Peanut Response to Prohexadione Calcium as Affected by Cultivar and Digging Date

Abstract

Abstract An experiment at two locations in 1995 and two locations in 1996 evaluated virginia-type peanut (Arachis hypogaea L.) response to the growth regulator prohexadione calcium (calcium salt of 3,5-dioxo-4-propionylcyclohexanecarboxylic acid) as affected by cultivars and digging dates. Prohexadione calcium at 140 g ai/ha was applied at row closure and again 3 wk later in 1995 or 140 g/ha at row closure and 70 g/ha 3 and 6 wk later in 1996. The cultivars AgraTech (AT) VC-1, NC 9, NC 10C, NC 12C, NC-V11, and VA-C92R were dug on three separate dates approximately 11d apart. Response to prohexadione calcium was independent of digging dates. Prohexadione calcium altered canopy architecture and increased row visibility at harvest for all cultivars although the response was greatest with NC-V 11 and least with NC 9. Prohexadione calcium hastened pod maturity, increased percentages of extra large kernels, total sound mature kernels, and fancy pods, and increased peanut value/kg irrespective of cultivars and digging dates. Yield response to prohexadione calcium was cultivar dependent. NC 9 was most responsive, with yield increased 7 to 16% at all locations. Yields of ATVC-1, NC 10C, NC 12C, and NC-V 11 were increased 9 to 15% at two locations and unaffected at two locations. VA-C 92R was the least responsive, with yield increased 5% at two locations and decreased 8% at two locations.