Fig. 4
From: Flowering in Persian walnut: patterns of gene expression during flower development
A general pattern of flowering genes expression and the date of different stages of flower development in walnut; flower induction (a, b) and initiation (c) occurred in the summer of last year. Flower differentiation (d, e) and anthesis (f, g) were observed in late March to early May of the same year. Harvest date (i) was from mid to late September. The graph C shows chilling and heat requirement of walnut trees cv. Chandler. An adequate winter chill and subsequent heat accumulation increase expression of flowering gene and release dormancy