Identifier

etd-11102015-114715

Degree

Master of Science (MS)

Department

Plant, Enviromental and Soil Sciences

Document Type

Thesis

Abstract

Studies evaluated impact of dicamba, 2,4-D, and glyphosate at reduced rates to sweetpotato at root formation (RF) and development (RD) growth stages. For DGA salt of dicamba at RF, glyphosate plus dicamba at 1/10x reduced storage root number 42%, canner grade yield 33%, and total yield 36%. With choline salt of 2,4-D at RF, storage root number compared to the non-treated (6.5) was reduced with glyphosate alone at 1/100x (5.1), 2,4-D alone at 1/250x (5.1), and glyphosate plus 2,4-D applied at 1/10 (4.2) and 1/1000x (5). Canner yield was reduced 32% with glyphosate alone 1/10x, 26 and 27% with 2,4-D alone at 1/10 and 1/500x, and 40% with glyphosate plus 2,4-D at 1/10x. Total yield was reduced 40% with glyphosate plus 2,4-D at 1/10x. For BAPMA salt of dicamba at RF, storage root number was reduced 34 and 23% with dicamba alone at 1/10 and 1/100x and 23% with glyphosate plus dicamba at 1/10x. Total yield was reduced with glyphosate alone at 1/750x, dicamba alone at 1/500x, and glyphosate plus dicamba at 1/10 and 1/250x. With DGA salt of dicamba at RD, U.S. no. 1 yield was reduced 70 and 91% with dicamba alone and plus glyphosate at 1/10x. Total yield was reduced 46 and 64% with dicamba alone and glyphosate plus dicamba at 1/10x. For choline salt of 2,4-D at RD, U.S. no. 1 yield was reduced 67 and 54% with 2,4-D alone at 1/10 and 1/100x, and 87 and 62% with 2,4-D plus glyphosate at similar rates. Compared to the non-treated, canner yield was reduced only with glyphosate plus 2,4-D at 1/10x. Total yield was reduced 60 and 85% with 2,4-D alone and glyphosate plus 2,4-D at 1/10x. With BAPMA salt of dicamba at RD, U.S. no. 1 yield was reduced with glyphosate at 1/10x (31%), dicamba at 1/10 (68%) and 1/500x (37%), and the 1/10 (83%), 1/250 (34%), and 1/1000x (30%) rate of glyphosate plus dicamba. Compared to the non-treated, total yield was reduced with glyphosate alone at 1/100x, dicamba alone at 1/10 and 1/750x, and the combination herbicide at 1/10, 1/100, 1/250, and 1/500x.

Date

2015

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Miller, Donnie K.

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