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.
Christopher B. Kindred and J.M. Zajicek
B. Jez Lawrence and J.M. Zajicek
Root-zone temperature fluctuations and sap flow rates were characterized for several woody ornamental plants in a controlled environment using a water bath to control temperatures. Flow rates of sap in the xylem were measured every 15 seconds and averaged over 15 minute 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 raised from 22°C to 45°C (slightly below lethality between 9:00 am and 12:00 noon, held at that temperature until 4:00 pm, and then allowed to cool. There was a pronounced diurnal change in flow rate with peak flow during mid-morning declining in mid-afternoon. The decline in the rate of sap flow occurred at a faster rate than the decline in root-zone temperature. This diurnal flow rate was most pronounced during the first 24-hour elevated temperature cycle. Plants maintained at a constant temperature of 22°C showed no such extreme fluctuations in sap flow rate. Stomatal conductance measured with a porometer 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.
Jennifer L. Boatright and J. M. Zajicek
Hydrogel (Hydrosource™, Western Polyacrylamide, Inc.) was incorporated into 102 cm × 122 cm landscape beds at 25, 50, 75, or 100 lbs per 1000 sq ft. Weed barrier and 2 cm of pine bark mulch were added to the top of each bed. Controls consisted of 1) no hydrogel with weed barrier and mulch and 2) no hydrogel with mulch but no weed barrier. Each treatment was replicated four times with ten plants of petunia, marigold, and vinca planted per bed, for a total of forty plants of each species per treatment. Flower number of vinca and petunia increased with hydrogel incorporation, 75 lbs of hydrogel having the greatest number of flowers. Petunia also had higher visual ratings with increased hydrogel rates. Soil temperatures directly under the mulch and 10 cm below the mulch, at 1400 hr, were 49C and 40C respectively for controls, compared to 42C and 36C for beds with hydrogel.
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.
A.E. Pigg, T.M. Waliczek and J.M. Zajicek
Science and math achievement scores of third, fourth, and fifth grade elementary students were studied using a sample of 196 students from McAuliffe Elementary School, located in McAllen, Texas. The experimental group of students participated in a school garden program in addition to traditional classroom-based math and science methods, while students within the control group were taught math and science using only traditional classroom-based methods. No statistically significant differences were found in comparisons of science students' achievement scores, indicating that those students using the school garden program as an additional method to learn science benefited similarly to those who learned using only traditional science classroom-based instruction. However, results indicated statistically significant differences in comparisons of students' math achievement scores, showing that those students who received traditional math instruction had more improved math achievement scores compared to those taught using the school garden program. Results also found no statistically significant differences between gender and ethnic background comparisons. However, statistically significant differences in comparisons of grade levels showed that fourth graders benefited more, academically, from participation in the school garden program in comparison to other grade levels.
A.L. McFarland, T.M. Waliczek and J.M. Zajicek
Researchers have found that students' perception of their overall academic experience and the campus environment is related to academic accomplishment. Additionally, studies have found that the designed environment of the university can influence the degree of stress students may feel. The main objective of this study was to investigate the relationship between undergraduate university student use of campus green spaces and their perceptions of quality of life at a university in Texas. A total of 2334 students or 10% of the undergraduate student body received e-mails with information regarding the incentive for participation and instructions on accessing an online survey. The survey included questions that related to student use of campus green spaces, overall quality of life statements, an instrument to measure the quality of life of university students, and demographic questions. A total of 373 surveys was collected and analyzed to compare levels of quality of life of university students and the level of usage of campus green spaces. Demographic information collected allowed controlling for student grade classification, gender, and ethnicity. Frequency statistics determined that, on average, more than half the students were ranked as “high-users” of the campus green spaces, and very few students were considered “low-users.” Frequency statistics also determined that most students rated their overall quality of life and quality of life of university students positively. Additionally, this study found that undergraduate student use of campus green spaces and perceptions of quality of life were related to each other.
A.L. McFarland, T.M. Waliczek and J.M. Zajicek
Students' perception of their overall academic experience and the campus environment is related to academic accomplishment, and research has found that the designed environment of the university can influence the degree of stress students may feel. Past research found that undergraduate student use of campus green spaces and perceptions of quality of life were related to each other. The main objective of this study was to investigate the relationship between graduate student use of campus green spaces and their perceptions of quality of life at a university in Texas. A total of 347 of 3279 (≈10%) of the graduate student body received e-mails with information regarding the incentive for participation and instructions on accessing an on-line survey. The survey included questions that related to student use of campus green spaces, overall quality of life statements, an instrument to measure the quality of life of university students, and demographic questions. A total of 79 (22.8% response rate) graduate student questionnaires were collected and analyzed to compare perceptions of quality of life of university students and the level of individual usage of campus green spaces. Descriptive statistics determined that, unlike undergraduates who were primarily “high users” of campus green spaces, graduate students were about equally split between being “low,” “medium,” and “high users” of campus green spaces. However, graduate students still ranked their quality of life highly. Finally, this study found that, unlike undergraduates, graduate students did not have a statistically significant relationship between green-user scores and perception of quality of life scores. It may be that graduate students have less time to spend in outdoor spaces, yet still meet their quality of life needs through other means such as academic achievements.
Aime J. Sommerfeld, Tina M. Waliczek and Jayne M. Zajicek
A questionnaire based on the Life Satisfaction Inventory A (LSIA) was used to investigate older adult (age 50+ years) gardeners' and nongardeners' perceptions of personal life satisfaction and levels of physical activity. The LSIA measures five components of quality of life: “zest for life,” “resolution and fortitude,” “congruence between desired and achieved goals,” “physical, psychological, and social self-concept,” and “optimism.” Additional multiple-choice questions were asked to determine respondents' level of physical activity, perceptions of overall health and well-being as well as to gather demographic information. The survey was posted on a university homepage for ≈1 month. Responses were gathered from 298 participants who differentiated themselves as gardeners or nongardeners by responding positively or negatively to the question “do you garden?” Results indicated statistically significant differences in comparisons of overall life satisfaction scores with gardeners receiving higher mean scores indicating more positive results on the LSIA. Four individual quality-of-life statements included in the LSIA yielded statistically significantly more positive answers by gardeners when compared with nongardeners. Other questions regarding healthful practices revealed that personal reports of physical activity and perceptions of personal health were statistically significantly more positive among gardeners when compared with nongardeners.