Fig 7. Pollen viability as affected by phosphorus levels (0.1, 1, 10 and 26 mg l^-1 P in irrigation for P1–P4 respectively).

In 2012 (a) measured by Alexander reagent and in 2013 (b) by both Alexander reagent and fluorescein di-acetate (FDA) method (200–300 flowers per treatment). Different letters indicate significantly differences at p<0.05.