Chemical composition of leaf tissues of Sultana vines grown in nutrient solutions deficient in macro-elements

Abstract

Sultana vines, grown for one month after budburst in complete nutrient solution, were then grown in solutions deficient in N, P, K, Ca, Mg, or S for periods ranging from one to two months.
Shoot and root weights were obtained from vines at five sampling times. The first time was associated with nitrogen deficiency symptoms in the nitrogen deficient treatment and the second time with potassium, calcium, magnesium, and sulphur deficiency symptoms in the respective deficient treatments. In the phosphorus deficient treatment foliar symptoms were not observed but shoot growth was reduced. Shoot lengths were measured weekly.
Contents of P, K, Ca, and Mg in basal and recently matured laminae and petioles, and of N in laminae are discussed in relation to the choice of sampling tissue for diagnostic purposes.
It is concluded that the most satisfactory single tissue for diagnosing deficiencies of P, K, Ca, or Mg is basal petioles.
Concentrations (per cent dry matter) in basal petioles of 0.1 % P, 0.8% K, 0.5% Ca, and 0.2% Mg were associated with either the onset of deficiency symptoms or of reduced shoot growth.