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A simple-leaved pecan [Carya illinoensis (Wang.) K. Koch] seedling was found in a Riverside seedling nursery by Larry Womack of Womack Nurseries, DeLeon, Texas. This uncommon specimen was preserved by grafting it to a normal pecan seedling rootstock sometime in the early 1960’s. Wood from the variant was grafted on orchard seedlings at the U. S. Pecan Field Station, Brownwood, Texas, in April 1973 and on 1-year-old greenhouse-grown Riverside seedlings in Feb. 1974. This paper reports observations of the growth and gross morphology of this unusual variant.

Open Access

With the increasing use of computers in the horticulture industry, advisory committees are recommending computer literacy training. Database management software is a tool students can use to enhance the learning of plants and obtain handson experience with computers. Students in an herbaceous plant materials course develop a plant database and create a companion flash card set from printed database records and pictures. Benefits of the project are: Improved memorization of plant information, enhanced information research skills, and use of a tool in later design activities. Other horticulturally related courses, including woody plant materials and pest management, can use the activities to achieve similar benefits.

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Graduates of horticulture curricula are expected to be able to convey technical expertise in a variety of communication and writing activities. To address the need for writing competence, writing-across-the-curriculum concepts are being applied in a variety of horticulture courses. To expand writing skills in a turfgrass management course using a job-related activity, a newsletter project was assigned to students that required the students to write two articles and produce a newsletter publication.

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Suitable parents for the production of F1 hybrid seed between almond and root-knot nematode resistant peach were selected. Three of 13 almond selections were found which, when pollinated by ‘Nemaguard’ pollen, produced good sets of seed. When germinated, their seedlings showed good root-knot nematode resistance, hybrid vigor, and exceptional compatibility with almond tops.

The self-incompatibility of almond was used to permit natural pollination between selection CP5-33 and a selected seedling of ‘Nemaguard’, 3-28. The F1 hybrids proved to be very compatible as rootstocks with almond and peach tops and imparted increased vigor to them.

Both ‘Nemaguard’ and a selected seedlings of ‘Nemaguard’ served as good pollen parents. ‘Okinawa’ peach, another rootknot nematode resistant peach type rootstock, was a less satisfactory pollen parent.

Open Access

Abstract

Pricing performance in the marketing systems for lettuce, carrots and tomatoes was found to be generally consistent with models based on the competitive model in space, time, and form. Weekly prices at various f.o.b. shipping points and 12 selected wholesale terminal markets moved together throughout the winter seasons of 1966-68. Gross margins (the difference between shipping point and wholesale terminal market prices) were related to distance, the perishability of the vegetable, and the wholesale terminal market price.

At shipping point, weekly prices of vegetables were functions of the quantity available. In addition, temp and rainfall variables as proxies for disease and size were significantly related to prices as was the quantity of vegetables marketed during the previous 2 weeks. The analysis indicated adjustments in institutions and market information systems may be needed. Results with tomatoes were less satisfactory than with lettuce and carrots because of the complexity of the tomato market in the form dimensions.

Open Access

Abstract

Seedling pecan tree [Carya illinoensis (Wangenh) C. Koch] roots were flooded for 28 days while trees were either dormant, beginning budbreak, or in active growth, plus an unflooded control. Flooding roots while trees were dormant did not affect growth and seldom affected leaf elemental concentrations compared to unflooded trees. Trees with roots flooded during budbreak usually had less leaf area and were shorter, with smaller trunks than unflooded trees. Leaf N and Fe concentrations were decreased immediately after flooding, but, 56 days after trees were drained, P, Ca, Mg, Zn, and Mn concentrations were greater than in unflooded trees. Leaf area, tree height, trunk diameter, and leaf and trunk dry weights were not affected by flooding during active growth. Root dry weight was reduced 31% immediately after trees were drained, and 48% 56 days after trees were drained compared to unflooded trees. Trees flooded during active growth had lower concentrations of N, P, K, Ca, Mg, Zn, Fe, and Mn immediately after flooding, but, 56 days after trees were drained, leaf elemental concentrations were not significantly different from unflooded trees.

Open Access

Abstract

The use of micro-computer programs as a management teaching aid has enabled horticulture students to understand economic relationships involved in the production of apples (2, 3), strawberries (4), and selected greenhouse crops (7). By incorporating uncertainty about final crop yield and selling price, these models can be used to generate information about the relative “riskiness” of crop production, where risk is measured by the probability that total revenue will exceed total costs (1, 8). The objective of this research was to develop a micro-computer model that would assist students and/or producers in understanding the economic relationships between yield and price variability and overall risk.

Open Access

Easter liliy (Lilium longiflorum Thunb. `Nellie White') bulbs were stored in moist peatmoss for up to 85 days at – 1.0 or 4.5C. Bulbs were periodically removed from storage and analyzed to determine levels of soluble carbohydrates and starch. Storage at – 1.0C induced large accumulations of sucrose, mannose, fructose, and oligosaccharide in both mother and daughter scales. Starch concentration declined substantially during this period. Storage at 4.5C resulted in less dramatic alterations in bulb carbohydrates, although trends toward increased soluble carbohydrates and reduced starch levels were seen. The accumulation of mannose suggests that glucomannan, a secondary storage carbohydrate, was also degraded during – 1.0C storage.

Free access

Plant Preservative Mixture™ (PPM), a relatively new, broad-spectrum preservative and biocide for use in plant tissue culture, was evaluated as an alternative to the use of conventional antibiotics and fungicides in plant tissue culture. Concentrations of 0.5 to 4.0 mL·L-1 were tested with leaf explants of chrysanthemum (Dendranthem×grandiflora Kitam), European birch (Betula pendula Roth), and rhododendron (Rhododendron catawbiense Michx.). PPM had little effect on the percentage of explants forming shoots and the number of shoots formed per explant in birch and rhododendron, but dramatically reduced both responses in chrysanthemum. Therefore, the effects of PPM must be evaluated for each species of interest prior to use.

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De-inked paper sludge from a newsprint mill was evaluated as a substitute for sofwood bark in container media. Rooted cuttings of `Youngstown' juniper (Juniperus horizonatlis), Fraser photinia (Photinia × fraseri), and `PJM' rhododendron (Rhododendron) were planted in 3-L plastic pots that contained potting media amended with 0%, 20%, 40%, 60%, 80%, or 90% paper sludge and 80%, 60%, 40%, 20%, or 0%, respectively, bark (by volume). All mixes contained 10% sand and 10% peatmoss except for the 90% mix, which lacked peatmoss. After 19 weeks, plant heights were measured for photinia and rhododendron, but average plant width was measured for juniper. Shoot dry weights were also determined for all species. Juniper and photinia seemed to be the most tolerant of media amended with up to 40% paper sludge, whereas rhododendron was the most intolerant species. Shoot dry weights of juniper or photinia were similar for plants grown in media containing 40% or less paper sludge. Shoot dry weights of rhododendron plants grown in 40% sludge were 23% lower than those grown in 0% or 20% paper sludge, which were similar to each other. Plant heights followed similar trends to those of the shoot dry weights. With the exception of juniper, shoot dry weights and heights were drastically reduced if the potting mixes contained more than 40% paper sludge. These results demonstrated that de-inked paper sludge could be substituted for up to 40% of the bark in a container medium for two of the three species tested.

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