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  • Author or Editor: Ronald H. Walser x
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Abstract

The promotion of adventitious root formation by paclobutrazol was tested by placing cuttings in solutions of the chemical for 24–40 hr, and then observing the rooting response. Paclobutrazol at relatively low concentrations (3 to 6 mg·liter-1) increased the number of roots formed on cuttings of Creeping Charlie (Plectranthus australis R. Br.) and common bean (Phaseolus vulgaris L.) by about 100% and 85%, respectively. Paclobutrazol did not affect root length greatly but reduced shoot length by about 20% compared to controls.

Open Access

Seeds of Lycopersicon esculentum Mill. cv. UC 82L were treated with hypertonic priming solutions containing KNO3 and K3PO4(10 g·liter-1 each), and various concentrations of uniconazole before sowing. Treatment of the seed with priming solution only hastened emergence by ≈ 2 days compared to untreated seed sown directly from the packet, but did not affect total emergence after 12 days. Addition of uniconazole to the priming solution had no significant effect on speed of emergence or total emergence after 12 days compared to the primed control. Seed priming plus uniconazole at 1 or 10 mg·liter-1 reduced seedling height after 2 weeks by ≈ 20% compared to the primed control. Uniconazole had no effect on the mortality of either hardened or nonhardened seedlings exposed to below-freezing temperatures for 3 hr. These data suggest that treatment of tomato seed with hypertonic solutions containing uniconazole would be of little practical value in protecting seedlings from freeze damage. Chemical names used: (E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-yl)penten-3-ol (uniconazole).

Free access

Abstract

Severely chlorotic ‘Delicious’ apple (Malus domestica Borkh.) trees growing in a calcareous soil were pressure-injected with a 1.0% (w/w) ferrous sulfate solution. Net photosynthesis (Pn) of iron-treated trees was at least 50% greater than controls within 10 days after injection and reached as high as 115% above controls during the first growing season. Chlorophyll (Chl) concentration closely paralleled Pn during the first growing season, but the correlation was not as strong thereafter. During the 3rd growing season after injection, Pn of injected trees declined, yet still remained greater than controls until September (last sampling date). Visual chlorosis reappeared in the young terminal leaves near the end of the 3rd growing season. Stomatal diffusive resistance was unaffected by the treatments. Foliar iron concentrations in treated trees increased above the controls for about 2 months after injection. Thereafter, foliar iron content gradually decreased until the end of the first growing season, after which concentrations were similar to controls. Results indicate that injection of iron into chlorotic apple trees can enhance Pn and Chl for at least 3 growing seasons.

Open Access

Abstract

Severely chlorotic ‘Red Delicious’ apple (Malus domestica Borkh.) trees growing on a calcareous soil were treated for iron (Fe) chlorosis with pressure injections of 1.0% (w:w) solutions of ferrous sulfate, ferric citrate, or Fe-Sequestrene-330 (Fe-330). Injections were made in September of 1981 and in April, June, and July of 1983. All treatments increased chlorophyll concentrations compared to controls, and treatments made in September of 1981 and in April and June of 1983 increased shoot growth during the 1983 growing season compared to controls. Although the treatments did result in a temporary increase in foliar Fe content, there was not a strong correlation between foliar Fe and chlorophyll concentration. Ferrous sulfate and Fe-330 were more effective than ferric citrate in alleviating chlorosis. Injections made in April and June of 1983 greatly increased bloom in May of 1984, compared to trees injected in July of 1983 and the untreated controls. Hence, injections should be made early in the season (before July) in order to promote bloom the following growing season.

Open Access

Abstract

A 2-year study involving 15 garden vegetables and 5 different-sized gardens was conducted to assess land, labor, and production efficiency. As garden size increased, total production increased, but yield per unit area decreased. Relative labor inputs varied with garden size, but were greatest for harvesting (38%) followed by planting (23%), miscellaneous (22%), and weeding (17%). The highest production in relationship to labor and land use was obtained with beets, carrots, cucumbers, onions, tomatoes, and summer squash. The poorest yielding crops were pole and bush beans, sweet corn, peas, peppers, and radishes. Total vegetable yield for the 2-year study averaged 6.2 kg/m2.

Open Access