Coconut Coir Medium for Tomato Transplant Production

Abstract

Peat [70% peat + 30% vermiculite (v/v/)] has long been the primary growing medium in standard vegetable transplant production. However, interest has increased in the use of coir (coconut pith) as an alternative vegetable transplant medium because of favorable physico-chemical properties such us high water holding capacity, low bulk density and high potassium content. Sixteen different transplant media formulations (v/v) were tested in a mixture component experiment with tomato, using coir and peat as organic components and vermiculite and perlite as inorganic components. Transplant growth was evaluated after 4, 5, and 6 weeks by growth analysis and at 6 weeks transplant quality parameters (e.g. shoot/root dry weight, leaf area, stem diameter, height, etc.) were collected. Coir grown tomato plants showed a delay in leaf production exhibiting lower leaf area values over the total transplant growth period. Shoot and root growth was maximized in media containing peat as the major organic component. However, plants grown in a 50% peat/50% vermiculite medium were too tall for commercial acceptance. Plants grown in all sixteen-transplant media pulled easily. However, medium loss when transplants were pulled was unacceptable in medium high in perlite content (50% by total volume). Coir-medium compared well with the standard peat/vermiculite medium based on the transplant quality parameters of stem diameter, root growth and height when used in the following mixtures: 50% peat/25% coir/25% vermiculite and 50% peat/25% coir/25% perlite.