Effects of hydrology and applied gibberellic acid and paclobutrazol on the growth of the invasive exotic Lygodium microphyllum (Old World climbing fern)

I conducted a greenhouse study in order to examine the effects of hydrology and its interaction with gibberellic acid (GA3) on the invasive exotic Lygodium microphyllum (Old World climbing fern) growth and physiology. Three hydrological (flood, drought and field capacity) and three hormonal (gibberellic acid, paclobutrazol and water) treatments were studied using a 3x3 factorial experimental design. Plants under flooded conditions had a significantly lower relative growth rate compared to plants under field capacity or drought. Plants under flooded conditions showed a significantly lower specific leaf area and area-based photosynthetic rate than plants under field capacity and drought treatments, resulting in significantly lower mass-based photosynthesis. Overall, the variation in growth response to treatments was most explained by mass-based photosynthesis (r2=0.66). Treatments with gibberellic acid or paclobutrazol (GA inhibitor) resulted in no differences in growth as compared to untreated plants.