Hawai'i conservation alliance

2008 Runner Up Student Poster Presentation

The Response of Fimbristylis cymosa R. Br. to Three Methods of Hydroplanting

Orville Baldos, Joseph DeFrank
University of Hawai‘i at Mānoa, Honolulu, Hawai‘i, United States

Establishing native species on any roadside re-vegetation project requires proper species selection and planting techniques. Hydroplanting is a well established method of large-scale planting which involves the application of seeds, sprigs or stolons via a water jet. This technology, used to stabilize steep slopes and establish turfgrass in residential areas, is being developed for roadside establishment of native Hawaiian species. In this study, three aspects of hydroplanting Fimbristylis cymosa were assessed on compost filled plots (9.3 m2). Treatments consisted of the following: hand sown two month old seedlings (199 plants/m2) covered with hydromulch (4400 kg paper mulch/ha); hydroseeding (a mix of seed and hydromulch applied at a rate of 481 seeds/m2 and 2200 kg paper mulch/ha); and a hydroplanted mix of two month old seedlings (199 plants/m2) and hydromulch (4400 kg paper mulch/ha). The hydroplanting system used to apply the treatments consisted of a 190 liter tank connected a centrifugal pump applying approximately 114 liters per minute. Data collected included plant counts for the first two months and percent visual cover for the first six months. Hydroseeded treatments exhibited the highest plant number and percent visual cover over the six month period. Plantlets covered with hydromulch did not significantly differ with hydroseeding in terms of percent visual cover. Low plant counts and percent visual cover observed in the hydroplanted seedling-mulch mix was due to mechanical damage incurred as seedlings passed through the centrifugal pump. These data support the recommendation of hydroseeding for large scale establishment of Fimbristylis cymosa.