Yield and Market Quality of Seven Peanut Genotypes as Affected By Leafspot Disease and Harvest Date1

The effects of leafspot disease (causal organisms Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton) on the yield and market quality of peanut (Arachis hypogaea L.) must be understood to more accurately assess genetic potential of breeding lines. Seven peanut genotypes were grown without fungicide application at two locations, Gainesville and Marianna FL, for three years and harvested at three biweekly dates. Consistent pod yields near 5000 kg ha-1 were obtained for leafspot resistant breeding line 94 at Marianna when it was harvested later than 142 days after planting (DAP). Other resistant lines also reached maximum production at late harvests, even though disease incidence increased for all resistant lines. Highest yields of susceptible lines occurred ca. 120 DAP, with the susceptible cultivar Florunner producing over 3400 kg ha-1 at Marianna. Although disease pressure on the susceptible lines was heavy at 120 DAP, pod yields did not decline until later harvests, indicating that a major effect of the leafspot disease was the loss of pods already produced. Increased disease pressure was poorly correlation with seed size or total sound mature kernels in either resistant or susceptible lines.