鲜生理初探

实验探讨了不同浓度保鲜剂对月季切花‘粉后'的花径、花枝鲜重变化率、花瓣可溶性糖含量及丙二醛(MAD)含量的影响.结果表明:Ⅵ处理(10%蔗糖+200mg·L-18-HQ+75 mg·L-1GA3+25 mg·L-16-BA)保鲜效果最好,平均花径最大,花枝鲜重变化率最高、花瓣可溶性糖含量及丙二醛(MAD)含量最低.     

The effect of Holistic Planned Grazing™ on African rangelands: a case study from Zimbabwe

Holistic Planned Grazing? (HPG) is purported to have positive long-term effects on rangelands, enhancing ecosystem services. Given comparable environmental templates, but different management regimes, vegetation monitoring and landscape function analysis showed the Africa Center for Holistic Management (ACHM) at Dimbangombe had a significantly higher rangeland condition (composition, cover, standing crop and soil health) than adjacent Sizinda (SCR) and Monde (MCR) communal rangelands. Overall grazer density on ACHM is 42% higher than that of SCR (no data for MCR). Finer-scale satellite collar data for ACHM yielded a calculated stocking rate of 0,55 LSU ha^-1 y^-1 or 24 590 kg km^-2, which constitutes high-density grazing. An energy flow estimate shows that the grazing resource would, on average, not be limiting for livestock on ACHM but limiting on SCR. HPG may include an element where kraals are inserted into degraded rangelands for a short period. Overall, ACHM shows stable perennial composition with smaller tufts significantly closer together. A similar result was visible in SCR where maize yields were visibly higher on kraaled areas than on adjacent untreated fields. HPG yields positive long-term effects on ecosystem services (soils and vegetation) and points to the HPG approach enhancing the sustainability of livestock and wildlife in this environment.     

pH值对黄瓜子叶雌花诱导中的生理生化影响

研究外源激素KT和IAA和pH值对离体黄瓜子叶雌花诱导中的叶绿素a、叶绿素b、可溶性蛋白质、可溶性糖和淀粉的影响.结果表明:KT 3.0 mg/L、LAA 0.05 mg/L,pH 6.2时,叶绿素a、可溶性蛋白质、可溶性糖含量均达到峰值,淀粉含量此时达到最低,雌花诱导率为35%,达到最高.并发现叶绿素a、叶绿素总量(a b)、可溶性蛋白质、可溶性糖含量与雌花诱导率成正相关.     

Establishing targeted control of creeping perennial weeds with soil‐active chemical injections: Assessment of subterranean bud responses in contact

Increased infestation of aggressive creeping perennial weeds is a significant problem in urban vegetation management programs. These weeds produce vigorous biomass and extensive underground networks of either rhizomes or creeping roots that easily regrow from numerous buds. Foliar application of proper systemic herbicides has been a most effective way to suppress regrowth from underground creeping organs; however, killing the mature plants has disadvantages from aesthetic, economic, and ecological viewpoints. Therefore, we intended to test the possibility of soil‐injection of soil‐active herbicides for effective control of the perennial weeds which develop underground network systems. A pot experiment using combinations of seven species (seven rhizomatous and two having creeping roots) and five chemicals (four herbicides and a plant growth regulator) was conducted to assess whether and how chemicals diffused in soil affect the sprout and growth of buds on creeping organs. All the tested herbicides completely inhibited bud sprouting in one and more species when applied at median or high rates, while most of the flurprimidol‐applied segments sprouted but shoot elongation was significantly reduced. Characteristics of each herbicide were also reflected in the selectivity and features of new outgrowth. The results indicated that chemicals existing in soil were undoubtedly absorbed and affected bud activities. It is concluded that soil injection that delivers the probable soil‐active chemicals to subterranean creeping systems could be a promising technology for controlling noxious creeping perennials.     

Land suitability assessment for perennial crops using remote sensing and Geographic Information Systems: A case study in northwestern Egypt

Abstract

The main objective of this study was to develop a Geographic Information Systems-based model for land suitability assessment for guava, olive and date palm in the North-western coast of Egypt. Soil, climatic and landscape database as well as satellite image have been integrated through Geographic Information Systems (GIS). A Landsat ETM+ image dated 2001, was classified using maximum likelihood classifier to produce land use/land cover map. Physical and chemical analyses of 57 soil profiles were interpolated to produce continuous land characteristic maps that are relevant to the requirement of the considered crops. These maps with climate and land cover map were integrated using GIS to produce land suitability maps for guava, olive and date palm. Two types of land suitability maps were produced in this study namely: Continuous land suitability maps and conventional land suitability classified maps. For each of them six land suitability maps were produced for the three crops in which three are for actual land suitability and the other three for potential land suitability. It was found that the suitability was higher for date palm followed by olive and the lowest suitability was assigned for guava.     

Sensitivity of Cirsium arvense to simulated tillage and competition

Abstract

Single and combined effects were studied of root length, burial depth, cutting and competition from a seasonal green manure crop on the growth and development of C. arvense from roots found in the upper soil layer. The experiment was performed under field conditions and partly repeated in a green house. The green manure consisted of a mixture of phacelia, common vetch, red clover and Italian ryegrass. Root fragments of 5 and 10 cm length were buried at 5 and 15 cm soil depth, simulating soil tillage. Use of green manure alone reduced growth of C. arvense more than any other single factor (81–99%), while root length and burial depth were more variable in their effect (0–96% reduction). Combined treatments involving both green manure, deep root burial (15 cm) and short root length (5 cm) reduced growth of C. arvense consistently by 95–100%. At the minimum regenerative capacity of C. arvense the number of leaves was 3–7 in plots with no green manure, at which time cutting had the greatest effect on regrowth the following year. The level for minimum regenerative capacity was not possible to decide for C. arvense growing in competition with green manure. Combined multiple treatments in spring, including use of green manure and mechanical operations in the upper soil layers, appear to be a potential means of reducing C. arvense infestations.     

Effect of developmental stage on carbohydrate accumulation patterns during winter of timothy and perennial ryegrass

Abstract

Changes in non-structural carbohydrates before and during winter are one of the major plant responses to winter stress. However, the observed pattern of changes is variable, not only between grass species but also between different experiments. This study examined the effect of developmental stage on carbohydrate reserves during winter in two grass species differing in winter hardiness.

Timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.), sown early or late in the growing season, were sampled for total non-structural carbohydrates (TNC) in late October (end of main growing season), and then in late January, early March and late April. Quantitative and qualitative patterns of carbohydrate accumulation in crown segments were influenced both by plant genotype and developmental stage of the plants prior to winter. TNC increased from October to March, demonstrating considerable cell activity during winter, and declined to their lowest level in April. Sucrose proved to be the major reserve carbohydrate, followed by fructans. The highest content of TNC was found in the most winter-hardy cultivars, particularly in January and March. Early-sown plants accumulated higher levels of fructans than of sucrose, whereas late-sown plants mainly accumulated sucrose. These differences persisted during the winter. It can be concluded that the pattern of carbohydrate accumulation during winter differed between the two species studied and it was strongly affected by both cultivar and plant-developmental stage.