Response of ‘sterling’ muscadine grape to calcium, magnesium, and nitrogen fertilization

Abstract

The effects of varying nitrogen (N), calcium (Ca), and magnesium (Mg) fertilization levels on plant growth and leaf elemental content of ‘Sterling’ muscadine grapes (Vitis rotundifolia Michaux) were studied in a 2‐year sand culture experiment. Increased N levels reduced leaf potassium (K), Ca, and Mn and increased leaf N and phosphorus (P) concentrations plus plant growth. Calcium fertilization increased leaf Ca, decreased leaf Mg, but did not affect plant growth. Magnesium fertilization reduced leaf K and Ca and increased leaf Mg plus plant growth. Visual symptoms, assumed to be Mg deficiencies, were decreased by Mg fertilization and highly correlated to leaf Mg content. Plants which received the highest Ca fertilizer level had fewer deficiency symptoms when treated with the highest rate of N. Calcium fertilization tended to slow both Mg uptake and deficiency symptoms reductions caused by increases in levels of applied Mg. Growth of ‘Sterling’ muscadine plants was positively correlated to leaf N and Mg and negatively related to leaf K, Ca, manganese (Mn), zinc (Zn), and copper (Cu) concentrations.