نتایج جستجو برای: crop model

تعداد نتایج: 2162593  

Journal: :Remote Sensing 2017
He Li Zhongxin Chen Gaohuan Liu Zhiwei Jiang Chong Huang

To improve the accuracy of winter wheat yield estimation, the Crop Environment Resource Synthesis for Wheat (CERES-Wheat) model with an assimilation strategy was performed by assimilating measured or remotely-sensed leaf area index (LAI) values. The performances of the crop model for two different assimilation methods were compared by employing particle filters (PF) and the proper orthogonal de...

Journal: :تحقیقات اقتصاد و توسعه کشاورزی ایران 0
حبیب اله سلامی استاد اقتصاد کشاورزی دانشکدة اقتصاد و توسعة کشاورزی، دانشگاه تهران تکتم محتشمی استادیار دانشگاه تربت حیدریه

the aim of this study is to develop a model to provide projections of supply of major crops in target year 2025 in iran. to this end, a model was constructed using positive mathematical programming (pmp) approach. the model takes into account production factors constraints in different provinces in the base year as well as in the target year, and provides forecasts of potential supply of major ...

2010
Jacob van Etten Robert J. Hijmans

BACKGROUND The study of the prehistoric origins and dispersal routes of domesticated plants is often based on the analysis of either archaeobotanical or genetic data. As more data become available, spatially explicit models of crop dispersal can be used to combine different types of evidence. METHODOLOGY/PRINCIPAL FINDINGS We present a model in which a crop disperses through a landscape that ...

Journal: :Journal of experimental botany 2015
R P Rötter F Tao J G Höhn T Palosuo

A major challenge of the 21st century is to achieve food supply security under a changing climate and roughly a doubling in food demand by 2050 compared to present, the majority of which needs to be met by the cereals wheat, rice, maize, and barley. Future harvests are expected to be especially threatened through increased frequency and severity of extreme events, such as heat waves and drought...

Journal: :Environmental science & technology 2012
Peter Fantke Peter Wieland Ronnie Juraske Gavin Shaddick Eva Sevigné Itoiz Rainer Friedrich Olivier Jolliet

An approach for estimating human exposure to pesticides via consumption of six important food crops is presented that can be used to extend multimedia models applied in health risk and life cycle impact assessment. We first assessed the variation of model output (pesticide residues per kg applied) as a function of model input variables (substance, crop, and environmental properties) including t...

2016
Supratim Basu Venkategowda Ramegowda Anuj Kumar Andy Pereira

Plants in their natural habitats adapt to drought stress in the environment through a variety of mechanisms, ranging from transient responses to low soil moisture to major survival mechanisms of escape by early flowering in absence of seasonal rainfall. However, crop plants selected by humans to yield products such as grain, vegetable, or fruit in favorable environments with high inputs of wate...

2011
Sijie Wu Jianxi Huang Xingquan Liu Jinlong Fan Guannan Ma Jinqiu Zou

Regional crop yield prediction is a vital component of national food security assessment. Data assimilation method which combines crop growth model and remotely sensed data has been proven the most potential method in regional crop production estimation. This paper takes Hengshui district as study area, WOFOST as crop model, MODIS-LAI as observation data to test and verify the efficiency of EnK...

Journal: :Molecular plant pathology 2006
David O Niño-Liu Pamela C Ronald Adam J Bogdanove

SUMMARY Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola cause bacterial blight and bacterial leaf streak of rice (Oryza sativa), which constrain production of this staple crop in much of Asia and parts of Africa. Tremendous progress has been made in characterizing the diseases and breeding for resistance. X. oryzae pv. oryzae causes bacterial blight by invading the vascular t...

2006
Nantachai Kantanantha Nicoleta Serban Paul Griffin

Crop decision planning is an important part of effective farm management. Because of the many uncertain factors such as weather variations, technology advances, and crop yields and prices, all of which prove to change considerably, decision planning can be very complex. The focus of this paper is to develop accurate yield and price forecasting models to aid in decision planning. For yield forec...

2005
Paul C. Doraiswamy Sophie Moulin Paul W. Cook Alan Stern

Monitoring crop condition and production estimates at the state and county level is of great interest to the U.S. Department of Agriculture. The National Agricultural Statistical Service (NASS) of the U.S. Department of Agriculture conducts field interviews with sampled farm operators and obtains crop cuttings to make crop yield estimates at regional and state levels. NASS needs supplemental sp...

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