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  • Author or Editor: Robert S. Brown x
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`FTE 30' tomato (Lycopersicon esculentum) transplants were produced in Florida under standard commercial conditions and supplied with one of six treatments: zero, low (20% of the control rate), or high (control) super-phosphate (SP) fertilizer, or 0.5%, 1%, or 2% buffered-phosphorous fertilizer (Al-P). Growth characteristics were evaluated for four sets of transplants, produced in January, April, May, and August. Two sets of transplants were grown in the field in Florida (started in January and August) and one set was grown in Pennsylvania during the summer (started in May). Phosphorus concentration in leachate was measured weekly from one crop. Plants grown with Al-P showed a 72% to 88% reduction in P released in leachate compared with the high SP control. Transplants produced with 1% or 2% Al-P were of equal size and quality compared with transplants produced with conventional (high SP) fertilization, and had greater total root length and specific root length (length per unit root weight). Transplants grown with 0.5% Al-P were sometimes smaller than other fertilized treatments, while no-P plants were very small and grew slowly after transplanting. There were no significant differences in growth, yield, or fruit quality of plants fromtransplants grown with 1% or 2% Al-P or high SP at either site. Therefore high quality tomato transplants can be produced using buffered-P fertilizer, while reducing P leaching from the containers.

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Common bean (Phaseolus vulgaris L.) is a nutritionally complete food, but contains antinutritional compounds that reduce digestibility. One group of compounds includes the raffinose family oligosaccharides (RFOs) (raffinose, stachyose, and verbascose), which are partly responsible for flatulence after beans are eaten. RFOs stabilize cell membranes during seed desiccation and when the seed rehydrates during germination. While low levels of RFOs are desirable nutritionally, high levels may enhance germination and emergence, particularly in cold, wet soils. Eight landraces selected for high and low sucrose, raffinose, and stachyose content, were crossed in a diallel mating design to investigate genetic control of the RFOs. Derivatized soluble sugars were measured using gas-liquid chromatography. Fructose, sucrose, raffinose, and stachyose were detected. In the F1, fructose varied from 0.1 to 2.5 mg·g-1 dry weight (DW), sucrose from 17.2 to 56.5 mg·g-1 DW, raffinose from 0.1 to 4.1 mg·g-1 DW, and stachyose ranged from 7.6 to 43.7 mg·g-1 DW. Griffing's analysis estimates of general combining ability were on average, 16.5 times larger than specific combining ability for all the RFOs, indicating that additive genetic variance was most important. Significant reciprocal differences were detected in the F1 and F2, but not in the F3. RFO accumulation was partially dominant as indicated by Hayman's analysis. Narrow sense heritability averaged over F2 and F3 generations for sucrose, raffinose, stachyose, total sugar, and total oligosaccharides were 0.22, 0.54, 0.44, 0.17, and 0.27, respectively. Moderate heritabilities indicate that manipulation of RFO accumulation in this set of bean lines would probably need to be done on a progeny row basis with replication.

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Abstract

Topped 1- and 2-year-old seedlings of silver maple (Acer saccharinum L.), American sycamore (Platanus occidentalis L.), cottonwood (Populus deltoides Marsh.) and American elm (Ulmus americana L.) were treated with each of 10 growth regulating chemicals in the greenhouse by chemical injection. Daminozide [butanedioic acid mono (2,2-dimethylhydrazide], maleic hydrazide [l,2-dihydro-3,6 pyridazinedione] and the soldium salt of dikegulac [2,3:4,6-bis-0-(l-methyl-ethylidene)-L-xylo-2-hexulofuranosonic acid] controlled regrowth at appropriate concentrations without causing unacceptable phytotoxicity.

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