Variation in Response to Calcium Fertilization among Four Runner‐Type Peanut Cultivars

Abstract

Seed quality of peanut (Arachis hypogaea L.) is influenced by seed Ca concentration, which is known to be affected by seed size and soil Ca fertility during seed production. Little is known about soil Ca requirements for large‐seeded runner‐type cultivars or for late maturing peanut cultivars that display poor seed quality. This study was conducted to determine if excess Ca fertilization during seed production would improve the laboratory germination and/or seedling emergence of large‐seeded runner‐type peanut cultivars (‘C‐99R’ and ‘AP‐3’) and late‐maturing runner‐types (‘DP‐1’ and C‐99R). Trials were conducted near Marianna, FL, in 2005, 2006, and 2007 using four cultivars and four gypsum treatments (0, 784, 1568, and 2352 kg ha−1) to provide excess soil Ca. Pretreatment soil extractable (Mehlich‐1) Ca was 589 kg ha−1 in 2005, 811 kg ha−1 in 2006, and 848 kg ha−1 in 2007, all of which are above the recommended level. The cultivar average seed size (g/100 seeds) ranking was C‐99R > AP‐3 > DP‐1 > ‘Georgia Green’, whereas average seed Ca concentration (mg kg−1) ranked Georgia Green > AP‐3 = C‐99R > DP‐1. Cultivar seedling emergence ranking was Georgia Green = AP‐3 > C‐99R > DP‐1 and germination ranked Georgia Green = AP‐3 > C‐99R = DP‐1. These results suggest that the relatively poor emergence of DP‐1 may be, in part, related to its relatively low absorption of seed Ca during seed production. Emergence of C‐99R increased as Ca fertilization increased in 2005, but not in 2006 or 2007. These results suggest that seedling emergence of some large‐seeded cultivars, like C‐99R, may require greater gypsum fertilization if soil Ca levels are marginal during seed production.