(46) Response of Container-grown Cotoneaster dammeri to Rates of Dibbled and Pre-incorporated Controlled-release Fertilizer in Three Different Media
Plug-rooted liners of cotoneaster (Cotoneaster dammeri C.K. Schneid. `Coral Beauty') were grown in 6-L nursery containers filled with three different media: 73 pine bark: 22 peat: 5 pea gravel (Medium 1); 60 pine bark: 25 peat: 15 compost (Medium 2); and 50 pine bark: 50 compost (Medium 3). Plants were fertilized with Polyon (Nutryon) 17–5–12 (17N–2P–5K) 6-month controlled-release fertilizer at various rates (0, 2.5, 4.5, 6.5, and 8.5 kg·m-3 incorporated or dibbled (placed under the liner at potting). Shoot dry weight of cotoneaster increased with increasing fertilizer rates in all three media, and was consistently higher with dibble (calculated maximum ranges, 269-362 g/plant at 6.1–7.5 kg·m-3) than with pre-incorporated (127-263 g/plant at 6.4-8.5 kg·m-3) fertilizer. Trends for root dry weight were similar with dibbled fertilizer but nonsignificant with incorporation, while those for shoot: root ratio were reversed to those for shoot dry weight. Positive correlations were observed between foliar contents of N, P, and K and shoot dry weight from both dibbled and incorporated treatments, as well as root dry weight from dibbled treatments. With incorporation, however, only foliar K was correlated with root dry weight.