Calcium Fertilizers Fail to Affect Pod Calcium Concentration and Yield of Four Snap Bean Cultivars

To measure the effect of added Ca fertilizer on the Ca concentration of snap bean pods, four snap bean cultivars were grown during Summer 1996 and 1997 at Hancock, Wis. Fertilizer treatments consisted of 80 kg of Ca per hectare applied as Ca sulfate (CaSO4·2H2O) or Ca nitrate [Ca(NO3)2], and the control (no Ca applied. The experimental design was a randomized complete block with a factorial set of treatments (4 × 3). Calcium sulfate was applied at planting, whereas Ca nitrate was split applied four times at weekly intervals starting 1 week before flowering. Yield and Ca concentration in pods were determined. The statistical analysis showed no significant effect of Ca fertilizers on pod Ca concentration or yield. A strong cultivar effect was detected for both parameters measured. `Evergreen' (5.47 mg Ca per gram dry weight) had the highest pod Ca concentration and `Labrador' (4.10 mg Ca per gram dry weight) the lowest. No significant fertilizer × cultivar interactions were observed. Results for pod Ca concentration remained consistent, even when significant year effects were found for both parameters.