Fertigation with potassium increases size and yield in fresh figs growing in California
Nutritional status and evolution throughout the growing season has been studied in fig (Ficus carica L.) cultivars intended for drying; however, the literature is scarce regarding the effect of macronutrient concentrations on fresh figs. Research indicates that the levels of nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca) are important in generating high yields of marketable fruit. We quantified the effects of an intense fertigation program of potassium and calcium on two cultivars of fresh figs, 'Black Mission' and 'Sierra', on yield, marketable yield, fruit size, soluble solids concentration (SSC), titratable acidity (TA), and the reduction of culls. We also monitored leaf macronutrient concentrations throughout the growing season. As leaf macronutrients reached a plateau after June, leaf sampling collected in midsummer (July-September) is recommended for fresh fig. In general, nutrient evolution was similar in both cultivars with leaf N, P and K levels decreasing during late spring (May) to fall (October). These low N and K leaf levels in control trees late in the season suggest the potential benefits of applying N and K during the season. The fertigation program significantly increased yield and marketable yield in both cultivars, and increased fruit size in 'Sierra'. In 'Sierra' figs, leaf K concentration was positively correlated with yield, marketable yield, and fruit size. Fertigation had no effect on fruit SSC or TA for either cultivar.
Holstein, H., Crisosto, G.M. and Crisosto, C.H. (2017). Fertigation with potassium increases size and yield in fresh figs growing in California. Acta Hortic. 1173, 177-182
culls, fruit weight, quality attributes, ostiole-end splitting, side cracking, leaf sampling, macronutrients