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Growth and Partitioning Characteristics of Four Peanut Genotypes Differing in Resistance to Late Leafspot
Author(s) -
Pixley K. V.,
Boote K. J.,
Shokes F. M.,
Gorbet D. W.
Publication year - 1990
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1990.0011183x003000040007x
Subject(s) - point of delivery , biology , fungicide , arachis hypogaea , cultivar , horticulture , crop , leaf spot , resistance (ecology) , agronomy , growing season
Genetic resistance in peanut ( Arachis Hypogaea L.) to foliar diseases caused by Cercospora arachidicola Hori (CA) and Cercosporidium personatum (Berk. & Curt.) Deighton (CP) has usually been associated with low yields and late maturity. Some recently developed genotypes have partial resistance to CP and good yield potential. This study was conducted to understand growth and partitioning characteristics that contribute to yield potential of three leafspotresistant genotypes relative to the widely grown but susceptible cultivar Florunner. Crop growth, vegetative growth, reproductive growth, and partitioning intensity of Florunner, ‘Southern Runner’, F81206, and MA72x94‐12 were measured in field studies during two seasons in the presence or absence of fungicidal control of leafspots. In fungicide‐treated plots, the genotypes had similar crop growth rates, but differed in assimilate partitioning to pod growth (92, 80, 77, and 53% for Florunner, Southern Runner, F81206, and MA72x94‐12, respectively). In treated plots, high partitioning of assimilate to pods and early onset of pod fill enabled Florunner to achieve high yield in 127 d. In untreated plots, this high intensity of partitioning to pods limited Florunner's leaf production during pod fill and precluded replacement of diseased leaves. By contrast, Southern Runner, F81206, and MA72x94‐12 compensated partially for leafspot‐induced defoliation; later onset of pod fill (6 to 16 d) and lower partitioning to pods allowed greater leaf area growth during pod fill. A combination of leafspot resistance, lower partitioning to pods (allowing leaf growth), and slightly longer pod fill resulted in satisfactory yields from Southern Runner and F81206 without fungicidal control of leafspot.