ISHS Acta Horticulturae 797: International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions
TOMATO SEED GERMINATION IN ORGANIC MIXES: ROLE OF EC AND MIX COMPONENTS |
| Authors: | M.M. Peet, E.S. Larrea, C. Harlow |
| Keywords: | germination, sustainable, compost, vermicompost, EC, feathermeal, kelp meal |
| DOI: | 10.17660/ActaHortic.2008.797.56 |
| Abstract:
Organic production is an increasing segment of the produce market. The US National Organic Program (NOP) requires organically grown transplants. Commercial availability of certified vegetable transplants is limited, especially for small, diversified growers, so transplants are often produced on-farm. Commercial substrates for NOP-certified production may not be locally available or affordable, and have not been evaluated to the same extent as conventional substrates. The purpose of this study was to compare tomato seed germination in commercial organic and conventional substrates with each other and with a mix adapted from a local organic grower in 3 experiments. Tomato seedling germination in the grower mix, which contained vermicompost, feathermeal and kelp, was reduced compared to the conventional mix and three commercial organic mixes. To determine the role of mix components, germination was tested at lower rates of vermicompost and with components omitted. Initial mix EC levels were also tested using the Pour-Thru method. Overall, highest and most consistent germination was seen in the commercial conventional mix and the commercial organic mix with the lowest initial EC in the root zone. However, there was considerable variability and over the 3 experiments and 10 substrate formulations and it was difficult to correlate any one specific characteristic with germination. In conclusion, growers can achieve satisfactory results with a wide variety of organic substrates, both commercial and formulated on-farm. However, for mixes containing organic components, such as composts, which can vary from batch to batch, preliminary germination testing and adaptation of watering and other transplant production practices to the mix being utilized are advisable. | |
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