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  • Author or Editor: David R. Hershey x
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Abstract

Shoot or leaf cuttings can be rooted in flats of perlite under intermittent mist for use in a static solution culture system (Hershey and Merritt, 1986). However, removing perlite from the roots before transfer to hydroponics is tedious and damages the roots; also, all the perlite cannot be removed, which causes errors in dry mass and nutrient concentration determinations. A hydroponic propagation system was constructed of inexpensive, readily available materials that allowed rooting of large numbers of cuttings under intermittent mist.

Open Access

Abstract

Electrical conductivity (EC) measurement is widely used in horticulture to estimate salinity and fertilizer levels in irrigation waters, nutrient solutions, soils, and growing media (1–4). EC often is referred to as specific conductance (5), conductivity (1), or soluble salts; however, the term EC has been used widely in scientific literature (2–4).

Open Access

Abstract

The pH of a plant growing medium is a major determinant of nutrient availability and plant growth (1), so monitoring the pH of growing media is an important management practice. The pH of growing media can be measured colorimetrically with test papers or indicator solutions (2, 4) or potentiometrically with a glass electrode pH meter (1, 2, 6). Colorblind people, estimated to be 10% of the male population, cannot use colorimetric methods (3).

Open Access

Abstract

Probe pH meters are marketed by many horticultural suppliers and cost from $5 to $21. A probe pH meter consists of an analog meter attached to one or two metal probes. To measure pH a probe is pushed into moist growing medium, and the indicator needle points to the pH. Despite low cost and seemingly simple operation, probe pH meters have been criticized as being unsuitable for horticultural use (1, 3). I, therefore, evaluated the accuracy of a probe pH meter for measuring growing media pH.

Open Access

Abstract

One of the most important aspects of the physics of growing media in containers is the limited bulk volume of the medium (2,4). Bulk volume (BV) includes the volume of the medium solids and pore spaces (1). Despite the importance of BV in determining the amounts of air, water, and nutrients in the pot, BV is rarely specified in research articles involving plant growth in container media. Without BV, volumetric properties, such as bulk density (g/ml), container capacity (percent by volume), air-filled porosity (percent by volume) and fertilization and liming rates (kg/m3), cannot be converted to absolute amounts per pot. The purpose of this study was to develop equations to calculate BV using pot dimensions and medium height in the pot.

Open Access

Abstract

ASHS specifies that minimum heights for poster lettering be 25 mm for the titles, authors, and institutions and 12.5 mm for everything else (ASHS, 1988). A survey of 167 posters in Poster Session 1 at the 1988 Annual Meeting indicated that these required minimum lettering sizes are usually not met (Table 1). One reason why these minimums are rarely met is that the minimum heights are unrealistic. The minimum heights were established for 2.4 × 1.2-m posters and not reduced when poster area was halved to 1.2 by 1.2 m. The 1:1 ratio between title and author/institution letter heights is not proportional because title lettering is nearly always taller than author/institution lettering. For example, HortScience titles are 5 mm tall with author/institution lettering 2.5 mm high. Thus, the smaller lettering for authors/institutions compared to titles on ASHS posters is understandable.

Open Access

Abstract

Byrne (1988) discussed the confusion between the words “pollenizer” and “pollinator”. A mnemonic device to remember the difference between the terms is to associate the “t” in pollinator with the word “transfer”, since the definition of pollinator is “the agent of pollen transfer” (Byrne, 1988).

Open Access

Abstract

As horticultural scientists, we are greatly concerned with numbers—the number of refereed articles we can publish, the number of research grant dollars we can obtain, the number of people served by our extension programs, and the number of students enrolled in our horticultural curricula. One number that we do not usually consider is the distribution number for the horticultural periodicals in which we publish.

Open Access

Abstract

It is hoped that Science Editor Lipton’s opinion [ASHS Newsletter 5(2):1–2] that horticultural research publications are free of fraud is correct, as fraud is typically very difficult to prove and there are considerable pressures to “publish or perish”, even in horticulture. Unfortunately, a type of fraud seems widespread in commercial horticulture in the form of “miraculous” claims for horticultural products, such as fertilizers and biocatalysts. This type of fraud reflects badly on horticultural science; therefore, horticultural scientists have a duty to conduct research that tests such claims.

Open Access