Studies in human issues in horticulture have focused on how gardens affect the self-development typically in non-traditional or special populations. As the science of people–plant research expands, many populations are being investigated, including youth. As we study the effects of horticulture on self-development of youth, it is important to cross the boundaries between technical horticulture and disciplines such as psychology and education. Tools that have been used traditionally in these other disciplines have been adapted to study the effects of gardening on children. Two major areas of research will be reviewed, including: 1) The effects of gardening and school ground landscaping on the self-development, environmental attitudes and horticulture knowledge of mainstream school children, and 2) The evaluation of horticulture programs established for at-risk youth and juvenile offenders.
Sonja M. Skelly and Jayne M. Zajicek
Project GREEN (Garden Resources for Environmental Education Now) is a garden program designed to help teachers integrate environmental education into their classroom using a hands-on tool, the garden. The objectives of this research project were to 1) develop an interdisciplinary garden activity guide to help teachers integrate environmental education into their curricula and 2) evaluate whether children developed positive environmental attitudes by participating in the activities. Students participating in the Project GREEN garden program had more positive environmental attitude scores than those students who did not participate. Second-grade students in the experimental and control groups had more positive environmental attitudes than fourth-grade students. In addition, this research found a significant correlation between the number of outdoor related activities students had experienced and their environmental attitudes.
Michael R. Sweatt and Jayne M. Zajicek
Castilleja indivisa grows hemiparasitically attached to the roots of various nearby plants. Studies were done using several host plants to determine the effects of the parasitic relationship on the growth of C. indivisa and the host plants. Transpiration rates, and leaf water potentials of C. indivisa, and various hosts, were also measured at various soil moisture levels. Carbon transfer between C. indivisa and each host was examined using a 14CO2 tracing technique.
The various hosts used in this experiment enhanced the growth of C. indivisa by 200-700% compared to non-parasitic controls. Transpiration rates of non-parasitic controls remained relatively low at all soil moisture levels while transpiration rates of parasitic C. indivisa increased rapidly as soil moisture increased, and generally exceeded that of its host at low to medium soil moisture levels. Leaf water potentials of non-parasitic controls were generally more negative than other treatments. Carbon exchange between C. indivisa and its hosts was insignificant and appears not to be a major nutritional factor.
Beth Jez Lawrence and Jayne M. Zajicek
Sap flow rates of three Cercis spp. exposed to supraoptimal root-zone temperatures were characterized in a controlled environment chamber using a water bath to control temperatures. Flow rates of sap in the xylem were measured every 15 sec. and averaged over 15 min. intervals. Sap flow measurements were correlated to root-zone temperatures recorded during the same time intervals. Whole plant transpiration was measured gravimetrically. Root-zone temperatures were maintained at 22C for three consecutive 24-hr cycles and then increased to 45C for an additional three 24-hr periods. All plants, regardless of species, had reduced sap flow patterns when exposed to high root-zone temperatures. Plants maintained at a constant temperature of 22C showed no extreme fluctuations in sap flow rate. Stomatal conductance rates and leaf water potentials showed similar trends to whole plant transpiration.
Jayne M. Zajicek and J.L. Heilman
A study was conducted to explore how surface materials, including pine bark mulch, bare soil, and turfgrass, affect water use of diverse cultivars (dwarf weeping, dwarf upright, standard weeping, and standard upright) of crape myrtle (Lagerstroemia indica L.). Daily water use was measured gravimetrically, and instantaneous rates of sap flow were measured using heat balance stem flow gauges. Plants of all cultivars surrounded by the mulched surface lost 0.63 to 1.25 kg·m-2·day-1 more water than plants on the soil surface and 0.83 to 1.09 kg·m-2·day-1 more than plants surrounded by turf. The surface temperature of the mulch was higher than that of the other surfaces, resulting in greater fluxes of longwave radiation from the surface. Because of the greater energy load, plants on the mulched surface had higher leaf temperatures and higher leaf-air vapor pressure deficits (VPD) throughout the day. Plants on the mulched area also had higher stomata1 conductances during most of the day compared with those on bare soil and turfgrass surfaces.
Sarah E. Lineberger and Jayne M. Zajicek
Nutrition in the Garden is a garden program designed to help teachers integrate nutrition education into their classroom using a hands-on tool, the garden. The objectives of this research project were to 1) develop a garden activity guide to help teachers integrate nutrition education, specifically as it relates to fruit and vegetables, into their curricula, 2) evaluate whether students developed more positive attitudes towards fruit and vegetables by participating in the garden program, and 3) evaluate whether students developed better nutritional behavior by eating more fruit and vegetables after participating in the garden program. Students' nutritional attitudes regarding fruit and vegetables were measured with a fruit and vegetable preference questionnaire divided into three sections targeting vegetables, fruit, and fruit and vegetable snacks. Students' nutritional behaviors regarding fruit and vegetables were evaluated through 24-hour recall journals. After gardening, students' attitudes towards vegetables became significantly more positive. In contrast, no differences were detected in attitudes towards fruit. Students also had more positive attitudes towards fruit and vegetable snacks after gardening, with female students and younger students having the greatest improvement in snack attitude scores. Even though school gardening improved students' attitudes towards vegetables, fruit and vegetable consumption of students did not significantly improve due to gardening. Overall, the average daily fruit and vegetable consumption of the students participating in the Nutrition in the Garden study was 2.0 servings per day. This falls short of the estimated national average for daily fruit and vegetable consumption for this age group (3.4 servings) and extremely short of the nationally recommended 5.0 servings per day.
Kimberly A. Poff and Jayne M. Zajicek
Uniconizole has great potential for use in both the landscape and nursery industry for improved plant quality, more efficient maintenance techniques, and increased water conservation. A study was conducted to evaluate the effects of uniconizole and methods of application on growth, development, and water use of asiatic jasmine and vinca. Treatments consisted of 1.25 mg A.I., 2.5 mg A.I., or 5 mg A.I. applied in a 25 ml spray or 25 ml soil drench. Another study was conducted to determine if the growth regulation effects could be overcome by direct application of GA. GA3 and GA4+7 were applied at rates of 2.5 mg A.I., 12.5 mg A.I., or 25 mg A.I. in a 25 ml solution after growth reduction had occurred. The 5 mg A.I. uniconizole spray and drench treatments were most effective in reducing growth and whole plant transpiration for asiatic jasmine and vinca respectively. Transpiration per unit leaf area was not reduced for any treatment except for asiatic jasmine at the highest drench rate.
Jayne M. Zajicek and Christine D. Townsend
Placing the horticulture student on a path of professional development as a society-ready graduate for the 21st century takes more than technical knowledge. New types of team-oriented organizations are being created that were not even imagined a few years ago. To help empower students to survive in these organizations, the course “Leadership Perspectives in Horticulture” was created. This interdisciplinary course serves as a model for leadership skill instruction by incorporating the component of leadership development into a technical horticulture course. The objectives of this course are to provide academic and historical perspectives in technical horticulture issues, develop skills in leadership, problem solving, and team building, complete a theoretical study of specific leadership models, and blend theoretical leadership models with horticulture issues by completing a problem solving experience. An overview of the course in addition to changes in leadership behavior of students will be discussed.
Jayne M. Zajicek and Jennifer C. Bradley
Floral Design (HORT 203) is an increasingly popular course offered at Texas A&M Univ. HORT 203 is offered as a university core curriculum humanities elective and, thus, enrolls many nonhorticulture majors, averaging 95 students per semester. HORT 203 is taught in a large lecture room that does not always lend itself to teaching a hands-on, visual design course. To increase student understanding of the materials, traditional 35-mm slides and overhead transparencies are being replaced by visual computer technology. Colorful, scanned-in images of floral designs are created in Microsoft PowerPoint and incorporated into computer presentations and color transparencies that supplement each instructional presentation. In addition, the Internet is incorporated in the course by providing students with instructors' and lab assistants' e-mail addresses, individual lab section pages, slides for plant identification, reading assignments, as well as classroom lectures. The technologies used for HORT 203 enhance student understanding and ease of teaching while providing a visual alternative to traditional teaching methods. The technologies used for HORT 203 will be discussed and demonstrated including a tour of home-pages, lectures, and plant id lists.
Carolyn W. Robinson and Jayne M. Zajicek
The goal of this study was to assess changes in the life skill development of elementary school students participating in a 1-year school garden program. The Life Skills Inventory included statements for six constructs of life skills including teamwork, self-understanding, leadership, decision making skills, communication skills, and volunteerism. The students were divided into two treatment groups, an experimental group that participated in the garden program and a control group that did not participate in the school garden program. Students in the control group had significantly higher overall life skills scores on the pretest compared to students participating in the garden program but the scores were no longer significantly different between the groups on the posttest scores at the end of the program. In addition, there were no significant differences in the control group's pretest scores compared to their posttest scores. However, the students in the experimental group did significantly increase their overall life skills scores by 1.5 points after participating in the garden program. Two internal life skill scales were positively influenced by the garden program; “working with groups” and “self understanding.”