Calcium Uptake of Peanut Seeds By Developmental Stages.

Calcium is an indispensable nutrient for proper peanut pod development and indicative of seed quality; therefore, it is important to know Ca uptake by developmental stages for optimum timing of Ca application.  This study was conducted to evaluate the effects of sampling time, maturity class, and Ca treatment on seed weight, seed Ca concentration, and total seed Ca in order to develop a pre-harvest seed quality assessment.  A field trial was conducted at Wiregrass Research and Extension Center in Headland, AL, in 2012 and 2014 using two of the popular cultivars grown in the Southeast, Georgia-06G and Georgia Greener.  Treatments included application of flue gas desulfurized gypsum at rates of 560 and 1120 kg ha^-1 at early bloom, lime at 1120 kg ha^-1 at planting, and an untreated control.  Peanut maturity classes were determined using the hull scrape method.  Results showed that Georgia-06G produced greater seed weight but lower seed Ca concentration than Georgia Greener.  No significant difference was noted between the two cultivars on total seed Ca.  Addition of gypsum or lime had minimal effect on seed weight.  However, application of gypsum at early bloom or lime at planting significantly improved seed Ca concentration and total seed Ca compared to the untreated control.  When peanut seeds mature from yellow to black stage, more Ca was absorbed as seed weight increased, thus total Ca in seed increased, but a relatively consistent seed Ca concentration was maintained at each sampling time.  Therefore, seed Ca concentration has the potential to be used for evaluation of seed quality in early season, allowing for possible management to improve total seed Ca prior to harvest.