3.5.2. Berry number per bunch of season 2 may be reduced by up to 50% in relation with grapevine water and nitrogen status at flowering of season 1 The relationships between berry number per bunch of season 2 and LNC and predawn at flowering of season 1 were negative (Fig. 2E and F). Based on the observed range of berry number per bunch, one can estimate the potential reduction of this component induced by a decrease in LNC and predawn at flowering of season 1: it would be up to 50% for both cultivars.
3.5.3. Water or nitrogen: which is the more limiting factor?
In contrast to what was observed for bud fertility, the two cultivars behaved similarly for berry number. At flowering in season 1, grapevine water status at flowering in season 1 was the more limiting factor, accounting for 23% (Aranel) to 38% (Shiraz) of variance of berry number per bunch in season 2 (Fig. 3). The grapevine nitrogen status at flowering in season 1 appeared to have almost no impact on the berry number per bunch in season 2.