Search Results
A recycling nutriculture system was redesigned to improve growth and flowering of Tagetes erecta L., cv., Inca Yellow in four media; loose rockwool (RW), coal bottom ash (CBA), pinewood peelings (PWP) and CBA:PWP (1:1, v/v). Three nutricycle frequencies of 12, 6 and 4 per 12 hour light period were set with a nutricycle duration of 5 minutes. Volume, height and fresh and dry weights of marigolds in CBA, PWP and CBA: PWP were comparable to that of marigolds in RW. Flower diameters of plants in CBA, PWP and CBA:PWP were increased and days to harvest decreased compared to plants in RW. Plants in CBA: PWP increased in fresh weight compared to CBA or PWP plants. No interaction occurred between media and nutricycle frequency at 12 or 4 cycles per 12 hours; however a malfunctioning timer caused prolonged flooding of plant root zones at the 6 cycle setting. This resulted in decreased plant volume and fresh and dry weights at this frequency. These results show that growth and flowering of marigolds in CBA and PWP comparable with that in RW can be achieved with more than 1 nutricycle frequency.
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%.
The objective of this study was to determine the relationship between temperature and color development in 3 strains of Red Delicious apple (Malus domestica Borkh). The strains `Scarlett Spur', `Ultrastripe' and `Starkrimson' were chosen based on variation in coloration. Chromaticity values (L* a* b*) were measured with a Minolta CR-200b calorimeter on 5 tagged apples on each of 4 trees of each strain. Measurements were made at approximately the same location on each fruit 23 times from July 11 through September 25, 1989. Differences in a*/b* ratio among strains were observed as early as the first sampling date; with `Scarlet Spur' having the highest ratio and `Starkrimson' the lowest. These differences were maintained for most the growing season. Temperature below 21C tended to enhance color development, whereas temperature above 21C reduced coloration. Temperature affected all 3 strains similarly.
The objective of this study was to determine the relationship between temperature and color development in 3 strains of Red Delicious apple (Malus domestica Borkh). The strains `Scarlett Spur', `Ultrastripe' and `Starkrimson' were chosen based on variation in coloration. Chromaticity values (L* a* b*) were measured with a Minolta CR-200b calorimeter on 5 tagged apples on each of 4 trees of each strain. Measurements were made at approximately the same location on each fruit 23 times from July 11 through September 25, 1989. Differences in a*/b* ratio among strains were observed as early as the first sampling date; with `Scarlet Spur' having the highest ratio and `Starkrimson' the lowest. These differences were maintained for most the growing season. Temperature below 21C tended to enhance color development, whereas temperature above 21C reduced coloration. Temperature affected all 3 strains similarly.
`Inca Yellow' marigolds (Tagetes erects L.) were planted in polyethylene bags containing coal bottom ash (CBA), pine wood peelings (PWP), a mixture of 1 CBA: 1 PWP (v/v), and loose Grodan rockwool (RW) and grown in a circulating nutriculture system. Three fertigation frequencies of 12, 6, or 4 cycles per 12-hour light period were set with a duration of 5 minutes each. Flower diameters of marigolds grown in CBA, PWP, and CBA-PWP exceeded flower diameters of RW-grown marigolds, and days from planting to harvest were less in CBA and CBA-PWP than in the other two media. There was no interaction between medium and fertigation frequency. Foliar analysis showed no significant differences in plant elemental composition among root media or fertigation frequencies. Postharvest PWP water extracts contained higher P levels than extracts of other media, and CBA-PWP water extracts contained higher K, Ca, and Mg. In the CBA-PWP mixture, decomposition products from PWP may have increased P volubility and solubilized the K, Ca,-and Mg-in CBA.
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.