Download or read book Alfalfa Seed Production as Affected by Revolving Cylinder Pressure Tripping and Cross pollination of Alfalfa by Honey Bees written by Carl Edward Ekstrom and published by . This book was released on 1952 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alfalfa Seed Production written by Charles Vancouver Piper and published by . This book was released on 1914 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Honey Bees in Alfalfa Seed Production written by George Haymaker Vansell and published by . This book was released on 1951 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Some Factors that Affect Pollination and Seed Formation in Alfalfa Medicago Sativa L written by Norman Richard Bradner and published by . This book was released on 1964 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this study were (a) to measure the amount of cross-pollination caused by three bee species at 10, 20 and 40 rods distance from a foreign pollen source, (b) to measure the effects of bee species, planting pattern and season on broad sense heritability estimates for seed yield in alfalfa, (c) to determine the incidence of selfing caused by the bees, (d) to investigate the usefulness of bees as a breeding tool in alfalfa and (e) to determine which of the three planting patterns used in this investigation is the best in effecting the maximum amount of cross-pollination. Three bee species, the honey bee, Apis mellifera L.; the leaf-cutter bee, Megachile rotundata F. and the alkali bee, Nomia melanderi Ckll. were chosen for this investigation because of their importance as pollinators in alfalfa. Studies under conditions of good isolation for bee species and competitive bloom were necessary to obtain reliable results. In the center of a three mile square isolated area, seven plots of recessive white-flowered clonally established plants were planted 10, 20, 40, 80, 160, 240 and 320 rods north of a colored-flowered population, and seven plots were planted at the same distance east of the colored-flowered population. Seven planting patterns were used in the east series. Three of these were utilized by the bees described. The number of florets tripped, pods developed and seeds developed in each pod were recorded for each raceme visited by pollen collecting bees. Seed samples from the white-flowered clones were grown in a greenhouse to ascertain whether the seed resulted from cross- or self-pollination. A record of flower color in 1963 demonstrated that at 10, 20 and 40 rods from a contaminant source honey bees caused 15.7, 11.2 and 5.8 percent cross-pollination; leaf-cutter bees caused 13.1, 4.8 and 8.1 percent cross-pollination while endemic pollinators caused 42.9, 30.9 and 10.0 percent cross-pollination in 1962. An important fact in this regard was that endemic pollinators caused 6.52 percent cross-pollination at a distance of a mile. Bee species, planting pattern and season caused large fluctuations in broad sense heritability estimates for seed yield in alfalfa. The ratio environmental variance to phenotypic variance gave a good indication which environmental factor caused the most fluctuation in the estimate. When endemic pollinators were used 94.7, 88.3, 36.3 and 23.1 percent selfed seeds were recorded as occurring in pods with one, two, three and four or more seeds per pod. One seven seeded pod was recorded as possessing three selfed seeds. Data from leaf-cutter bees showed that all of the pod types had over 67 percent selfed seeds. Distance from the contaminant source affected the percentage selfed seeds. At 40 rods only the four or more seeded pods contained any crossed seeds (20 percent) Leaf-cutter bees trip 27-50 percent more florets per raceme and cause less cross-pollination at 10, 20 and 40 rods than honey bees. Honey bees cause approximately the same amount of cross-pollination at 10 and 20 rods while the value obtained at 20 rods for the leaf-cutter bee was close to one-third of the value at 10 rods. Leaf-cutter bees also showed less preference between colored- and white-flowered alfalfa flowers. Of several planting patterns considered, maximum cross-pollination was obtained in a plot planted with alternating rows of alfalfa.

Download or read book Bloom Dynamics in Alfalfa Medicago Sativa L written by David E. Chaney and published by . This book was released on 1985 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pollinator mediated Gene Flow in and Among Fields of Alfalfa Produced for Seed written by Natalie Kira Boyle and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We evaluated the impact of migratory beekeeping practices on transgenic pollen flow between spatially isolated alfalfa fields by permitting honey bees, Apis mellifera, to openly forage upon transgenic alfalfa blossoms, and transporting them 112 km to forage on caged conventional alfalfa following either 8 or 32 hours of isolation from the transgenic source. Cross-pollination between transgenic and conventional alfalfa was nearly eliminated (0.00008%) following eight hours of isolation from the transgenic source.

Download or read book Alfalfa Seed Production written by J. M. Westgate and published by . This book was released on 1912 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gene Flow in Alfalfa written by Allen Emile Van Deynze and published by . This book was released on 2008 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Although there have been instances in which low-level presence of regulated materials has resulted in market disruptions (e.g., Starlink corn, LL601 and LL604 rice), there is no evidence of significant market disruption associated with the commercialization of deregulated biotech traits in the United States. Concurrent with increased U.S. farmer adoption of biotech traits in corn, soybean, and cotton there have been increases in U.S. grain/fiber export (USDA-FAS 2007) and organic production (USDA-NASS 2007a, b, c). Although only 3 to 5% of the U.S. alfalfa hay production is sold to GE-sensitive markets (Putnam 2006), production for these markets has significant economic importance in specific regions of the United States. Approximately 33% of U.S. alfalfa seed production is exported, primarily to GE-sensitive markets. A thorough understanding of gene flow in alfalfa is critical to establishing stewardship programs that enable coexistence between alfalfa growers producing GE alfalfa hay or seed and growers producing these products for GE-sensitive markets. Understanding the relative importance of gene flow between and within feral plants, hay, and seed production fields helps to identify key biological, agricultural, and environmental barriers to gene flow and to formulate logical mitigation strategies for managing the AP of GE traits in non-GE alfalfa seed and hay. Synchrony in flowering, presence of pollinators, isolation distance, and relative abundance of pollen between pollen source and pollen recipient plants are typical biological barriers, most of which are amenable to management in hay and/or seed production systems. In general, it seems that NAFA Best Management Practices in hay and certified alfalfa seed production, coupled with the pollinator-specific isolation guidelines outlined in the NAFA Best Management Practices document, are adequate for managing AP to tolerance levels appropriate for most markets. These types of management practices are employed successfully by producers of certified seed in most crops, including alfalfa, to ensure genetic purity of seed stocks. Increased isolation distances in seed production--including production in non-GE seed production zones--use of border areas, crop rotation, use of certified seed, careful selection of the introduced pollinator, and routine elimination of neighboring feral alfalfa plants are tools that can be applied to decrease further the risk of gene flow in the production of seed for GE-sensitive markets."--Summary.

Download or read book Quantitative Inheritance of Ease of Floret Tripping and Effect of Ease of Floret Tripping on Outcrossing Rate and Pollen Flow in Alfalfa written by Eric Enzio Knapp and published by . This book was released on 1992 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Movement of Pollinators and Their Impact on Selfing and Gene Flow in Alfalfa written by Emmanuel Santa-Martinez and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insect pollinators are important for the seed production of vegetables and fruits and for some forage and oil crops. Little is known about their impact on selfing, gene flow and plant mating systems. Both selfing and gene flow in agriculture are affected by how pollinators forage on plants. How pollen is deposited from flower to flower throughout consecutive visits can vary among pollinators. Pollinators can affect the proportion of seeds that results from self-fertilization. Also, pollinators can mediate gene flow via pollen and therefore help move genes among fields. Alfalfa represents a good model system to contrast the impact of distinct pollinators on selfing and gene flow. This thesis examines the foraging behavior of the European honey bee, the common eastern bumble bee and the alfalfa leafcutting bee on alfalfa plants and determine their impact on selfing rate and potential for gene flow. Selfing rate estimates were higher on plants visited by leafcutting bees and honey bees relative to bumble bees. Differences among bee species on the number of sequentially visited flowers, tripping rates and their ability to remove or deposit more pollen grains during a visit to a flower can explain the differences observed in selfing rates. We also quantified the impact of these pollinators on the reproductive success via female and male functions in alfalfa. Bee species affected plant reproductive success via both female and male functions. Plants visited by bumble bees had greater female and male reproductive success relative to honey bees and leafcutting bees. Differences among bee species in their impact on plant reproductive success were linked to differences in foraging behavior. Lastly, we compared pollen deposition curves for two bee species and their potential for transgene escape. Leafcutting bees exhibited steeper pollen deposition curves, hence shorter tails relative to bumble bees. This work improves our understanding of how distinct pollinators affect selfing rate and gene flow and therefore, how pollinators affect plant mating systems and ultimately the genetic structure of plant populations. This research contributes to the development of planting strategies to help reduce transgene escape and to promote the effective coexistence across different markets.

Download or read book Factors that Affect Alfalfa Seed Yields written by Philo Kneeland Blinn and published by . This book was released on 1920 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Survey of Alfalfa Pollinators and Polination in the San Joaquin Valley of California with Emphasis on Establishment of the Alkali Bee written by Philip F. Torchio and published by . This book was released on 1966 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study involves the establishment, management, and behavioral observations of Nomia melanderi Cockerell and Megachile rotundata (Fabricius) in California, a survey of native bees within western Fresno County, a determination of selfing and/or parthenocarpy in two fields of alfalfa, and observations on the honeybee as an alfalfa pollinator. The alkali bee is characterized. It is an endemic species limited to western North America. Eight artificial alkali bee nesting sites were constructed during the establishment program. Details of materials used during construction and their importance are discussed. Alkali bee cores used for introduction into California were procured in eastern Oregon and western Idaho, trucked to California, and planted in artificial sites. The heavy usage of insecticides in the area of study proved to be the greatest problem in the survival of the alkali bee. Observed toxicities of Dimethoate, Sevin, Malathion, Systex-Toxaphene, Toxaphene, DDT, Phosdrin, Dibrom, TEPP, Dylox, and Kelthane on the alkali bee were compared. The occurrence of multiple generations of the alkali bee in California is reported. Explanation of this behavior is based upon high soil temperatures (82° F. and above) during the nesting season. The importance of multiple generations is discussed. Biologies and importance of alkali bee parasites in California are described. Procedures for the control of some species are outlined. Methods of constructing trap nests for Megachile rotundata and their distribution throughout the San Joaquin Valley are described. Collections of these trap nests were then made and placed in one field so that readings on frequency of tripping, number of pollen loads required to provision cells, and time required to collect leafcuttings could be made. Observations on mating positions were described. The smallest males and largest females were reproductively isolated because of size difference. Parasites (Melittobia chalybii Ashmead and Monodontomeris montivagus Ashmead) and competitors (Ashmediella aridula Cockerell and Hylaeus grossicornis (Swenk and Cockerell) of Megachile rotundata are discussed. Melittobia chalybii Ashmead, a chalcid wasp, is potentially the most serious parasite and could decide the success or failure of M. rotundata in California. A survey of native bees was made in the area of study. Eight native species were found and their biologies described. Preferred pollen host plants were determined. Reasons why native bee biologies should be studied and understood are given. Two cages, one placed in a Tan Verde seed field and the second in a Ranger field, were used to calculate amount of seed produced from pathways other than by cross-pollination. Comparison of seed harvested from caged plots and field plots indicated that seed produced by non cross-pollination mechanisms could account for the average seed yields in California during recent years. Germination tests indicated, however, that seed produced by mechanisms other than cross-pollination is inferior. Only seven honey bees were observed collecting alfalfa pollen throughout the period of study. Consequently, no valid comparison between its pollinating capacity and that of wild bees could be made.

Download or read book Honey Bees in Alfalfa Seed Production written by University of Arizona. Agricultural Experiment Station and published by . This book was released on 1970 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alfalfa Seed Production written by Charles Vancouver Piper and published by Palala Press. This book was released on 2015-09-15 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Download or read book Growing Alfalfa for Seed written by Marion Walter Pedersen and published by . This book was released on 1955 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alfalfa Seed Production Studies written by Marion Walter Pedersen and published by . This book was released on 1962 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings written by and published by . This book was released on 1975 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: