GROWTH OF ANNUAL PLANT SPECIES IN GROUND PROCESSED RICE HULL PRODUCTS

Pepper (Capsicum annuum) and impatiens (Impatiens walleriana) plants were grown in substrates composed of 20% perlite and 20%, 40%, 60% or 80% of a coarse, medium or fine grind of fresh rice hulls with the remainder being Sphagnum peat. Impatiens grown in substrates containing 40% of a coarse, medium or fine and 80% of a fine grind of rice hulls had similar shoot dry weights as those grown in a substrate containing 80% peat. Only impatiens grown in a root substrate containing 40% of the coarse grind of fresh rice hulls had lower root dry weight than those grown in substrates containing 80% peat. Peppers grown in a substrate containing 60% and 80% of a coarse, 60% of a medium or 60% and 80% of a fine grind of fresh rice hulls had similar shoot dry weights as those grown in a substrate containing 80% peat. There were no significant differences in pepper root dry weights among the substrates. Impatiens and pepper plants grown in a substrate containing 80% of the fine grind of fresh rice hulls were similar to those grown in 80% peat, and therefore, the fine grind of fresh rice hulls served as a suitable substitute for Sphagnum peat.