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81.
面向对象的多时相HJ星影像甘蔗识别方法   总被引:5,自引:1,他引:4  
广西甘蔗种植区域离散,因混杂于多种农作物中,其光谱易受其他作物的影响,故利用单一时相多光谱遥感影像提取甘蔗有一定的困难。针对这一难题,该文首先提出甘蔗最佳识别时段,基于多时相HJ-1A/1B星CCD影像,以广西中部贵港市三区为研究区,通过面向对象分类软件eCognition,利用甘蔗在不同时相影像上的光谱特征:光谱均值、归一化植被指数NDVI和由灰度共生矩阵导出的局部一致性指数GLCM homogeneity,建立决策树逻辑的分类规则集提取甘蔗种植区。结果表明该方法能较精确地进行甘蔗识别,最大程度消除其他干扰因素影响,分类精度为91.3%,kappa系数为0.83,同时也证实了HJ卫星CCD多光谱遥感数据应用于甘蔗识别的有效性。  相似文献   
82.
侧柏球花的发端发育及物候学   总被引:1,自引:0,他引:1  
侧柏营养技端4月下旬萌动,5~10月为营养生长期,10月以后休眠。7月中旬至8月上旬,长日照中日照惭短的时期,营养枝端转化为生殖枝端。雄球花端圆球形,雌球花端圆柱状。8~10月为球花发育期,10月进入休眠。翌年3月末传粉受精,10月初球果成熟。成熟的雌球花枝较雄球花枝长,90°弯曲。雌球花数量少,多着生在当年生枝条基部近轴面的侧枝上。对侧柏球花发端的时间、特点和其他针叶树种进行比较与讨论。  相似文献   
83.
连续三年进行活体观察。本文较为全面地报道了杉木小孢子发生与花粉发育的研究结果:1.阐明了减数分裂的发生及各阶段的持续时间。2.确定杉木小孢子发生的物候学属Eriksson的第三种类型。3.估计杉木染色体的DNA含量为0.368.PgDNA/μ。4.发现花粉发育过程中淀粉粒的消长规律与细胞质团的形成及其定向移动。5.首次描述了杉木花粉有丝分裂的动态过程。  相似文献   
84.
Abstract

One of the problems in obtaining high wheat yield is the unavailability of micronutrients in balanced quantities. Zinc is an essential micronutrient due to its involvement in many metabolic processes in plant. In this experiment, seeds of two wheat cultivars (Faisalabad-2008 and Lasani-2008) were subjected to soak in aerated Zn solution of 0.1 and 0.01?M for 12?hr. For the seed coating, Zn was adhered to the wheat seeds by using Arabic gum by using zinc sulfate (ZnSO4·7H2O) as a source. Untreated dry seeds were considered as a control. Results indicated that field emergence was improved by Zn seed treatments, maximum numbers of seedlings were observed in seed priming with 0.01?M Zn solution. Seed osmoprimed with 0.01?M Zn solution improved the grain yield, biological yield, and other yield related traits. Grain and straw Zn enrichment were also enhanced in seed osmoprimed with 0.01?M Zn solution.  相似文献   
85.
Abstract

Five old shrub rose taxa were studied in field experiments in northern Finland during the years 1993–1999. The plant material was micro-propagated from woody plants selected for their ornamental value and hardiness for northern areas of Finland. The observations in the experiments were based on phenological monitoring and survey of plant success. The results revealed significant differences in the success of the different rose genotypes, and the most valuable genotypes were identified. Micropropagation was successfully used as a propagation method and these in vitro propagated roses grew naturally under harsh field conditions. The Rosa ‘Tornedal’ origins, R. ‘Poppius’ and R. ‘Sipi’ were ranked the most suitable cultivars for northern landscaping. Overall, all of the studied roses succeeded fairly well.  相似文献   
86.
This work was performed in the Rio de Janeiro State, Brazil, with the objective to evaluate the nutritional status of yellow passion fruit plants along different phenological stages, using the DRIS method. Fifty-four passion fruit cultivated areas with an annual yield productivity ranging from 6.95 to 33.8 t ha?1 year?1 and average productivity of 16.9 t ha?1 year?1 were selected in the region. The contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chlorine (Cl), iron (Fe), zinc (Zn), manganese (Mn), and boron (B) were evaluated. The reference standards were established (mean and variation coefficient) for the values of the nutrient concentration ratios, two by two, on samples from high yield productivity plantations and analyzed by the DRIS index of nutrients for the medium and low yield productivity areas. The established standards differed according with the phenological stage of the culture. In a general way, the mean content of the evaluated nutrients did not differed between the two productivity levels into each phonological stage. There was a difference for the Nutritional Limitation Order between different phenological stages of yellow passion fruit plants. The most negative DRIS indexes and the highest absolute values for the Average Nutritional Balance on yellow passion fruit plants in the region, were found for potassium in May, phosphorus in October and iron in January.  相似文献   
87.
Snow cover is an important water source for vegetation growth in arid and semi-arid areas,and grassland phenology provides valuable information on the response of terrestrial ecosystems to climate change.The Mongolian Plateau features both abundant snow cover resources and typical grassland ecosystems.In recent years,with the intensification of global climate change,the snow cover on the Mongolian Plateau has changed correspondingly,with resulting effects on vegetation growth.In this study,using MOD10A1 snow cover data and MOD13A1 Normalized Difference Vegetation Index(NDVI)data combined with remote sensing(RS)and geographic information system(GIS)techniques,we analyzed the spatiotemporal changes in snow cover and grassland phenology on the Mongolian Plateau from 2001 to 2018.The correlation analysis and grey relation analysis were used to determine the influence of snow cover parameters(snow cover fraction(SCF),snow cover duration(SCD),snow cover onset date(SCOD),and snow cover end date(SCED))on different types of grassland vegetation.The results showed wide snow cover areas,an early start time,a late end time,and a long duration of snow cover over the northern Mongolian Plateau.Additionally,a late start,an early end,and a short duration were observed for grassland phenology,but the southern area showed the opposite trend.The SCF decreased at an annual rate of 0.33%.The SCD was shortened at an annual rate of 0.57 d.The SCOD and SCED in more than half of the study area advanced at annual rates of 5.33 and 5.74 DOY(day of year),respectively.For grassland phenology,the start of the growing season(SOS)advanced at an annual rate of 0.03 DOY,the end of the growing season(EOS)was delayed at an annual rate of 0.14 DOY,and the length of the growing season(LOS)was prolonged at an annual rate of 0.17 d.The SCF,SCD,and SCED in the snow season were significantly positively correlated with the SOS and negatively correlated with the EOS and LOS.The SCOD was significantly negatively correlated with the SOS and positively correlated with the EOS and LOS.The SCD and SCF can directly affect the SOS of grassland vegetation,while the EOS and LOS were obviously influenced by the SCOD and SCED.This study provides a scientific basis for exploring the response trends of alpine vegetation to global climate change.  相似文献   
88.
为量化水分胁迫引起的花生物候学变化及其对开花和果针生长的效应,在阿根廷科尔多瓦省农牧学院试验农场开展了本研究。试验分两年(1997/98,1998/99)实施,随机区组设计,重复3次。试点为典型的Hapludol土,品种为Florman INTA,行株距分别为0.7和0.08m。在不同的生长时期(Rl—R3,R3—R4,R4—R6,R6—R7)施以干旱处理(人工遮雨),持续时间为18—22d不等。测量土壤含水量并统计单株花朵数和果针数。结果证实了先前关于花生开花量和果针数对水分胁迫的反应的报道,也支持生殖生长延迟以及荚果发育和种子充实后期易受霜害的假说。  相似文献   
89.
90.
《夏小正》是中国现存最早的气候物候历,书中记载了大量的植物物候信息。植物考证可以解决历代注释中植物名莫衷一是的问题,客观认知早期农业发展和植物的关系,同时有助于重建历史时期的气候变化。《夏小正》中共记录29种植物,除一种存疑外,其他隶属17科26属,其中木本植物占31%,草本植物占69%,禾本科和菊科出现的植物最多,水生植物和湿生植物占据一定的比重。蓼蓝、芸苔、韭、桃、杏、枣等植物的栽培首次见于文献,反映了该时期的农业技术已初具规模;大部分植物具有较强的实用性,主要作为早期先民的食物、香料、染料、木材以及衣物原料。  相似文献   
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