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- Author or Editor: Carl Motsenbocker x
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Field and greenhouse studies examined the fruit detachment force (FDF) and fruit and pedicel characteristics of two lines of tabasco pepper (Capsicum frutescens L.) at several stages of maturity. The detachment force of red-mature `McIlhenny Select' fruit at the calyx-fruit detachment area was lower than that of less mature fruit stages. The force required to detach red-mature Hard Pick (HP) tabasco fruit was higher than that of redmature `McIlhenny Select' fruit in the field and greenhouse. The fruit detachment force of red field-grown HP fruit was higher, and in the greenhouse was lower, than that of green or breaker fruit. HP fruit of all maturity stages, except red-mature, separated similarly to `McIlhenny Select' fruit with little or no fruit tissue attached to the calyx. Fruit detachment force was not correlated with any fruit or pedicel characteristics studied.
A garden-based science curriculum (Junior Master Gardener) was introduced into public elementary schools as an informal education program conducted by Master Gardener volunteers and service-learning university students. The program was held once a week for 2 hours during regular school hours with fifth grade classes. The service-learning students were enrolled in a senior level horticultural science education class. Students were surveyed pre- and post-program with the Science Teacher Efficacy Belief Instrument (STEBI-B, preservice), a background survey instrument, and weekly journals. There were significant differences in the students' perceived teaching efficacy pre- and post-program. Most of the student's STEBI scores either remained the same or increased over the semester. Overall, the service-learning college students had very positive responses to their experiences as teachers and mentors in public elementary schools. In addition, the students were able to use their horticultural skills and knowledge and they also gained an appreciation for the teaching profession.
Pepperoncini pepper (Capsicum annuum var. annuum L. `Golden Greek') was grown at in-row spacings of 7.5, 15, 22.5, 30, and 45 cm to determine the effect of plant population on growth and fruit yield in a 2-year field study. In 1992, pepper plants grown at the 15-cm in-row spacing had the lowest plant, stem, and leaf dry weights, while plants at the lowest density (45-cm spacing) had the highest plant, leaf, and stem dry weights and the largest leaf area (LA). Of plants grown at the 7.5-cm spacing, the total yield and fruit count per hectare were higher than at the other spacings; however, fruit yield per plant was lowest. In 1993, the lowest plant and leaf dry weights and LA and highest LA index (LAI) were from plants at the 7.5-cm in-row spacing. Plants at the 45-cm spacing had the highest plant and leaf dry weight and LA and the lowest LAI. Pepper plants grown at the narrowest spacing produced the lowest early and total fruit yield per plant but the most fruit per hectare. In general, plants grown at the narrowest spacings produced the smallest plant, leaf, and stem biomass but resulted in the highest fruit yields and counts per hectare and the lowest fruit yields per plant.
An organic gardening class was developed to provide nonhorticulture students an opportunity to become acquainted with horticultural science and the basics of gardening organically. The course was developed as a 3-hour (1 hour lecture, 2 hours lab), two-credit course taught in the fall semester using an organic gardening textbook. A major component of the lab is the development and maintenance of a small individual garden plot during the semester. Students grow their own plant materials, plant, fertilize, and monitor pests, and harvest at the end of the semester. The organic gardening class was taught for 7 years and evolved into having a mandatory service-learning component that supports service projects in the local community. Projects included working with the local farmers' market, supporting school projects such as growing plants, school grounds beautification, gardening, or mulching, and gleaning product from research and garden plots for the local food bank. The poster will provide information on the class syllabus and materials, record of service projects, and reflections of the students during and at the end of the class.
`McIlhenny Select' (easy detachment) and `Hard Pick' are two lines of tabasco pepper (Capsicum frutescens L.) that differ in the fruit detachment characteristics. Cellulase (Cx) and polygalacturonase (PG) activity, extracted from the fruit abscission zone, correlated inversely with the force needed to separate the fruit from the pedicel. A trend of higher Cx and PG is associated with the lower detachment force in the McIlhenny Select line. Differences in the fruit cell wall protein profile between both lines occurred during ripening. Two bands of 23 kDa and 40 kDa were higher in `McIlhenny Select'. A band of approximately 30 kDa was higher in `Hard Pick', while a band of ≈70 kDa increased in both lines. Isolation and characterization of these bands as well as Cx and PG is needed to understand the factors affecting fruit detachment in tabasco pepper.
Two tabasco pepper (Capsicum frutescens L.) lines were previously identified that differ in fruit detachment characteristics. Ethephon treatment (1000 μl/L) to intact tabasco fruit 29 days after anthesis (green-mature) enhanced ripening as indicated by fruit coloration in both lines. `McIlhenny Select' fruit, which normally separate readily at the red-mature stage, however, had a quicker ripening response compared to `Hard Pick' fruit. Ethephon increased cellulase activity in the fruit tissue of both tabasco lines compared to the untreated control, and there was a trend of higher cellulase activity in `McIlhenny Select' compared to `Hard Pick'. Differences in ripening and enzyme activity in response to ethylene generators indicate that the two tabasco lines are suitable material to investigate the physiological processes involved in pepper fruit ripening.
Red-mature Tabasco (Capsicum frutescens) fruit (`McIlhenny Select') normally separate easily at the junction of the fruit and receptacle or calyx. Differences in fruit detachment force (FDF) between two lines, one that separates readily (`McIlhenny Select') and one that does not (`Hard Pick'), have been reported previously (Motsenbocker et al., 1995). In this study, enzyme activity from the detachment area was analyzed by viscosity reduction. The reaction mixture was 0.3% pectin in 20 mm NaAc, pH 5.5, for polygalacturonase (PG) and 0.6% carboxymethyl cellulose (CMC) in 20 mm NaPO4, pH 6.0, for cellulase. Preliminary data indicated that PG and cellulase enzyme activity increased during fruit ripening in both lines. Only cellulase activity, however, correlated with FDF. In addition, the activity of both enzymes was higher in the `McIlhenny Select' line than the `Hard Pick' line at the orange and red-mature stages.
Twenty-seven triploid watermelon cultivars and/or breeding lines were evaluated for yield and quality components. Total yield, rind thickness, mature and immature seed count, incidence of hollow heart, soluble solids, sugars, pH, titratable acidity, and internal color were measured for each cultivar/breeding line. Yields ranged from 32,000 to 66,000 kg per hectare. `Jack of Hearts' was the highest yielding cultivar. Hollow heart was moderate to severe in five of the genotypes. Except for two breeding lines, soluble solids were at least 11 per cent. Rind thickness ranged from 15.0 to 22.2 mm. Little or no mature seed was present in most of the genotypes. The cultivar `Millionaire' and the CLF breeding lines, with the exception of CLF 1016, contained the most mature seeds. A range of internal color and individual sugar content (fructose, glucose, sucrose) existed between genotypes.
Field and greenhouse studies were conducted to examine fruit detachment force and plant parameters of two strains of Tabasco (Capsicum frutescens) at different stages of maturity. The detachment force of mature red `McIlhenny Select' at the fruit-receptacle detachment area was less than that of breaker and mature green fruit. `McIlhenny Select' separated cleanly at all stages of maturity. A wild type Tabasco strain `HP' did not abscise at the red mature stage; fruit detachment force was greater than that of `McIlhenny Select'. The detachment force of mature green and breaker `HP' fruit were similar to those of `McIlhenny Select' at the same stage of maturity. Fruit weight, length, and width of the two tabasco strains were not different. The utility of the `McIlhenny Select' and `HP' strains for physiological studies of pepper fruit abscission will be discussed.
Tomato is an important vegetable crop in Louisiana for small- to large-scale growers. Growers often use protected cultivation with structures, such as greenhouses, in order to take advantage of higher prices early in the season and increase profits through increased tomato yield and quality. A negative aspect of greenhouse use is the high investment and production costs associated with these structures. High tunnels, or simple greenhouse-like structures, have been used to protect crops from cold temperature in northern states, as they often provide benefits similar to greenhouses with considerably lower cost. Very little research has been conducted on the use of high tunnels for crops in the southern states. High tunnels in combination with row covers were evaluated for field cultivation of spring season fresh market tomato in Louisiana. The studies were set up in a randomized complete-block design with three replications. Tomatoes were transplanted into single rows on four-row raised beds covered with black plastic mulch on 1.2-m centers on 13 Mar. 2004. Row covers were installed immediately after transplanting and removed on 3 May. Plants were harvested for 6 weeks starting 12 May 2004. Both high tunnels and row covers significantly increased minimum and maximum air temperatures at a 15-cm height compared to the black plastic mulch control. Early yield was highest with the tunnel treatment without row cover compared to tunnel with row cover and similar to row cover alone or the control. There were no differences in total marketable yield between treatments. Research results from 2 years will be presented.