UIsing phosphorus in horticultural crops has been researched for a long time, almost since it was discovered in 1669 by Hennig Brand in Germany. Recent advances in phosphorus application, involving using precision placement of coated fertilizers and by inoculating crops with mycorrhizae, have provided-more efficient uptake and increase in plant yields. By reviewing the key discoveries and current work going on, we can better design our future projects as nutrition scientists. While this approach will not encompass all horticultural crops, results with vegetables and ornamentals should provide concepts for work with other commodities.
Horticulturists need to stay abreast of the rapidly changing technology for disseminating research and teaching information. By connecting to the Internet and using the various tools available, horticulturists can gather information needed to communicate with colleagues and other clientele as a means of highlighting our science. The use of network software, such as FTP (file transfer protocol), Gopher, Veronica, Archie, Jughead, WAIS (wide area information servers), Mosaic, Netscape, Telnet, IRC (Internet relay chat), and WWW (World Wide Web) is essential in navigating the super information highway. This largely academically based network will evolve based on needs and politics in the years to come.
The use of the Internet and specifically the World Wide Web has grown rapidly in the last 2 years. There are now >60 million web pages on the Internet, each containing information on various subjects and many having very useful information. The text is viewed with a web browser, using a hypertext markup language, enabling formatting similar to word processing. Graphics, sounds, and video are accessed from hot links in the text. While commercial users are struggling with marketing strategies, the web will continue to evolve. We as educators will continue to dominate the rapid growth due to increased needs to reach more students with fewer resources. By adding course materials on-line, instructors can enhance the learning process. Interactive computer teaching modules will give students more one-on-one experience at their own pace. Then, by adding e-mail connectivity to instructors, students can have daily or even hourly access for questions. By careful Web page design, we can hold the interest of our students and disseminate more information than ever before.
Since DRIS calculations prove to be tedious for most researchers, a computer pro am was written to use test data from foliar analyses to compile DRIS norms for a population and using these norms, calculate the indices for each of 14 elements.
The data to be tested is first put into a record base format and stored as an ASCII file. When DRISCALC is run on IBM compatible microcomputers, this data is separated into two subpopulations based on the mean yield for the main population. The next procedure calculates the mean, the standard deviation (from the mean), and the variance for each subpopulation as well as the variance ratio (low yield/high yield) and the CV.
The F test for variance and the student's t test selects the norms (high population mean and CV'S). After construction of this temporary database, and unknown sample is entered into the program for testing. DRIS indices are calculated and several statistical options can be selected b the user. Hidden deficiencies can be found by the researcher or DRIS principles can be taught to students.
The Packhard treatment included Packhard® Caenise at 3 qt/A rate applied at four equally spaced intervals beginning on 1 May 1996 and continuing until harvest on 29 July 1996. After harvest, treated and nontreated peaches were stored at 1°C, 95% RH. For up to 42 days, after which they were allowed to ripen for 6 days at 18°C. Fruit from 5-day storage intervals and 2-day ripening intervals were then evaluated for firmness, color, brown rot lesions, soluble solids, titratable acidity, starch, pectin, total Ca, and fruit epidermis thickness. Packhard protected the fruit in cold storage for 42 days from brown rot compared to the controls, which began to breakdown in 26 days. The ripening studies have given mixed results suggesting that there is no difference in the degree of brown rot contamination between Packhard-treated fruit and control fruit after removal from storage. Fruit firmness was increased by Packhard in the majority of the storage periods. Sucrose content seemed to have been reduced in the Packhard-treated fruit compared to the controls, possibly due to increased respiration. The Packhard-treated fruit retained more moisture than the control fruit,, which indicates that Ca2+ from Packhard may have increased the integrity of the plasma membranes of treated fruit. In general, the Packhard-treated fruit held up much better in cold storage than the control fruit but was not different in brown rot infection during ripening. Packhard increased fruit firmness and allowed the fruit to retain more moisture than the control fruit. Sucrose content decreased in Packhard-treated fruit compared to the controls.