Calcium uptake and concentration in bell pepper plants as influenced by nitrogen form and stages of development

Abstract

Abstract Calcium uptake by bell pepper (Capsicum annuum L. cv. ‘California Wonder') varied by stage of plant development and N form supplied (NO3 ‐NH4 + ratios: 1:0, 3:1, 1:1, 1:3, and 0:1) in a hydroponic study. Uptake of Ca++ was highest at bloom and during fruit expansion, making the fruit development stage the highest demand period. Calcium uptake declined with each increasing increment of NH4 + relative to NO3 ‐ supplied, although fruit yield was not significantly reduced until the ratio of NH4 + to NO3 ‐ exceeded 50%. Tissue Ca++ levels in the blossom‐end of the fruit were reduced whenever NH4 + was included with N supplied. Vegetative yield of plants followed the same trend as that observed for total fruit dry weights. Our results indicate that pepper yields are higher when NO3 ‐ is the predominant form of N. Also, these results strongly suggest that Ca++ fertilizer applications should precede the bloom period and continue during fruit development to ensure adequate Ca++ availability for fruit deve...