Effects of individual and combined metal foliar fertilisers on iron- and manganese-deficient Solanum lycopersicum plants

Abstract

Aims Using Fe- and Mn-deficient Solanum lycopersicum

plants, we investigated the effects of Fe and Mn foliar

fertilisers, either individually or combined, on plant bio mass, leaf chlorophyll and metal micronutrient levels in

leaves and roots.

Methods Plants were grown in hydroponics with differ ent combinations of 0 or 45 μM Fe and 0 or 4.6 μM Mn.

Foliar fertiliser formulations (9 mM FeSO4 and/or

3 mM MnSO4, supplemented with a surfactant) were

applied in three consecutive doses. Fertilisation was

applied to the first three leaf levels, while upper leaf

levels were left untreated.

Results Iron and Mn deficiency led to characteristic

symptoms. Foliar treatments increased concentrations

of Fe and Mn, biomass and chlorophyll in treated leaves,

although re-greening was incomplete. 11–12 % of the Fe increase was in roots (likely mediated

via phloem transport), but no Fe increase occurred in

untreated leaves. Regarding Mn, a 2 % increase oc curred in untreated leaves, but no increase occurred in

roots.

Conclusions Iron fertilisation was effective not only in

leaves treated with the fertiliser but also in roots, where as Mn fertilisation had major effects on treated leaves

and minor effects on untreated ones. The combined

application of Fe + Mn was not detrimental to Fe- or

Mn-deficient plants