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Submitted to: Journal of Small Fruit and Viticulture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/8/2002 Publication Date: 1/9/2003 Citation: Scagel, C.F. 2003. Mycorrhizal status of sand-based cranberry (Vaccinium macrocarpon) bogs in southern Oregon. Journal of Small Fruit and Viticulture. 2(1):31.41. Interpretive Summary: The current low-value of cranberry crops due to over-production is resulting in financial problems for growers. New uses for cranberry may eventually increase market demand however in the interim these producers need alternative strategies to increase crop value by filling specialty niches (e.g. organic production) and/or decreasing production costs by decreasing inputs (e.g. increasing nutrient use efficiency). Under field conditions in Southern Oregon we have found that the mycorrhizal infection of cultivated cranberry is low until bogs get over 10 years old. The level of cranberry root colonization by mycorrhizal fungi has implications to the efficiency of fertilizer uptake in both organic systems and conventional production systems and is an important factor to consider when assessing optimal cultural and fertilization practices for cranberry production. For instance, under organic production practices, organic forms of N are the primary form of N delivered to the plant. Under these conditions, plants without mycorrhizae must rely on the breakdown of this N by other soil microorganisms before the plant can take it up. Under conventional production practices, early colonization by mycorrhizal fungi may allow plants access to other sources of available N, thereby requiring less fertilizer N to achieve the same nitrogen concentration as non-mycorrhizal plants. Technical Abstract: Ericoid mycorrhizal fungi form symbiotic relationships with cranberry plants providing increased access to nutrients from fertilizers and soil. We conducted a survey assessing the mycorrhizal status of cranberry from bogs grown under conventional and organic production practices and ranging in age from two to thirty-eight years. We found root colonization increased dwith bog age regardless of production practices. Levels of root colonization on plants from bogs less than 10 years old were 7.5%,10 to 12 years old were 28%,15 to 21 years old were 70% and 32-38 were 90%. In contrast, root colonization on plants adjacent to the bogs showed colonization levels greater than 90%. This low colonization of cranberry in young bogs may have implications to fertilizer use in both organic and conventional production systems. For instance, under organic production practices, organic forms of N are the primary form of N delivered to the plant. Under these conditions, plants without mycorrhizae must rely on the breakdown of this N by other soil microorganisms before the plant can take it up. Under conventional production practices, early colonization by mycorrhizal fungi may allow plants access to other sources of available N, thereby requiring less fertilizer N to achieve the same nitrogen concentration as non-mycorrhizal plants. |
