Fig. 5. (a) Titratable acidity in ripe fruit of tomato cultivar Counter grown in
nutrient solutions containing either low (N1) or high (N2) nutrient concentration
(controls), or after transfer of plants to lower (N2/1) or higher (N1/2) nutrient
concentration. The inset shows the differences between N2/1 or N1/2 and their
corresponding controls as correlated with time. (b) Titratable acidity of ripe
tomato fruit (N1, N2) as dependent on daily total radiation (means of the 42 days
recorded prior to each harvest date).