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ARS Home » Research » Publications at this Location » Publication #249277
Title: Organic tomato transplant production and supplemental fertilizers

Author
item Webber Iii, Charles
item ROBERTS, B - Oklahoma State Experiment Station

Submitted to: Extension Publications
Publication Type: Experiment Station
Publication Acceptance Date: 1/1/2010
Publication Date: 1/8/2010
Citation: Webber III, C.L., Roberts, B.W. 2010. Organic tomato transplant production and supplemental fertilizers. 2009 Vegetable Trial Report. Oklshoma State University, Division of Agricultural Sciences and natural Resources, Department of Horticulture and Landscape Architecture. Stillwater, OK. MP-164 p. 15-16.

Interpretive Summary: All components entering into the organic crop production system must be approved for organic use, including the seed, soil media, and fertilizer used in transplant production. Producing healthy transplants for organic production systems is an essential step in the process of maximizing crop yields. Research was conducted to determine whether addition of supplemental fertilizer to an organic soil medium enhances seedling growth. The factorial experiment included 4 fertilizer rates (5-4-4, 6-2-2, 7-3-7, and 0-0-0 N-P-K) added at 1% by weight prior to planting tomato (Solanum lycopersicon L.) seeds ('Florida 47') and 2 liquid fertilizer rates (0.4% and 0%) added at 3 weeks after planting (WAP) with 6 replications and 6 plants per replication. Adding fertilizer prior to planting produced significantly greater plant heights at 3 and 5 weeks (WAP) compared to the control (0-0-0). Although there were few height differences among 3 fertilizer treatments at 3 WAP, the addition of 0.4% solution of a fish and seaweed fertilizer at 3 WAP resulted in a significant height increase at 5 WAP for the 6-2-2 fertilizer treatment. To produce suitable tomato transplants supplemental fertilizer was required at a level of 1% by weight of a 6-2-2 N-P-K organic fertilizer, which was further enhanced by applying a 0.4% solution of a fish and seaweed fertilizer at 3 WAP. This research demonstrated the importance of adding supplemental fertilizer to soil medium to maximize seedling growth to produce quality transplants. Further research should investigate additional organic soil media, fertilizer sources and rates, and crops.

Technical Abstract: Producing healthy transplants for organic production systems is an essential step in the process of maximizing crop yields. All components entering into the organic crop production system must be approved for organic use, including the seed, soil media, and fertilizer used in transplant production. Research was conducted to determine whether addition of supplemental fertilizer to an organic soil medium enhances seedling growth. The factorial experiment included 4 fertilizer rates (5-4-4, 6-2-2, 7-3-7, and 0-0-0 N-P-K) added at 1% by weight prior to planting tomato (Solanum lycopersicon L.) seeds ('Florida 47') and 2 liquid fertilizer rates (0.4% and 0%) added at 3 weeks after planting (WAP) with 6 replications and 6 plants per replication. Adding fertilizer prior to planting produced significantly greater plant heights at 3 and 5 weeks (WAP) compared to the control (0-0-0). Although there were few height differences among 3 fertilizer treatments at 3 WAP, the addition of 0.4% solution of a fish and seaweed fertilizer at 3 WAP resulted in a significant height increase at 5 WAP for the 6-2-2 fertilizer treatment. To produce suitable tomato transplants supplemental fertilizer was required at a level of 1% by weight of a 6-2-2 N-P-K organic fertilizer, which was further enhanced by applying a 0.4% solution of a fish and seaweed fertilizer at 3 WAP. Further research should investigate additional organic soil media, fertilizer sources and rates, and crops.