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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #271454
Title: Irrigation frequency during container production alters Rhodendron growth, nutrient uptake, and flowering after transplanting into a landscape

Author
item Scagel, Carolyn
item BI, GUIHONG - Mississippi State University
item FUCHIGAMI, LESLIE - Oregon State University
item REGAN, RICHARD - Oregon State University

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2014
Publication Date: 7/1/2014
Citation: Scagel, C.F., Bi, G., Fuchigami, L.H., Regan, R.P. 2014. Irrigation frequency during container production alters Rhodendron growth, nutrient uptake, and flowering after transplanting into a landscape. HortScience. 49(7):955-960.

Interpretive Summary: The influence of irrigation frequency (same amount of water per day given at different times) and nitrogen (N) fertilizer application rate during container on nutrient uptake, growth, and flowering of evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ) was evaluated after 3 months after transplanting into a landscape the following year. More frequent irrigation in containers decreased growth, delayed flowering, and decreased uptake and use of many nutrients by AZ in the landscape. In contrast, more frequent irrigation increased growth, flower production, and uptake and use of many nutrients by PJM in the landscape. In ER, more frequent irrigation increased growth and uptake of most macronutrients, delayed flowering, produced smaller inflorescences, and decreased uptake and use of many micronutrients by ER in the landscape. Irrigation frequency in container production alters early-season performance of Rhododendron in the landscape through its effects on nutrient nutrient reserves; however, the effects of irrigation frequency on plant performance in the landscape was only partially attributable to it's influence on nutrient uptake.

Technical Abstract: The influence of irrigation frequency (same amount of water per day given at different times) and nitrogen (N) fertilizer application rate during container on nutrient uptake, growth (biomass) and flowering of evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ) was evaluated after 3 months after transplanting into a landscape the following year. More frequent irrigation in containers decreased growth, delayed flowering, and decreased uptake and use of many nutrients by AZ in the landscape. In contrast, more frequent irrigation increased growth, flower production, and uptake and use of many nutrients by PJM in the landscape. In ER, more frequent irrigation increased growth and uptake of most macronutrients, delayed flowering, produced smaller inflorescences, and decreased uptake and use of many micronutrients by ER in the landscape. Differences in nutrient uptake and use in the landscape were not complete attributable to differences in growth or nutrient uptake due to irrigation frequency in containers. Irrigation frequency altered aspects of plant quality that were not detectable by measurement of biomass in container production but were dateable in plant growth and flowering the following season. Early-season plant performance in the landscape is discussed in relationship to water and N availability during production and their effects on water stress, nutrient uptake, and biomass partitioning.