Domestication of “Deguai” (Saurauia bontocensis Merr.) at La Trinidad, Benguet, Philippines

Abstract

“Deguai” (Saurauia bontocensis Merr.) is an indigenous wild fruit-bearing tree in the Cordillera Administrative Region (CAR), Philippines. Due to rampant and continuing conversion of its habitat into agricultural and other uses, its population has become low, and its distribution has narrowed considerably. Thus, conserving and domesticating this endemic species by establishing propagation techniques and mini-tree plantations is timely and crucial. Results showed that deguai could be readily raised by sowing fresh seeds in heat-sterilized loam soil without pre-germination treatments. It took 22 d from sowing to start and 48 d to end the germination, with a mean germination percentage of 39.60. Moreover, transplanted seedlings in various media combinations showed significant growth differences in root collar diameter (RCD) and length of primary and secondary roots but not on their height and number of secondary roots. Compost in combination with either topsoil or sand significantly emerged as the most suitable media for the growth of the studied seedlings. Stem cuttings grew best untreated rather than applying rooting hormones such as alpha-naphthalene acetic acid (ANAA) and Hormex. This result was manifested in the significantly high survival rate, numerous developed buds, and longest newly developed shoots of untreated cuttings. Stem cutting section treatment significantly affected the number of developed buds only, where base cuttings had the most. The mini-tree plantation established using rooted stem cuttings was successful with a high survival rate of 89.26% after 5 yr from field planting and with four deguai trees bearing fruits for the first time after 7 yr from field planting. The nursery-grown seedlings planted in the mini-tree plantation have exhibited a 99% survival rate nine months after outplanting. Thus, deguai can be domesticated in the new habitat for fruit production, improvement of the environment, and biodiversity conservation. Monitoring of the trees continues, and a study toward generating a fruit production-enhancing technique for the species is readied for implementation.