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  • Author or Editor: D. J. Cotter x
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Abstract

One of paired tomato plants was sprayed with 100 ppm phenylmurcuric acetate (PMA). Transpiration rates were measured gravimetrically. During the initial daylight periods, PMA treatment reduced water losses in 2 tests. Conversely, night water losses were higher for the PMA treated plants in both tests. When moisture stress symptoms occurred, water losses by the treated plant were higher. The results indicate that PMA closes the stomates at some small aperature. This reduces transpiration when plants are not stressed for water. Relative increased water losses occur, however, when untreated plant losses would be minimal (dark, wilted).

Open Access

Abstract

Over two centuries ago Jonathan Swift wrote “necessity is the mother of invention.” Because the late Professor Emery Myers Emmert could not afford an expensive glass greenhouse, he invented the plastic greenhouse in 1948. It was covered with 4’ × 4’ wooden frames with supporting form wire (spaced every 6 inches) on which cellophane film was attached. These frames were nailed on the rafters of narrow wooden structures and lapped similarly to greenhouse glass. Remarkable as it now seems, he grew commercial crops of lettuce, tomatoes, and bedding plants in these houses for several years before the era of polyethylene.

Open Access
Authors: and

Abstract

Thirteen different foliar sprays and 1 soil treatment of several chemicals were evaluated for their effects on tipburn of ‘Great Lakes 659’ head lettuce. Succinic acid-2,2-dimethylhydrazide (5000 ppm), N-6 benzyladenine (25 ppm), simazine (2000 ppm), and 2-chloroethylphosphonic acid (100 ppm) plus CaCl2 (2500 ppm) each reduced tipburn. Triiodobenzoic acid (50 ppm) and phenylmercuric acetate (100 ppm) each increased tipburn, while gibberellic acid (50 ppm) plus N-6 benzyladenine (25 ppm), CaCl2 (2500 ppm), urea (2500 ppm), calcium chelate (100 ppm), and ethylenediaminetetraacetic acid (1 lb./acre) plus CaCl2 (100 lb./acre) soil treatment each had no significant effect on tipburn. Injury symptoms and reduced head weight were noted from simazine and phenylmercuric acetate treatments.

Open Access

Abstract

Experiments were conducted in 1979 and 1980 to evaluate anticrustant (H3PO4 and Nalco 2190) effects on stand establishment, growth, and yield of chile pepper (Capsicum annuum L.). While plant stands and fruit yield were not increased by applying H3PO4 over the seeded row in 1979, hypocotyl stress of germinants was reduced. Stands and P content in 1980 were not increased by H3PO4 or Nalco 2190 treatments 1 month after emergence, but plant height was increased significantly by both anticrustants. Yields of fresh green chile peppers were not enhanced by treatments. While germinant stress could be reduced by using anticrustants, it was concluded that a factor other than crusting was limiting chile seedling growth in southern New Mexico.

Open Access

Abstract

Plant dry weight of tomato (Lycopersicon esculentum Mill.) grown in aged bark media was equal to or greater than that of those cultured in a control medium of perlite-sand. Plant growth in fresh bark was inhibited initially and then recovered. Zn concentration and total content per plant were high for plants cultured in bark media even when little or no Zn was applied. The intereaction between media and applied Zn was significant. Plant Zn increased with increasing amount of applied soluble Zn when cultured in perlite-sand, but did not normally change for plants cultured in bark. High Zn concentration of plants cultured in fresh bark was too low to account for the initial growth inhibition. N concentration and content per plant were normally lower for plants grown in fresh bark. N of plants in aged bark was similar to plants in the standard medium. Growth inhibition of plants in fresh bark did not appear to be due to N deficiency.

Open Access
Authors: and

Abstract

Two jicama (Pachyrrhizus erosus Urban) or yam bean cultivars were grown for 0, 30, or 65 days of natural daylength prior to placement under short days (9-hour natural light, 0800 to 1700 hours) and long days (short day plus 87 watts/m2 incandescent light, from 2200 to 0200 hours). After 10 weeks, fleshy root growth was more rapid and extensive under short days for both cultivars in all pretreatment exposures. After 20 weeks, the relative differences in root dry weight were greater for 0- and 30-day pretreatment and in ‘Cristalina’ than in ‘Agua Dulce’.

Open Access