Fig. 4

Light micrographs showing transverse views of cambium from high frequency and low frequency watering treatments. On 5 April 2015, after 10 days of application of high frequency watering, cell division in the cambium was initiated and many cambial cells started to divide (arrowheads) and differentiate into xylem cells (arrows, a). On the same date, with the application of low frequency watering, the cambium was in inactive condition (b). On 15 April 2015 after 20 days of application of high frequency watering, cambial cell division (arrowheads) and xylem differentiation (arrows) were observed on the cambial zone (c). On the same date, with the application of low frequency watering, cell division was absent in the cambial zone (d). On 25 April 2015, after 30 days of treatment with high frequency watering, cambial cell division and xylem differentiation were continued (e). On the same date, after treatment with low frequency watering, there was no new cell division in the cambial zone (f). C cambium, F fibers, Ph phloem, * vessel elements, Xy xylem. Bars = 50 µm