The experiment which has just concluded (currently being conducted) in the University of Arizona’s CEAC Crop Production Laboratory (Teaching Greenhouse) and carried out by students of the PLS 217 and 394 classes, is the second in a series to evaluate growth and tomato yield of grafted versus non-grafted plants. The beef type tomato variety, Rapsodie (chosen because of its excellent performance in previous trials at the UA/CEAC in Tucson), was (is being) grown under five (three) treatments: (1) from seed, (2) grafted to a Maxi-Fort root stock and trained to a single stem, (and) (3) grafted to Maxi-Fort and trained to two stems, 4) grafted back to a Rapsodie root stock and trained to a singe stem and 5) Rapsodie from seed but trained to two stems. Grafting has been used in the past primarily to confer disease resistance to plants growing in soil by combining a good producing scion (aerial portion of plant) to a disease resistant root (root stock). Recently, however, greenhouse tomato growers have been using grafting to combine a variety that produces a large number of good quality fruit (scion) with a vigorous rootstock that transports water and nutrients very well. To our knowledge, these are (this is) the first such side-by-side comparisons of these (3) treatments and will hopefully yield interesting data relevant to the industry.
Cooperators: Dr. Merle Jensen, Dr. Roger Huber, Dr. Mary Olsen, Mr. Steve Kania, PLS 217 & PLS 394 (383) Greenhouse Hydroponic Classes and members of the Campus Ag. Center greenhouse staff.




Hydroponic Crop Production Experiential Education Program in Controlled Environment Agriculture

Dr. Patricia Rorabaugh, Plant Sciences, The University of Arizona

Every year, as part of our introductory (PLS 217) and advanced (PLS 394) classes in hydroponics and controlled environment agriculture, we perform an experiment to study some aspect of importance to the industry. Research topics have included comparisons of various types of non-soil rooting medias, comparisons of heat tolerant tomato varieties for use in warmer climates and the use of grafted as opposed to non-grafted tomato plants to possibly increase growth and yield. Students involved in this research gain academic knowledge of hydroponics and controlled environment agriculture as well as hands-on practical experience and skills in production techniques and cultural practices using tomatoes as a model plant. Those who have been involved in the research include students formally enrolled in the classes mentioned above, paid student workers, visiting scientists and students who are either involved in special programs or who require these skills for advanced work in other projects.
Cooperators: Dr. Merle Jensen, Dr. Chieri Kubota, Dr. Gene Giacomelli, and Technical support: Mr. Stephen Kania