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.
Jayne M. Zajicek and J.L. Heilman
Shari Koch, Sarah Lineberger, and J.M. Zajicek
The Citrus Guide, Teaching Healthy Living Through Horticulture (Citrus Guide) is an activity guide designed to help teachers integrate nutrition education into their classrooms. The objectives of this research project were to: 1) help teachers integrate nutrition education, specifically as it relates to citrus fruit, into their curricula by using the Citrus Guide; and 2) evaluate whether students developed more positive attitudes towards citrus fruit by participating in activities from the Citrus Guide. The nutritional attitudes of 157 second through fifth grade students were measured with a citrus fruit preference questionnaire divided into two sections: one targeting citrus fruit and the other targeting citrus snacks. After participating in the activities, no differences were detected in attitudes towards citrus fruit. However, students did have more positive attitudes towards citrus snacks after participating in the activities, with female students and younger students having the greatest improvement in citrus snack attitude scores. Also, there was a direct positive correlation between more grapefruit and oranges consumed daily and students' attitudes towards citrus fruit.
Jennifer C. Bradley and J.M. Zajicek
A current trend in environmental practices concerns using constructed wetlands for wastewater treatment. The ecological values of wetlands have long been known. Wetland plants aid in the treatment of water pollutants by improving conditions for microorganisms and by acting as a filter to absorb trace metals. Wetlands now are being considered for industrial, municipal, and home wastewater treatment. Constructed wetlands are an economical and environmentally sound alternative for treating wastewater. These constructed “cells” are designed to function like natural wetlands. In constructed wetlands, water flow is distributed evenly among plants in a cell where physical, chemical, and biological reactions take place to reduce organic materials and pollutants. Increasing numbers of environmentally conscious homeowners are installing wetland wastewater treatment systems in their backyards with the aid of licensed engineers. This installation is occurring despite of the lack of educational materials to aid in site selection, selection of appropriate plant materials, and long-term maintenance. Traditional wetland plant species currently are being selected and planted in these sites, and the resulting effect is often an unsightly marsh appearance. With increasingly more homeowners opting for this alternative system, a strong need exists for educational materials directed at this audience. Therefore, educational resources that can provide information to the public regarding the benefits of wetland wastewater systems, while promoting aesthetically pleasing ornamental plant species is needed. A hands-on guide for installing constructed wetlands, a home page on the World Wide Web, and an instructional video currently are being developed at Texas A&M Univ. These technologies will be demonstrated and the values, needs, and opportunities available for the horticultural industry in the area of wetland construction will be discussed.
Christopher B. Kindred and J.M. Zajicek
Survivability of ornamental landscape plants during transport and the early stages of transplanting is a concern of the nursery and landscape industries. An effective antitranspirant may help avoid unnecessary plant losses during these periods of plant stress. The objective of this study was to evaluate the effects of a new experimental antitranspirant on whole-plant transpiration of two ornamental landscape shrubs. Plants of Hibiscus rosa-sinensis and Photinia ×fraseri were treated with the experimental antitranspirant N2001. Treatment rates included: 0% (as a control), 10%, 12.5%, or 15%. All treatments were mixed as a percentage of N2001 in a given volume of reverse osmosis water and applied to the roots as a drench. Whole-plant transpiration was determined gravimetrically by weighing the plants daily. Stem-flow gauges further monitored daily water use on an hourly basis. At the termination of the experiment, leaf areas and leaf dry weights were determined. Application of the antitranspirant reduced whole-plant transpiration immediately for all treated plants compared to that of control plants. On day 1, the 10%, 12.5%, and 15% treatments significantly reduced whole-plant transpiration levels by 41%, 50%, and 62%, respectively, compared to untreated plants. On day 3 and 4, the antitranspirant was still effective, reducing whole-plant transpiration by 47% and 24% on average, respectively, compared to untreated plants. By day five there were no significant differences in whole-plant transpiration between any treatment. Differences in whole plant transpiration can be attributed to antitranspirant application due to lack of differences in leaf area, dry weight or leaf area ratio between any treatment.
T. M. Waliczek, J.C. Bradley, and J.M. Zajicek
Children's gardens are receiving increased attention from communities and schools. Educators recognize that gardens provide beauty, produce and education, and serve as an outlet in which gardeners may gain personal benefits. The objectives of this research study were to evaluate whether children participating in garden activities benefited by an improvement in interpersonal relationships and attitudes toward school. No significant differences were found between pre- and posttests and the control and experimental group comparisons. However, demographic comparisons offered interesting insight into trends in the data. Female students had significantly more positive attitudes towards school at the conclusion of the garden program compared to males. The results also showed that there were differences in interpersonal relationships between children depending on grade level in school. In addition, childrens' attitudes toward school were more positive in schools that offered more intensive individualized gardening.
O.M. Aguilar, T.M. Waliczek, and J.M. Zajicek
The objectives of this study were to examine an interdisciplinary and experiential approach to environmental education by use of a youth gardening program for third through fifth grade students. In addition, this study evaluated the gardening program's effectiveness on promoting positive environmental attitudes and a high environmental locus of control with children. A questionnaire was developed from three existing instruments and was used to collect information concerning environmental attitudes, locus of control as it related to environmental actions, and demographic information of respondents. No statistically significant differences were found on either variable in comparisons of experimental and control group responses. However, students from both groups exhibited positive environmental attitudes. Demographic comparisons indicated that children with previous gardening experience scored significantly higher on the environmental attitude and environmental locus of control statements when compared with children without gardening experience. Girls scored significantly higher than boys on environmental attitude and environmental locus of control scores. Caucasians scored significantly higher when compared with African-Americans and Hispanics on environmental attitude scores, and Caucasians scored significantly higher when compared with African-Americans on environmental locus of control scores.
June Wolfe III, J.M. Zajicek, and M.A. Hussey
Six native Texas and six introduced ornamental grass species were chosen for an evaluation of water use performance and aesthetic value under drought stress to identify material most appropriate for water conserving landscapes. Greenhouse and field experiments determined the overall performance of the grasses under drought conditions. A public survey evaluated the aesthetic value of investigated species. Greenhouse work determined that examination of total chlorophyll content was not a useful parameter for predicting drought stress. Water use and visual aesthetic decline rates were determined for all species in the greenhouse. On average, native and introduced species performed equally well. Imperata cylindrica exhibited the lowest rates of water use (by 92%) and visual decline (by 51%) in the greenhouse and was the most conservative water user in the field with lowest stomatal conductance (by 76%). The survey found that grasses were acceptable as ornamentals in the landscape and natives and introduced species equal in preference.
Tina M. Waliczek, R.D. Lineberger, and J.M. Zajicek
The kinderGARDEN website (http://aggie-horticulture.tamu.edu/KINDER/index.html) was developed as part of the Aggie Horticulture network. Its focus was to help incorporate fun garden activities into the home and school lives of children. The page has grown to include pages on school gardens, community gardens, botanical gardens, and a fun page for kids. The site focuses toward providing information on activities and curricula developed for children. A survey, designed to investigate the perceptions of parents and teachers working with youth in gardening situations on the benefits of children gardening, is included on the site. Adults who work with children in any type of gardening situation can respond to the survey via e-mail. Questions on the survey relay information about the type of gardening situation in which the children participate, how many children are involved, the types of crops grown, the relationship of the adult to the child, and what kinds of benefits the adults observe in the children. Results and conclusions of the survey instrument will be presented. The positive aspects and drawbacks of this research technique will be discussed.
T.M. Waliczek, P. Logan, and J.M. Zajicek
The main objective of this study was to investigate the impact of an outdoor environmental program, Math and Science in the Outdoor Classroom, on elementary grade students' creative and critical thinking, and attitudes toward math and science. Math and Science in the Outdoor Classroom is an on-campus nature program in Santa Fe, N.M. Students participated in half-day programs focusing on topics such as water, insects, soil, and weather. Twenty-one teachers from five schools volunteered 175 second through sixth graders to participate in the program and research study. Surveys were administered to students, teachers, and volunteers after completion of the program. Interview data was analyzed using QSR NUD*IST (Nonnumerical Unstructured Data Indexing Searching and Theory-building) computer-assisted qualitative data analysis system to examine respondents' perceptions of the program using Bloom's taxonomy as a theoretical framework. Results indicated that students not only learned math and science at the lower levels of Bloom's taxonomy, but were also thinking at the higher levels of synthesis and evaluation within the framework.
S. Koch, T.M. Waliczek, and J.M. Zajicek
Fifty-six children were included in a study that evaluated the effectiveness of a garden program designed to teach health and nutrition to second through fifth grade-level children. The specific objectives of the research project were to evaluate the effect of the program on nutritional knowledge of the benefits of eating fruit and vegetables, nutritional attitudes toward fruit and vegetables, and eating behaviors of children, specifically consumption of fruit and vegetables. Children's nutritional knowledge was measured with an 11-question multiple-choice exam based on the educational activities performed. Children's nutritional attitudes regarding fruit and vegetables were measured with a fruit and vegetable preference questionnaire, and children's eating behaviors were evaluated with an interview question asking them what they ate for a snack that day. After participating in the nutritional program, children's knowledge about the benefits of eating fruit and vegetables significantly improved, but there were no significant differences found in participants' attitude scores toward fruit and vegetables. However, the participants did report eating healthier snacks after participation in the nutritional program.