SodininkyStĖ ir darŽininkyStĖ 28(2)

of P was determined in the apple-tree leaves collected from the garden near the cementfactory, where assimilation of N was the highest. The optimum content of P inthe leaves of the apple-trees is 0.15–0.16 % (Sadowski, 1990). Plants suffering fromP deficiency are small and have a bluish green colour in the early stages of growth(Trevizan et al., 2008). In addition, fruit trees show reduced growth of new shoots andflower initiation is impaired (Mengel, Kirkby, 2001). On the other hand, potassiumdeficiency does not immediately result in visible symptoms, but affected plants showincreased susceptibility to frost damage and fungal attack (Trevizan et al., 2008). Theoptimal content of Ca was observed in the apple-tree leaves near the cement factory(optimum interval 1,1–2,0 %) (Sadowski, 1990). The main component of the dustemitted from the cement factory is Ca. The higher amount of Ca in the leaves fromthe cement factory garden may be a reflection of lower inputs of acid air pollutionas well as of its good supply and accessibility (Hrdlicka, Kula, 2004). Deficiency ofthis element was determined in the leaves sampled in the control garden, though thelack of Ca to fruit-trees occurs very rarely (Intensive technologies…, 2005). Also,calcium plays a key role in plant growth and development and the deficiency can deformyoung leaves (Trevizan et al., 2008). The optimal content of Fe was determinedin the leaves of the apple-trees growing near the cement factory. Deficiency of thiselement was documented for the control garden. Iron chlorosis (Fe deficiency) is animportant nutritional disorder among the fruit trees. It results from impaired acquisitionand use of the metal by plants rather than from a low-level Fe in the soil. The mostcommon cause of Fe chlorosis is the bicarbonate ion, which occurs in high levels incalcareous soils (Pestana et al., 2004). High levels of P in the tissues of the plants areoften associated with Fe deficiency. The deficiency of Fe in apple-tree leaves fromBabtai garden may influence the neutral pH level in the soil (~ 7,3) and excess of P inplant tissues. Insignificant excess of Mg content was determined in the leaves of theapple-trees near the cement factory. Cement dust, containing magnesium oxides, mayinfluence the accumulation of Mg in the leaves from the trees growing near the cementfactory. Mg corresponded the optimal interval (0.22–0.35 %, (Sadowski, 1990)in the leaves sampled from control garden. The highest Mn mean concentration wasapparently observed in the leaves sampled from the control garden. The amount of Mnin the leaves of the apple-trees growing in the vicinity of cement factory was lowerby a factor 10 as compared to the leaves collected from the reference site. Underelevated industrial emissions Mn deficiency was registered in the leaves of the appletree (Mochecki et al., 1986; Sadowski, 1990). According to Adriano (1986) the deficiencyrange of Mn for the most plant species is < 20 mg kg -1 . Only in the leaves ofthe control garden the concentration of B corresponded optimal value for the growth,in the cement factory garden the leaves of the apple-trees were B deficient (Wojcik,2004). The B content in the soil was significantly lower near investigated factoryas compared to control garden, so it can be considered, that B deficiency in the soildetermined its lower content in the apple-tree leaves. Boron deficiency is particularlyprevalent in the light textured soils, where water-soluble B readily leaches down thesoil profile and becomes unavailable for plants (Walsh, Golden, 1953). Similar to B thesoil and foliar Cu content presented significant decrease and lower than the optimum34