2017 ASHS Annual Conference

Native and endemic Peperomia species found in Hawaii have high indoor ornamental potential due to their compact growth and attractive foliage. To evaluate their potential use as houseplants, methods to mass propagate plants must be researched and developed. The use of whole-leaf cuttings and rooting hormone applications are established methods that may be useful for propagating Hawaiian Peperomia species. Studies were conducted to evaluate the rooting response of Hawaiian Peperomia leaf cuttings treated with or without indolebutyric acid (IBA). Whole leaf cuttings (10 leaves per replicate) of P. leptostachya, P. cookiana, P. oahuense, and P. sandwicensis were harvested, sorted by size classes, and treated with or without 1000 ppm IBA. P. leptostachya leaf cuttings were planted in plastic pots (n=5) with a 1:1 by volume mix of perlite:peat moss. Leaf cuttings of P. cookiana, P. oahuense, and P. sandwicensis were planted in plastic pots (n=4) filled with a 1:1 by volume mix of perlite:vermiculite. P. leptostachya cuttings were rooted under 80% shade and sprinkler irrigation (twice a day for 10 minutes), whereas P. cookiana, P. oahuense, and P. sandwicensis cuttings were rooted on a shaded mist bench (misting for 15 seconds every five minutes). Percent rooting and length of the longest root were collected 30 days after planting (DAP) for P. leptostachya, 41 DAP for P. cookiana, 34 DAP for P. sandwicensis, and 34 DAP for P. oahuense. Rooting characteristics of all species did not show significant differences between treated and untreated leaf cuttings. Percent rooting of P. leptostachya, P. cookiana, and P. oahuense leaf cuttings were above 84%, whereas P. sandwicensis leaf cuttings exhibited 10% rooting. Average length of the longest root was 2.2 cm for P. leptostachya, 1.97 cm for P. cookiana, 2.11 cm for P. oahuense, and 0.70 cm for P. sandwicensis. Leaf rot, which resulted in the low percent rooting of P. sandwicensis, may have been due to conditions being too wet for rooting. Further evaluation of this species at lower mist frequencies is recommended. Results of the studies indicate that leaf cuttings can be a viable propagation method for P. leptostachya, P. cookiana, P. oahuense, and P. sandwicensis.