For 3 years (1993 to 1995) Solanum tuberosum L. var. Spunta. was grown unde
r different plastic mulches ([PE] sheets): (.25 mu thick, transparent PE, (
T1), 25 mu-thick, white PE, (T2); 50 mu thick-coextruded black-and-white PE
(T3), and 25 mu-thick black PE, (T4). Controls were left uncovered (T-0).
Six sampls were taken of the plant material to determine B, Cl, Zn, Cu, Fe
ana Mn concentrations. The optimum foliar range was determined and establis
hed for those micronutrients.