Figure 1 represents leaves chlorophyll and active iron of Le Conte pear as affected by different iron concentrations used in this work.
In general, both leaf chlorophyll content and active iron gradually increases by increasing the concentration (Conc.) of iron. The highest significant were achieved by high Conc. (1000 and 2000 ppm) with no differ between them, except the 2nd season in active iron. Meanwhile, the lowest significant recorded by the check treatment (foliar with water) as compare with other treatments in both studied seasons. Our results are in agreed with many studies were tested iron (II) sulfate as a foliar fertilizer in several fruit crops led to increases in leaf chlorophyll …show more content…
The highest statistical P content revealed with low level of Fe at 250 ppm (0.22 & 0.24 %), then Fe at 500 ppm (0.16 & 0.17 %). While, the significant reduction came by the high Fe level 2000 ppm (0.10 & 0.11%) respectively in both seasons, our results were agreement with (Malvi, 2011) mentioned that there were antagonism between iron and phosphorus especially in the high levels.
Leaf K content: Leaves potassium concentration gradually increased by increasing iron levels. Fe at 2000 ppm recorded the highest significant increment of K content (2.41 & 2.56 %), Fe at 1000 ppm came next (2.14 & 2.27 % respectively). The lowest statistical was found by the control treatment (1.82 & 1.93 %) consecutively in the 1st and the 2nd seasons, the previous results are in line with (Malvi, 2011) mentioned that were a harmony between two mineral nutrients (Fe and …show more content…
The best treatment induced the highest statistical increase of Ca content by ferrous sulphate dose at 500 ppm (1.63 & 1.73 %). Followed by 1000 ppm (1.60 & 1.70 %), respectively. But the control treatment gave the lowest decrease of leaf Ca content (1.36 & 1.46 %) and the high level of iron 2000ppm (1.42 & 1.50%) consecutively, in the two seasons.
The results in case of calcium agree with (Malvi, 2011), proved that there is relationship between high iron levels and leaf calcium content. The reduction of leaf Ca content it may be due to the presence of antagonism between high iron level and calcium.
Leaf Mg content: From data in Table 1, Leaf content of magnesium was response slightly or no affected by all treatments. Ferrous sulphate sprayed at levels 500, 1000 and 2000 ppm were had a positive effect on leaf Mg content as compared with 250 ppm and unsprayed trees in both seasons. This results are in harmony by Twyman (1959) found that Increasing the total iron supply increases decreasing concentrations phosphorus, calcium and magnesium in leaves.