Search Results

You are looking at 1 - 10 of 395 items for :

  • "plant nutrition" x
Clear All
Free access

Donald N. Maynard

Handbook of Plant Nutrition. 2007. Allen V. Barker and David J. Pilbeam (eds.). CRC Press, 600 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487. 613 p., $139.95 hardcover. ISBN 0-8247-5904-4. For almost half a century Chapman

Full access

Cindy L. McKenzie and Joseph P. Albano

combinations have been shown to reduce the severity of the disorder by reducing sweetpotato whitefly populations ( Powell and Stofella, 1998 ; Schuster, 2002 ; Schuster et al., 1989a , 1989b ) Plant nutrition may also play a key role in the tomato ripening

Free access

Larry S. Kennedy, William B. Beavers and Carl E. Sams

A common problem of researchers concerned with micronutrient plant nutrition is the development of a reliable and affordable experimental system. If nutrient distribution is uneven or subject to outside contamination, then the time and resources dedicated to a project will have been wasted. We have devised a dependable and cost effective nutrient distribution system which has many practical applications. This design is relatively maintenance free, easily adaptable to existing greenhouse conditions and limits the possibility of outside contamination. Using perlite as the rooting medium, our system is constructed of easily obtainable hardware and mechanical components. The total material cost of our system, which included three nutrient treatments, was approximately $800. This resulted in a conservative estimate of $12.50 per plant in our particular study. However, the cost of a larger experiment would be reduced considerably since additional replications could be added at approximately $2.00 each. The experimental set-up is described along with the initial cost analysis.

Free access

Rufus L. Chaney

Depending on the materials used to produce a compost, it will contain lower or higher levels of nutrients and metals. If composts have been appropriately matured, nutrients are in plant-available forms for crop production, and the compost pH will be near neutral. After 25 years of research and development of regulations and advice for biosolids and compost utilization, pretreatment of industrial wastes allows biosolids composts, and composts prepared from biosolids mixed with municipal solid wastes or yard debris to contain levels of microelements needed for plant nutrition but not high levels that could cause phytotoxicity. Composts can supply N, P, K, Ca, Mg, Fe, Zn, Cu, Mn, B, Mo, and Se required by plants or animals. When used in potting media, supplemental N fertilization is usually required, depending on crop requirements. Use of compost can replace other forms of microelements used as fertilizers in media or fields. Detailed evaluation of potential food chain transfer of Cd, Pb, and other elements in composts clearly shows that consumption of 60% of garden foods produced on pH 5.5 soils with 1000 t compost/ha would not comprise risk over a lifetime of consumption, nor would ingesting the composts at 200 mg/day for 5 years. Potentially toxic organic compounds are either destroyed during composting, or bound very strongly by the compost so that plant uptake is trivial. Compost use can be a safe and wise choice for both home and commercial use to replace peat or uncomposted manures, etc. Many states have developed regulatory controls to assure that pathogenic organisms are killed during composting, and that product quality standards are attained that allow marketing for general use in the community.

Restricted access

Joseph P. Albano, James Altland, Donald J. Merhaut, Sandra B. Wilson and P. Chris Wilson

]. To investigate this problem, we conducted a long-term (52-week) study to assess irrigation water chemistry, the effects of alkalinity level/irrigation water acidification on substrate chemistry and on plant nutrition and growth for thyrallis grown

Full access

Ellen T. Paparozzi and Kimberly A. Williams

Chat rooms and their use in everyday life are becoming increasingly common, and the technology may be a useful tool to link students with experts of a given subject material and each other. In our shared course Plant Nutrition and Nutrient Management, we experimented with using a chat room to link students with experts in the field of plant nutrition. Our main goal was to enhance the learning experience of the students by providing them with access to national and international plant nutrition researchers. Web CT was used to create and conduct the chat rooms and a chat etiquette evolved to prevent crosstalk and control the flow of the discussions. Positive outcomes of the chat room use included exposure of students to the technology and beneficial interaction between students and experts. Negative aspects of chat room use included the time involved to coordinate the overall effort and train experts to use the technology; the slow pace of some chats; effective grading; and the superficial coverage of some topics. We are developing modifications for future sessions to allow subjects to be explored in more depth and to improve networking between students and experts.

Free access

Kim Williams, Ellen T. Paparozzi and Jerry Maranville

As universities are required to “right-size,” faculty resources of time and expertise are strained as the institution must cater to undergraduate students while providing a complete graduate curriculum. Thus, many institutions are offering more team taught courses. For a new upper-level undergraduate and lower-level graduate course offering in Plant Nutrition and Nutrient Management, the team consists of faculty from two institutions who each bring different expertise into the classroom. The course utilized weekly chat room discussions to bring students into contact with experts from around the United States and the world. Two-way compressed video was used to allow for synchronous lecture delivery and discussion across sites. A Web site was created to facilitate student interaction and provide chat room access. Multiple student evaluations were conducted to separate learning objectives with the effectiveness of using technology. A flow-chart will be presented which details the steps and problems/accomplishments encountered in successfully delivering this course via distance technologies, including: funding procurement, determining technological compatibility across institutions, delineation of course content, Web page development, and course evaluations.

Free access

Xinhua Yin, Janet Turner, Clark Seavert, Roberto Nunez-Elisea and Helen Cahn

Theinfluences of a synthetic fabric cover in the row area of sweet cherry trees on soil fertility and plant nutrition are largely unknown. A field trial has been conducted on young `Regina' sweet cherry on a sandy loam soil at the Mid-Columbia Agricultural Research and Extension Center, Hood River, Ore., since 2001. The difference in soil NO - 3, P, K, Ca, Mg, S, B, Zn, Mn, Cu, pH, or organic matter was nonsignificant between the covered and non-covered treatments in any year. Leaf N content was 11% to 16% greater with the covered treatment compared with the non-covered treatment in 2002 and 2003, but leaf N was similar for the two treatments in 2001. Leaf P content was similar for the two treatments in 2001, but was about 36% less with the covered treatment than the non-covered treatment in 2002 and 2003. Leaf Ca content was decreased by 11% to 17% due to a synthetic fabric cover in 2002 and 2003. Leaf Mg content was 13% to 24% less with the covered treatment than the non-covered treatment in 2002 and 2003. However, the decreased leaf P, Ca, and Mg contents with the covered trees were due to the dilute effects of increased tree growth. The effects of a fabric cover on leaf K, S, B, Zn, Mn, and Cu contents were primarily nonsignificant. Our results suggest that although nutrient availability in the soil is not reduced by a wide synthetic fabric cover, higher rates of fertilizers may be needed for the covered sweet cherry trees due to the elevated tree growth and fruit production from a long-term perspective.

Free access

Arnon Dag, Ran Erel, Alon Ben-Gal, Isaac Zipori and Uri Yermiyahu

. Despite the crop's importance, no previous studies have been performed on the effect of olive stock plant nutritional status on propagation rates. In vitro rooting ability depends on many endogenous and exogenous factors such as genetic background