نتایج جستجو برای: weed infestation indices

تعداد نتایج: 103342  

ژورنال: علوم آب و خاک 2008
سید شریفی, رئوف , صدقی, محمد , راعی, یعقوب ,

  A factorial experiment, based on RCB design, with three replications was conducted to evaluate the effects of rhizobial inoculation, urea, and weeds on soybean performance in the field. The factors under study consisted of inoculation and non-inoculation, three levels of 0, 150, and 300 kg/ha urea, and weed-control and weed-infestation. Results showed that weed-control, inoculation and urea a...

2011
Asif Ali Jens Carl Streibig Svend Christensen Christian Andreasen

In order to reduce herbicide application an intelligent sprayer boom is being developed. It only sprays with herbicides if the weed infestation exceeds a certain weed control threshold. The estimation of leaf cover of weeds through image analysis is a prerequisite for the weed management model of the intelligent sprayer boom. Destructive and human perception methods of leaf cover estimation are...

2014
Zhuoxian He Xiaoqi Jiang Disna Ratnasekera Fabrizio Grassi Udugahapattuwage Perera Bao-Rong Lu

Increased infestation of weedy rice-a noxious agricultural pest has caused significant reduction of grain yield of cultivated rice (Oryza sativa) worldwide. Knowledge on genetic diversity and structure of weedy rice populations will facilitate the design of effective methods to control this weed by tracing its origins and dispersal patterns in a given region. To generate such knowledge, we stud...

Journal: :Molecular ecology 2007
Stéphane Fénart Frédéric Austerlitz Joël Cuguen Jean-François Arnaud

Gene flow is a crucial parameter that can affect the organization of genetic diversity in plant species. It has important implications in terms of conservation of genetic resources and of gene exchanges between crop to wild relatives and within crop species complex. In the Beta vulgaris complex, hybridization between crop and wild beets in seed production areas is well documented and the role o...

Journal: :حفاظت گیاهان 0
حمیدرضا محمددوست چمن آباد خاطره همتی مرتضی برمکی

breeding and cropping cultivars with high weed competitiveness have played an important role in the non-chemical weed management. this experiment was carried out in order to study the effect of nitrogen on weed tolerance and competition indices of five wheat cultivars at the research field of agricultural faculty, university of mohaghegh ardabili, during 2010-2011 growing season. experimental f...

2018
Ilias S. Travlos Nikolina Cheimona Ioannis Roussis Dimitrios J. Bilalis

Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community’s structure and the interactions among them, several population indices are used as key tool...

2014
Tewodros T. Wakie Paul H. Evangelista Catherine S. Jarnevich Melinda Laituri

We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial reso...

2013
José Manuel Peña Jorge Torres-Sánchez Ana Isabel de Castro Maggi Kelly Francisca López-Granados

The use of remote imagery captured by unmanned aerial vehicles (UAV) has tremendous potential for designing detailed site-specific weed control treatments in early post-emergence, which have not possible previously with conventional airborne or satellite images. A robust and entirely automatic object-based image analysis (OBIA) procedure was developed on a series of UAV images using a six-band ...

ژورنال: علوم آب و خاک 2007
محمدحسن راشدمحصل, , مهدی نصیری‌ محلاتی, , آسیه سیاه‌مرگویی, , علی اصغر محمدآبادی, , محمد بنایان اول, ,

This study was performed in two barley fields, in Experimental Station, Agricultural College of Ferdowsi University of Mashhad in 2003. Sampling was done by systematic method in which samples were taken from the corners of 7m*7m grids using 0.5m 0.5m size quadrates in three stages (pre herbicide, post herbicide and pre harvesting stages). The results indicted that the density of annual weed see...

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