Lime requirements of Boston ferns: II. Foliar and medium analysis

Abstract

Abstract Growth response and nutrient levels in the foliage and growth medium were compared using Nephrolepsis exaltata (L.) Schott ‘Com‐pacta’ ferns grown in a peat‐perlite medium with 4 rates of dolo‐mitic limestone (0.0, 1.2, 2.4, and 6.0 kg/m3) and 2 rates of gypsum (0.0 and 1.2 kg/m3). Incorporation of dolomitic limestone and gypsum resulted in greater growth compared to treatments without dolomitic limestone and gypsum, but dolomitic limestone rates of 1.2, 2.4, or 6.0 kg/m3 resulted in no difference in fern dry weight. Addition of gypsum resulted in higher foliar S levels. Suppressed fern growth was associated with lower foliar Ca and S levels. When 6.0 kg/m3 of dolomitic limestone was added to the medium, foliar N was lower and nitrates in the medium were higher compared to ferns grown with no dolomitic limestone. Addition of gypsum and dolomitic limestone to the medium increased soluble salt levels.