Variation in mineral composition op mango leaves as contributed by leaf sampling factors

Abstract

The contribution of leaf age, sampling direction, position of leaves on the shoot and sampling height on the N, F, K, Ca, Mg, S, Zn, Cu, Mn and Fe contents of mango leaves was studied by fitting step‐wise regression equations using dummy variable technique. Of the four factors studied, three factors, sampling direction, height and position of leaves on the shoot did not contribute significantly towards the variation on any of the elements studied. Only leaf age contributed significantly for the elements P, K, Ca, S, Cu and Mn.

P content decreased with leaf age explaining the variation to the extent of 98% through a quadratic fit. K content decreased linearly with age explaining the variation of 81%. Ca, S and Cu contents increased linearly and the contribution explained by age was 88, 60 and 30% respectively. Mn content increased with age following a parabolic curve and the variation accounted by this factor was 90%. In general, it can be concluded that 6 to 7 months old leaves from middle of the nonfruiting shoots sampled from all directions and heights were the ideal for leaf sampling.

Key words:

• plant nutrition
• plant analysis
• tissue testing