Coir as an alternative to peat in media for tomato transplant production

Sixteen media prepared front peat, coir, vermiculite, or perlite were used to determine the optimum growing media for tomato (Lycopersicum esculentum Mill.) transplants. Medium composition did not affect tomato seed emergence, although seedling emergence was higher in winter (90%) than summer (85%). Greatest transplant root dry weight, stem diameter, and leaf area were achieved in 50% to 75% peat + 25% to 50% vermiculite in summer. In winter, greatest transplant root dry weight, stem diameter, and leaf area were achieved in eight media: 100% peat, 75 % peat + 25 % vermiculite, 75 % peat + 25 % perlite, 50% peat + 50 % vermiculite, 50 % peat + 50% perlite, 25% peat + 50 % coir + 25% vermiculite, 50% peat + 25% coir + 25% vermiculite, and 25% peat +25% coir +25% vermiculite +25% perlite. Transplants grown with >50% coir exhibited reduce plant growth compared to peat-grown transplants, a response that may be associated wit high N immobilization by microorganisms and high C:N ratio. Despite transplant growth differences during the summer, fruit yields generally were unaffected by transplant media.