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  • Author or Editor: J. L. Weigle x
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Abstract

Considerable differences exist in the tolerances of onion inbreds to CIPC. Inbreds derived from ‘Iowa Yellow Globe’ were the most tolerant among the inbreds evaluated. Seedlings grown in the laboratory on agar containing the herbicide responded similarly to treated plants in field plots. The laboratory technique provides a fast, efficient method of screening large numbers of inbreds under controlled conditions.

Open Access

Abstract

Superimposed Amplified Exotherm Differential Thermal Analysis System is presented as a system used for detecting low-temperature exotherms of excised dormant flower buds. This system uses thermistors that do not penetrate the tissue and a liquid freezing medium for more uniform temperatures between the sample and reference. A test chamber is presented that can be used with a nonprogrammable freezer. Tests with Forsythia flower buds indicate 2 exotherms, the second of which is associated with a dramatic loss of tissue viability.

Open Access

Abstract

‘Blue Moon’ is a new cultivar developed from the New Guinea-type Impatiens collected by the U. S. Plant Introduction Service in 1970 (1). It is distinguished by large, bright, and abundant flowering and was selected for use as a bedding plant as were other Iowa State F1 hybrid releases (2).

Open Access

Abstract

The bright, deep-orange flowers and compact plant habit of Tropical Sunset’ suggest it as a replacement for Orange Chiffon’, an Iowa State F1 hybrid Impatiens released previously (2). This cultivar should make an excellent border planting for any landscape area not exposed to the midday sun.

Open Access
Authors: and

Abstract

Male sterility, of a cytoplasmic-generic nature, has been utilized in die production of commercial onion hybrids for a number of years. This procedure requires the time-consuming technique of introduction of male sterility control factors into inbreds before testing and the added cost of maintainer lines for production of male sterile inbreds. Chemical induction of male sterility would circumvent both of these requirements.

Open Access
Authors: and

Abstract

A range in flowering pattern from spring flowering only to continuous flowering was found among Weigela cultivars and seedlings. They also varied in flowering intensity from none to complete coverage of the bush. A positive relationship was found between the floriferousness of a parent and the percentage of its progeny that flowered during the first growing season.

Open Access

Abstract

In vitro propagation of induced tetraploid Java (J) Impatiens platypetala Lindl. TR6-19, New Guinea (NG) Impatiens sp. ‘Skyrocket’, and 2 interspecific J x NG hybrids, T63-1 and T63-3, was achieved by culturing shoot tips on agar-solidified MS revised medium supplemented with levels of kinetin and NAA. The mean number of shoots per shoot tip increased linearly from 0.3 shoots at 1.39 µM to 8.5 shoots at 139.0 µM kinetin for T63-1, the most responsive genotype. The number of shoots produced by T63-1 and T63-3 were not significantly different, but both hybrids produced significantly more shoots than either ‘Skyrocket’ or TR6-19. Shoot tips produced in vitro rooted readily and were transferred successfully to soil. Chemical name used: 1-naphthaleneacetic acid (NAA).

Open Access

Abstract

Experimental techniques are described for concentric circular test patterns with intentional exposure to a 2,4-D source at the center. With the intensity of exposure as a function of distance from the center, various degrees and symptoms of expression of 2,4-D damage were obtained for a wide variety of horticultural plants. Observations were made on overwintering damage, carry-over effects on potted specimens returned to the greenhouse, seed carry-over effects (none), and effects on virus-infected plants.

Open Access

Abstract

Crops were grown in field plots under plastic-covered greenhouses for 3 years under ambient, charcoal-filtered, and charcoal-filtered with 2,4-D added atmospheres. No differences in market quality were found with green beans and raspberries. Deformed fruit in strawberries, uneven berry ripening in grapes, and blotchy ripening and deformed fruit in tomatoes occurred in “2,4-D added” treatment but not in “charcoal-filtered” treatment, while “ambient” was generally intermediate. The amount of 2,4–D in the atmosphere also influenced yields of grapes and strawberries.

Open Access

Abstract

‘Burgundy’ joins the previously released Iowa State F1 hybrid Impatiens (2) in its ability to withstand the rigors of the U.S. Midwest environment while making a colorful addition to the world of bedding plants. ‘Burgundy’ was derived from plant material obtained by the U.S. Plant Introduction Service from New Guinea and nearby islands in 1970(1).

Open Access