Author: Joseph Thomas Gaspard
Publisher:
ISBN:
Category : Hybrid corn
Languages : en
Pages : 158

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 944

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Author: Zewudu Oumer
Publisher:
ISBN:
Category :
Languages : en
Pages : 132

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Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 886

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Author:
Publisher:
ISBN:
Category : Electronic journals
Languages : en
Pages : 224

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Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 1732

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Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 748

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Author: Krista J. Ubbenga
Publisher:
ISBN:
Category :
Languages : en
Pages :

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In 1996, genetically modified corn was commercially available for the first time. Since then, seed technology companies have introduced new genetically modified hybrids, including 0́5stacked trait hybrids0́6 containing multiple traits. Adoption rates of the genetically modified seed increased for several years and the technology is now widely accepted in the United States. Willingness to adopt a new technology is based on the belief that it is an improvement over current practices. Seemingly, a triple-stack corn hybrid (a hybrid containing three genes) should provide a higher net return than a hybrid with fewer genetic traits. Dramatic farmer adoption rates of triple-stack corn hybrids could suggest that farmers believe that the added traits will improve hybrid performance. On the other hand, farmers must also choose seed from the selection available, consisting mostly of hybrids with a triple-stack trait package. Previous studies comparing transgenic yields to non-transgenic yield have mixed results. However, the literature reviewed suggests that farmers believe that there is a yield advantage associated with triple-stack corn hybrids. Therefore, the hypothesis is developed that farmers0́8 subjective estimates of triple-stack corn yields will be above the yields found in the objective data. Three goals are set to test this hypothesis: 1) determine the effect that traits in hybrids have on corn yields, specifically the effect of triple-stack traits on corn yields; 2) determine what farmer perceptions of triple-stack hybrid yields are; and 3) compare the triple-stack objective yield data to farmer perceptions. The objective data are from the University of Illinois corn hybrid test trials from 2004-2008. Hybrids are assessed based on the traits present and regression models are used to test for statistical differences in yields between hybrids with varying traits. Personal interviews conducted with eight farmers located across Illinois in August, 2009, and a survey distributed to 65 Farm Business Farm Management Association cooperators in September, 2009, are used as proxies for farmer perception; the results from both are used as subjective data in the study. The objective yield data shows that the traits for corn borer resistance and root worm resistance both significantly increase yield by approximately 2 and 4 bushels per acre, respectively. A trait for herbicide tolerance was not found to make a significant difference in yield. Triple-stack hybrids, containing all three traits, have a yield advantage of 6-7 bushels per acre. In the interviews, farmers indicated a value in triple-stack corn hybrids, but much of that value is due to advantages other than yield. Farmers who pinpointed a range for triple-stack yield advantage over refuge hybrids, selected ranges beginning at 7 bushels per acre and going up to 15 bushels per acre. Based on weighted averages of the responses from farmers who selected a specific range in the survey, the farmers who plant triple-stack hybrids believe triple-stack yields are 9.45 bushels per acre higher than refuge and the farmers who do not plant triple-stack hybrids believe triple-stack hybrids yield 5.87 bushels per acre higher than refuge. A conclusion is reached that farmers0́8 yield assessments are fairly accurate. Farmers that plant triple-stack hybrids perceive a triple-stack yield advantage that is slightly higher than the value found in the objective data, although some did not provide a specific range. Interestingly, 23% of farmers planting triple-stack hybrids believe triple-stack and refuge yields are the same.

Author: Mohammad Hassan Roozitalab
Publisher: Springer
ISBN: 3319690485
Category : Nature
Languages : en
Pages : 257

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This unique book addresses Iran’s extremely rich soil diversity and resources, which have developed under various climatic conditions ranging from dry to humid conditions. Featuring contributions by a group of respected experts on Iranian soils and agriculture, it provides comprehensive information on the management approaches needed for sustainable soil utilization and conservation under such conditions, and the attendant challenges. As such, it offers a valuable resource for anyone interested in soils and agriculture in Iran, but also in other Middle East and North African countries with similar climatic conditions. The book contains 14 chapters which illustrate the long history of indigenous knowledge and soil research, climate, geology and geomorphology, vegetation cover, soil forming factors and processes, major soils, properties and their classification. Furthermore, it presents past climate change and paleosols, agroecological zones, soil fertility, soil biology and biotechnology, human induced land degradation and “soil management in space and time”. In the end, major challenges facing the soil resources of the country are defined and recommendations are made to face the future challenges.

Author: C. Phillip Baumel
Publisher:
ISBN:
Category : Agricultural ecology
Languages : en
Pages : 472

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