Muscadine (Vitis rotundifolia Michx.) vineyards can be difficult to establish due to poor vine growth or survival during the first year after planting. Effects of the planting hole (five types), root manipulation (three levels), and peat amendment (0% and 50%) on first-year growth were studied at two sites with different soil types: a sandy loam (well-drained) and a silty loam (moderately well-drained). The planting hole had the major effect at both sites; large holes (25 liters) shoveled with straight or angled sides resulted in more shoot and root dry weight and greater total root length than auger holes (21 liters) or small shovel holes (10 liters). Vine response to planting in a subsoil slot 0.5 m deep × 6 m long was similar to that in large holes in sandy soil and small holes in heavier soil. Root manipulation treatments had little effect on vine establishment. Root pruning at planting, with or without root separation, did not increase vine dry weight relative to an undisturbed root ball in either soil type, but total root length was increased by root pruning in the heavier silty loam soil. Peat amendment increased total root length in the sandy soil but not in the silty loam soil.
William C. Olien, C.P. Hegwood Jr, and James M. Spiers
Drew Bates, C.P. Hegwood Jr., and F.B. Matta
A field experiment was established in 1980 to determine the effect of different combined levels of ammonium nitrat e (196-695 kg/ha), potassium chloride (56-196 kg/ha) and magnesium oxide (123-437 kg/ha) on `Noble' and `Magnolia' muscadine cultivars (Vitis rotundifolia Mich.). NH4NO3 rates of 196 to 695 kg/ha did not produce significant differences in yields and pruning weights (P=0.05). 'Noble' produced similar yields at the highest and lowest N rates, with equivalent rates of K and Mg. KCl at 84 kg/ha and MgO at 123 kg/ha appeared to be adequate. Foliar levels of K, Mg and Zn were significantly different between treatments, but P, Ca and Fe were not (P=0.05). High levels of foliar K and Mg were associated with high treatment levels of K and Mg.