Index, equilibrium and nutritional variations of iron in prunus domestica L. during its annual cycle

Abstract

The dynamics of the macro and micronutrients P, K, Fe, Mn and Zn were studied during the vegetative cycle of Prunus domestica L. Generally, the leaf content of P, K and Zn decreased during the vegetative cycle while Fe and Mn increased.

The optimum values of nutrients were: P= 4.34 mg.g^‐1; K= 17.50 mg.g^‐1; Fe= 1390 μg.g^‐1; Kn= 526 μg.g^‐1; Zn= 62 μg.g^‐1. The optimum range of binary ratios were: P/K= 0.240; P/Fe= 3.20.10^‐3; P/Mn=8.27. 10^‐3; P/Zn= 7.40.10^‐2; K/Fe= 1.38.10^‐2; K/Mn= 3.36.10^‐2; K/Zn=0.361; Fe/Mn= 2.577; Fe/Zn= 26.74; Mn/Zn= 10.47.

Physiological equilibrium was similar among plots. This was not influenced by sampling time and therefore it can be considered a constant. Fe, Mn and Zn equilibrium were scarcely different among plots and were unaffected by sampling time. The optimum value of the elements were: Fe‐Mn‐Zn= 70–27–3.

Iron index was related to plant metabolism. Iron index declined strongly during the same period and showed that iron was deficient during the initial stage of plant growth. The value of Iron index was: 0.25 and 0.22.

The best time for sampling of be appears to be in summer, during the period of vegetative growth.

Key words:

• Binary ratios
• Equilibrium
• Iron Index
• Diagnostic practices
• Crop