[PDF] The Effect Of Defoliation And Nitrogen Application On The Seed Yield Of Linn Perennial Ryegrass Lolium Perenne L And Merion Kentucky Bluegrass Poa Pratensis L eBook

Author : Matthew William Mulanax
Publisher :
Page : 118 pages
File Size : 32,92 MB
Release : 1971
Category : Grasses
ISBN :

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The effect of clipping and supplemental nitrogen application on seed production of Linn perennial ryegrass and Merion Kentucky bluegrass was studied. Clipping and nitrogen treatments did not significantly affect the seed yield of Linn perennial ryegrass during the 1967 growing season. The seed yield of Merion Kentucky bluegrass was significantly increased by a combined winter-spring clipping regime when compared with the unclipped control. Application of 136 pounds of nitrogen in two equal spring applications significantly reduced the seed yield of Merion Kentucky bluegrass. Spring clipping tended to reduce the number of fertile tillers per unit area for both species. Supplemental nitrogen generally increased the number of fertile tillers per unit area for Linn perennial ryegrass. Application of 30 pounds of additional nitrogen delayed the period of head emergence for Linn perennial ryegrass. The time of pollen shed of Merion Kentucky bluegrass was delayed by all clipping regimes.

Author : J. Kevin Turner
Publisher :
Page : 234 pages
File Size : 20,76 MB
Release : 1989
Category : Lolium perenne
ISBN :

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Rapid tiller and root production can improve seedling survival and benefit stand establishment of perennial ryegrass (Lolium perenne L.) in commercial seed fields. Environmental conditions after establishment and inherent morphological factors combine to reduce the commercially harvested yield below the theoretical potential yield. These studies were conducted to determine if the growth retardant paclobutrazol and KCl could favor maximum seed yields of the cultivar Ovation under field conditions. In addition, effects of paclobutrazol and P on seedling development were examined in a growth chamber. Paclobutrazol increased seed yields in both first- and second-year stands in each of three climatically different years. Yield increases were primarily due to increased numbers of spikes per unit area during the wet year of 1984 and to increaseed numbers of seeds per spike in the dry years of 1985 and 1986. Seeds per unit area and harvest indices increased and thousand seed weights (TSW) decreased in all three years. KC1 applications were intended to offset the anticipated paclobutrazol-induced TSW reductions. Positive fertilizer effects were due to Cl rather than K. Chloride fertilizer salts tended to increase seed yields, seeds per unit area, and TSW in 1984 and significantly increased yields, seeds per unit area and TSW in 1985. Severe drought masked possible Cl effects in 1986. The effects of Cl were thought to be due to its influence on N form taken up by the plant. Paclobutrazol reduced shoot and root weights but did not affect the shoot:root ratios of 90-day old growth chamber grown seedlings. Plant growth in height was reduced within two days of application, which suggested the dependence of seedlings on continual gibberellin production. Phosphorus increased the shoot weights of 90-day old seedlings, but did not affect root weights. Significant interactions were observed on the numbers of leaves and tillers per plant within 9 and 16 days of treatment applications, respectively. Paclobutrazol increased numbers of leaves and tillers per plant, but only at the high P rate. The reduced root growth caused by paclobutrazol and the immobile nature of P in the soil may account for the interaction effects.

Author : Josef Palti
Publisher : Springer Science & Business Media
Page : 259 pages
File Size : 44,47 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 3642682669

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The development of a crop, and therefore its health, is always the result of interplay between biological and environmental factors, as influenced by human agency. In other words, crop health is a highly complex affair. This book is concerned with only one group of agents affecting crop health, the pathogens, and not with animal pests or direct effects of physiological or weather factors. Even within this one group, however, the interaction of causal agents with environmental and biotic factors is highly complex. No less complex is the effect of cultural practices on the crop and its health. There is probably no major practice that does not affect diverse facets of crop growth, which in turn affects crop/pathogen relationships. Thus tillage se quentially affects depth and rate of root development, hence nutrient uptake, hence general plant size and habit as well as crop climate and crop susceptibility. Irri gation affects all these parameters, and facilitates crop growth under diverse macro climatic conditions, with all the ensuing implications for disease development. In this book an attempt is made to superimpose one set of complexities, the cul tural practices, on another such set, crop health. This may seem overambitious, not to say foolhardy, unless we remember that it has been done by farmers, consciously or unconsciously, ever since the beginnings of agriculture. We are here chiefly try ing to rationalize traditional practices, review modern research on the development of further practices, and assess the place of the latter in integrated disease control.

Author : National Research Council
Publisher : National Academies Press
Page : 484 pages
File Size : 42,92 MB
Release : 1986-02-01
Category : Technology & Engineering
ISBN : 0309036275

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Based on a symposium sponsored by the Board on Agriculture, this comprehensive book explores the problem of pesticide resistance; suggests new approaches to monitor, control, or prevent resistance; and identifies the changes in public policy necessary to protect crops and human health from the ravages of pests. The volume synthesizes the most recent information from a wide range of disciplines, including entomology, genetics, plant pathology, biochemistry, economics, and public policy. It also suggests research avenues that would indicate how to counter future problems. A glossary provides the reader with additional guidance.

Author : Kan Wang
Publisher : Humana Press
Page : 512 pages
File Size : 27,89 MB
Release : 2010-12-09
Category : Science
ISBN : 9781617378034

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Agrobacterium tumefaciens is a soil bacterium that for more than a century has been known as a pathogen causing the plant crown gall disease. Unlike many other pathogens, Agrobacterium has the ability to deliver DNA to plant cells and permanently alter the plant genome. The discovery of this unique feature 30 years ago has provided plant scientists with a powerful tool to genetically transform plants for both basic research purposes and for agric- tural development. Compared to physical transformation methods such as particle bomba- ment or electroporation, Agrobacterium-mediated DNA delivery has a number of advantages. One of the features is its propensity to generate single or a low copy number of integrated transgenes with defined ends. Integration of a single transgene copy into the plant genome is less likely to trigger “gene silencing” often associated with multiple gene insertions. When the first edition of Agrobacterium Protocols was published in 1995, only a handful of plants could be routinely transformed using Agrobacterium. Ag- bacterium-mediated transformation is now commonly used to introduce DNA into many plant species, including monocotyledon crop species that were previously considered non-hosts for Agrobacterium. Most remarkable are recent devel- ments indicating that Agrobacterium can also be used to deliver DNA to non-plant species including bacteria, fungi, and even mammalian cells.

Author : Mohammad Pessarakli
Publisher : CRC Press
Page : 730 pages
File Size : 40,96 MB
Release : 2007-10-09
Category : Science
ISBN : 1420006487

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A multibillion dollar industry that has tripled in the last ten years, turfgrass management plays an important role in landscaping, golf courses, and other sports surfaces. Proper management and cultural practices are crucial for the performance of these versatile grasses, creating a demand among scientists, researchers, and industry professionals

Author : Robert E. Wilkinson
Publisher : CRC Press
Page : 480 pages
File Size : 13,93 MB
Release : 2000-07-12
Category : Science
ISBN : 0824746562

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This book presents comprehensive coverage of differentiated plant responses to changing environments. It focuses on how multiple and combined stress factors influence plant survival. It examines the latest data on the capacity of roots to alter growth patterns due to disturbances in physical and/or chemical soil constraints, water supply, and other traumas. It contains over 85% new and updated material with more than 1500 new citations, tables, drawings, and photographs.

Author : David Watson
Publisher : Elsevier
Page : 659 pages
File Size : 19,3 MB
Release : 2012-12-02
Category : Technology & Engineering
ISBN : 0323143806

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Pesticide Management and Insecticide Resistance explores the problem of insect resistance to pesticides and reviews various approaches to pesticide management and safety. It looks at the environmental hazards of pesticide residues and their regulation, along with application techniques aimed at maximum efficiency against the pest and minimum waste to pollution, safety considerations in the development of pest control programs, and pesticide monitoring. Divided into eight parts encompassing 49 chapters, this volume begins with an overview of the global pesticide industry and the costs of commercializing pesticides relative to their profit potential. It then introduces the reader to the release of fluorohydrocarbon propellants in pesticidal aerosols and their hazards to the ozone layer, management of pests in urban environments, international plant protection, the current status of DDT, the importance of training pest-control personnel, and procedures of forest spraying. Other chapters focus on pesticide management safety from a medical perspective; pesticide safety as it relates to the manufacturing, warehousing, and distribution of pesticides; importance of pesticide application equipment and related field practices in developing countries; and the importance of pesticides in successful pest management programs. This book is a valuable resource for scientists, students, researchers, and policymakers who want to ensure the safety of consumers, applicators, and harvesters when using pesticides.