Processing Tomato Yield and Fruit Quality Improved with Potassium Fertigation

Summary

The effect of K fertigation through subsurface irrigation lines on processing tomato (Lycopersicon esculentum Mill.) fruit yield and quality was evaluated in four field trials in California from 2002–04. Fields had exchangeable soil K between 0.48 to 0.85 cmol·kg –1, with high exchangeable Mg (10.6 to 13.7 cmol·kg –1) and a history of yellow shoulder (YS, a fruit color disorder) occurrence. K treatments evaluated included seasonal amount applied (0 to 800 kg·ha –1), fertigation method (continuous versus weekly), and timing (early, mid or late season); foliar K treatments were also included in the 2002 trial. In two fields total and marketable fruit yield were significantly increased by K fertigation, and fruit color improvements were observed in all trials. Among color parameters improved