Mary Ann Rose and Barbara Biernacka
The Ohio State University Department of Horticulture and Crop Science
In Press. HortScience.
Abstract. Seasonal patterns of N, P, and K accumulation and remobilization in Freeman maple (Acer x freemanii E. Murr. 'Jeffersred') were studied to guide future improvements in fertilization efficiency. Leaves, stems, and roots of container-grown trees were harvested over a 12-month period (June-June) in each of two experiments. Plants were fertilized from June to October with three rates of soluble fertilizer (50, 100, and 200 mg.L-1 N). Fertilizer rate had linear and quadratic effects on dry weight and nutrient contents but did not affect seasonal accumulation patterns. Whole-plant nutrient contents and dry weights increased until mid-October, prior to leaf abscission. The largest fraction of nutrients and dry weights were allocated to leaves until early September. Between September and October, the most rapid accumulation of N, P, and dry weight occurred in root tissue. Highest nitrogen recovery efficiency occurred in late summer (Experiment 2) or early fall (Experiment 1). There was no statistically significant evidence for N, P, or K resorption in the fall, but evidence of N remobilization (not P or K) in the spring was very strong. Whole-plant dry weight doubled between April and June, while ~50% of the N stored in woody tissues was translocated to new shoots.
Mary Ann Rose and Hao Wang
The Ohio State University Department of Horticulture and Crop Science
In Press. HortTechnology.
Mary Ann Rose and Hao Wang
The Ohio State University Department of Horticulture and Crop Science
In Press. HortScience.
Abstract. Crabapple [Malus x zumi (Rehd.) 'Calocarpa'] and maple (Acer x freemanii E. Murray 'Jeffersred') trees were grown in containers from June 22 to Oct. 3 with three fertilizer concentrations (50, 100, and 200 mg.L-1 N) and two levels of moisture tension in the medium [low setpoint (moist) = 5 kPa and high setpoint (dry) = 18 kPa]. Whole-plant growth was enhanced more by minimizing water stress than by increasing fertilizer concentration. Shoot length and whole-plant dry weight were greater (> 29% for crabapple and > 90% for maple) in low-tension treatments (low water stress) but were unaffected by fertilizer concentration. Moisture tension also had a dominant effect on dry weight allocation to leaves, stems, and roots. In contrast, foliar nutrient concentrations increased with fertilizer concentration but were affected to a lesser degree by moisture tension. Seasonal patterns in biomass allocation were little affected by treatments; the largest proportions of leaf and root biomass accumulated during summer and fall, respectively.
Margaret McMahon
The Ohio State University
In press. Scientia Hort.
Abstract. 'Spears' chrysanthemums (Dendranthema x grandiflorum [Ramat.] Kitamura) were grown under solar filters filled with CuSO4 in solution which absorbs far-red (FR), or water, which does not absorb FR, and were exposed to marginally long natural photoperiods, artificially long photoperiods, or artificially short photoperiods. Internode length and plant height were reduced under CuSO4 filters compared to plants grown under water filters, regardless of photoperiod. Plants grown under water- or CuSO4-filled filters that received artificial short days flowered seven days ahead of plants grown in natural, marginally long photoperiods under CuSO4 filters and 17 days ahead of plants grown under water filters and receiving natural, marginally long photoperiods. The number of nodes was the same for plants grown in short and marginally long days under CuSO4 filters and in short days under water filters, indicating flower induction occurred simultaneously in these treatments. Development of additional nodes on plants under water-filled filters and receiving natural long-days indicated that floral induction was delayed. A cool white fluorescent light night break prevented or delayed flowering of plants grown under water- and CuSO4-filled filters during natural short days. The results demonstrate that standard practices of photoperiodic control can be used to time chrysanthemums 'Spears' grown under CuSO4 filters for pot mum production.
M. J. McMahon
The Ohio State University
J. W. Kelly
Clemson University
Plant Growth Reg. Soc. Quarterly
Abstract. Plants of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) 'Glory' were grown in chambers fitted with double-walled polycarbonate panels filled with light-filtering solutions of a blue dye, a 6% (w:v) CuSO4 . 5H2O, and water (control) that altered the ratio of red (R) to far-red (FR) light to 1.00, 3.33, and 1.16, respectively. Plants grown under CuSO4-filters were shorter (32%) with shorter internodes (48%) than control plants. Leaf chlorophyll was 56% greater in CuSO4-grown plants compared to control. Plants from all treatments flowered at the same time when placed in the chambers during inductive short-day photoperiods (year one). Plants flowered two weeks earlier under CuSO4 filters compared to controls when placed in the chambers during noninductive photoperiods (year two). Far-red-absorbing filters have the potential to become a useful plant growth tool.
Cassandra C. Brown and Mary Ann Rose
The Ohio State University Department of Horticulture and Crop Science
Expanding urbanization in Ohio has made the availability of quality water an emerging issue of great importance to the state's nursery industry. This development necessitates an examination of nurseries' use and management of water. This study surveyed 600 Ohio nursery growers with a mail questionnaire to determine the frequency of irrigation and water-saving techniques across the state. The 21-question questionnaire covered topics including water sources, irrigation practices, water testing, and information needs. The mailing list used was the Ohio Department of Agricul-ture's licensed nursery operators list. Non-respondents received a postcard reminder and a second copy of the survey within three months of the initial mailing, yielding a 45% response rate. Data were analyzed using SPSS software. Responses indicate that approximately 57% of Ohio nurseries used irrigation in the 1997 growing season. For field production, 64% of nurseries used overhead irrigation for at least half of their irrigated production; for container production, 91%. Nearly 41% of respondents using irrigation reported capturing runoff for reuse this past year. The most common irrigation sources for Ohio nurseries were wells (79%) and ponds (62%). Additional goals for the project included raising awareness of water-management and water-quality issues, identifying common water-quality problems, and obtaining direction for future research and extension efforts.