, the Trans-Pecos in western Texas, and the High Plains in northern Texas ( Hall et al., 2000 ). Their recommendations for sowing dates extend from October to March, with short-day, intermediate-day, and long-day onion varieties, depending on the region
George E. Boyhan, Juan Carlos Diaz-Perez, Chris Hopkins, Reid L. Torrance and C. Randy Hill
Fumiomi Takeda, D. Michael Glenn and Gary W. Stutte
The fall-to-winter strawberry production system in the mid-Atlantic coast region combines the new technologies for containerized nursery (plug) plant production with the protected culture system ( Takeda, 1999 ). Short-day strawberry cultivars
Ryan M. Warner
great variability in the number of photoinductive cycles necessary to induce flowering among photoperiodic plant species. Some species, including the short-day plants Pharbitis nil ‘Violet’ Chois., Chenopodium rubrum L., and Xanthium strumarium L
George E. Boyhan, Ray J. Hicks, Reid L. Torrance, Cliff M. Riner and C. Randell Hill
Onions are an important crop grown on 15,000 acres in southeastern Georgia with over a $125 million value ( Boatright and McKissick, 2006 ). Mild short-day onions known as Vidalia onions are the number one vegetable crop in the state by crop value
Theodore J. Kisha and Christopher S. Cramer
across the genome of interest ( van Treuren and van Hintum, 2009 ). A recently conducted, short-day onion germplasm plant exploration resulted in the collection of 70 to 75 lines that may be included in the onion collection to expand the number of short-day
Daedre S. Craig and Erik S. Runkle
duration of the dark period, also known as the critical night length ( Thomas and Vince-Prue, 1997 ). Plants have been classified into photoperiodic response groups depending on how the critical night length influences flowering. Short-day plants (SDPs
George E. Boyhan, Reid L. Torrance and C. Randy Hill
fertility. Increasing N levels in hydroponic production of short-day onions has resulted in increased pyruvate, which is an indicator of pungency ( Coolong and Randle, 2003 ). Phosphorus (P) requirements and utilization in onions has also been extensively
George E. Boyhan, William M. Randle, Albert C. Purvis, Pamela M. Lewis, Donna O. Linton, Reid L. Torrance and David E. Curry
A 3-year study on the effects of growth stimulants on yield, bulb size, bulb quality, and storability of short-day onions (Allium cepa L.) was conducted at three locations. Treatments included 2-hydroxypropanoic acid, humic acids, humic acids in conjunction with micronutrients, and two formulations of cytokinin applied as a transplant dip and/or plant spray. There were no differences between 2-hydroxypropanoic acid and an untreated check at two different farm locations for onion yield, equatorial bulb diameter, or percent jumbos [≥3 inches (≥7.6 cm)] in 1997. Comparisons between untreated checks, 2-hydroxypropanoic acid, humic acids as a transplant dip or plant spray, and humic acids with micronutrients, all applied as transplant dip or plant spray, indicated there were no differences among treatments for yield, pungency, soluble solids, equatorial bulb diameter, or percent marketable bulbs after 6 months in controlled atmosphere storage in 1997-98. In a final experiment, these treatments were evaluated in a factorial arrangement using the short-day onion cultivar Pegasus and a mixture of cultivars WI-609 and WI-3115, which are referred to as Wannamaker cultivar mix. `Pegasus' displayed higher yield and lower soluble solids than the Wannamaker cultivar mix. Treatment with humic acids and micronutrients, or cytokinins resulted in greater percent marketable bulbs after 4.5 months of controlled atmosphere storage compared to the untreated check. No differences were observed among the treatments for pungency or bulb size. In addition, there was no treatment by cultivar interaction.
William M. Randle
Sulfur fertility influences flavor in onions. To determine how sulfur is utilized by onions over the course of growth and development, five short-day onion (Allium cepa L.) cultivars were grown at high (4.0 mequiv.liter-1) and low (0.1 mequiv. liter-1) sulfur fertility regimes under greenhouse conditions. Plants were measured for foliar sulfur content at 4 week intervals during the course of the growing season and for bulb sulfur and pyruvic acid development at plant maturity. Patterns of sulfur uptake and utilization were similar for all five cultivars but cultivars differed in their magnitude of sulfur accumulation. Foliar sulfur accumulation correlated poorly with bulb sulfur and pyruvic acid development at all sampling dates.
F.J. Bigras and A.L. D'Aoust
Seventeen weeks old white spruce seedlings were hardened under 8 h or 16 h photoperiod for 28 d at 15°C (12 h) followed by 21 d at 3°C (8 h photoperiod) and 28 d at 0°C without light. Dehardening conditions were a 14 h photoperiod at 10°C for 21 d followed by 18 d at 20°C. Frost tolerance of whole plants and exised organs were measured at regular intervals. An earlier rehardening was observed for plants hardened under short day treatments. Similar results have been reported for black spruce in independant studies. Hypotheses to explain this phenomenon will be presented based on bud phenology, mineral content, sugar analyses and morphological data.