Evaluation of Calcium Uptake of Peanut (Arachis hypogaea L.) Seeds at Various Developmental Stages.

Calcium is an indispensable nutrient for proper peanut pod development and indicative of seed quality.  Recent evidence suggests that it is taken up throughout development, which could allow for pre-harvest evaluation of seed quality.  A study was conducted to evaluate the effects of sampling time, maturity class, and Ca treatment on seed weight, Ca concentration, and total Ca in the seed.  A field study was conducted at Wiregrass Research and Extension Center, AL, in 2012 under non-irrigated conditions using two of the most popular cultivars grown in the Southeast, Georgia 06G and Georgia Greener.  Treatments included application of flue gas desulfurized (FGD) 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.  Results showed that mature seeds (brown and black) had higher Ca concentration and total Ca than early-stage seeds (yellow1, yellow2).  As peanut size increased, more Ca was absorbed, thus increasing the total Ca, but maintaining a relatively consistent seed Ca concentration.  Application of gypsum and lime at 1120 kg ha^-1 increased seed Ca and total Ca compared to the control and the 560 kg ha^-1 gypsum treatment. Since seed Ca concentration was relatively consistent during the last month prior to harvest, seed Ca concentration could be used to evaluate seed quality prior to harvest allowing for possible management to improve Ca prior to harvest.