Firmness, soluble solids concentration (SSC), starch index (SI), internal ethylene concentration (IE), and titratable acid concentration (TA) of `York Imperial' apple (Malus ×domestica Borkh.) fruit changed linearly with harvest date between 152 and 173 days after full bloom (DAFB). Firmness was positively correlated with TA, SSC was correlated with SI, and SI was negatively correlated with TA. After 150 days of refrigerated-air (RA) storage, there was no relationship between DAFB at harvest and firmness or superficial scald, but the malic acid concentration declined linearly and storage decay increased linearly with DAFB. Firmness had declined to a plateau and was not correlated with any variable at harvest. Malic acid concentration after CA storage was correlated with DAFB, firmness, SSC, and SI; scald was correlated with firmness and SI; and decay was correlated with DAFB, firmness, SSC, and SI. During 150 days of controlled-atmosphere (CA) storage (2.5% O2, 1.0% CO2), firmness and TA decreased as a linear function of DAFB. Percentage of fruit with scald and scald rating changed quadratically with DAFB, and decay increased linearly with DAFB. After 150 days of CA, firmness was correlated with DAFB, SI, and IE at harvest; TA was correlated with DAFB, firmness, SSC, TA, and SI; scald was correlated with firmness and SI; and decay was correlated with DAFB, SSC, and scald index at harvest. During 250 days of CA storage, firmness, TA, scald, and decay changed linearly with DAFB in only 1 or 2 years out of 3. Formulas were created to predict firmness after CA within 10 to 12 N (2.0–2.5 lb-f) and TA to within 25%.
Morris Ingle, Mervyn C. D'Souza, and E.C. Townsend
Amy N. Campbell, J.M. Zajicek, and C.D. Townsend
A study was developed to compare secondary high school students' knowledge and attitude changes toward environmental issues after the completion of an interdisciplinary instructional unit in environmental science. The population for the study was high school horticulture and environmental science students. The study consisted of four student groups, including two control groups and two experimental groups, one each from an environmental science class and a horticulture class. The control groups did not participate in the treatment, which consisted of an environmental mini-unit and plant propagation experiment that the experimental groups completed. Both student groups responded to a pre- and posttest questionnaire. There were no significant differences in overall attitude scores between treatment and control groups. Significant differences were noted in knowledge gains between the horticulture control group and treatment group, with students participating in the mini-unit scoring significantly higher in knowledge gain. There was also a positive correlation between attitude scores of students who had success with their propagation experiments. The results of this study indicate that it is important to test students' attitudes and knowledge when determining the effectiveness of new environmental curriculum. The high correlation between success in the propagation experiment included in the miniunit and attitude supports findings that an activity-based curriculum has the potential to raise the awareness of students on environmental issues.
Amy N. Campbell, T.M. Waliczek, J.C. Bradley, J.M. Zajicek, and C.D. Townsend
As human pressures on the environment increase and as conflicting demands on education become focused, schools have a greater responsibility to educate children to care for their environment. Results from this study demonstrated that students who were involved in the actual propagation and restoration of ecosystems, and who had positive experiences in doing so, were more likely to have positive environmental attitudes.
Suman Singha, Tara A. Baugher, Edwin C. Townsend, and Mervyn C. D'Souza
Fruit of 10 `Delicious' apple (Malus domestica Borkh.) strains were harvested 149 days after full bloom in 1988. Fruit color was measured at four locations on each fruit at the midpoint between the stem and calyx end with a Minolta CR-200b portable tristimulus calorimeter. Anthocyanin content of corresponding skin disks was determined spectrophotometrically. Significant differences existed among strains in both the amount and distribution of anthocyanin around the fruit. High-coloring strains had a significantly higher anthocyanin concentration at both the blushed and the nonblushed surface when compared to low-coloring strains. A linear regression of anthocyanin content on the ratio of (a*/b*)2 provided an R2 = 0.59; precision was enhanced by using a separate equation for each strain (R2 = 0.80). Regressing log (anthocyanin) on L* using two linear splines yielded an R2 = 0.78. These relationships allow the use of a portable calorimeter for rapid, nondestructive estimation of fruit anthocyanin content in situ.
Jennifer C. Bradley, J.M. Zajicek, C.D. Townsend, and G.E. Briers
The objectives of this research project were to: 1) Develop an environmental science curriculum that was heavily activity-based, 2) evaluate the curriculum for usefulness as a teaching tool, and 3) test student knowledge and attitude changes towards the environment resulting from exposure to this 10-day curriculum unit. The curriculum developed entitled Environmental Technology—”Natural State of the Environment” was designed to provide an introduction to biological processes and basic principles of ecology, and to set the foundation for additional environmental studies. The curriculum was sent to 31 high schools in Texas and tested on 1500 students. Students participating in this study were administered a pretest prior to participation in the environmental science curriculum and an identical post-test after its completion. The questionnaire included an attitude inventory and knowledge section in addition to a biographical information section. Results examine the relationship between environmental knowledge and environmental attitudes, determine the attitude and knowledge changes from before until after the instructional unit, and focus on the importance and need for environmental education programs.