RESPONSE OF SELECTED PEANUT GERMPLASM LINES TO LEAFSPOT AND SOUTHERN STEM ROT(1)

Forty peanut Arachis hypogaea L. entries received from ICRISAT plus fo ur U.S. cultivars were evaluated three years for resistance to early l eafspot Cercospora arachidicola Hori., late leafspot Cercosporidium pe rsonatum (Berk. and Curt.) Deighton, and southern stem rot Sclerotium rolfsii Sacc. Early leafspot ratings for RMP-12 were two standard devi ations below the mean of all entries all three years of the test. The disease scores for RMP-91 were low in two of the three years. None of the entries were consistently superior to the four U. S. cultivars in late season leafspot scores. Stem rot incidence for Tamnut 74 was lowe r than the mean of all entries in two test years, while PI 414331, RMP 91, Robut 33-1, and PI 393516 showed indications of above average sus ceptibility. Foliar diseases were severe on Tamnut 74. The pod yield o f Southern Runner in these irrigated tests was two standard deviations above the test mean in all three years of the test. However, the reac tion of Southern Runner to leafspots and stem rot was not consistent w hen compared with the test mean. The high pod yield combined with aver age or above resistance to late leafspot and southern blight adds attr activeness to the culture or use as a parent of this cultivar. The pod yield of RMP- 1 2 was above average in two of the three years and the southern blight incidence was equal to the test mean. Multiple diseas e and agronomic evaluations under natural field culture can be useful in the choice of genotypes for use as parents and cultivars for peanut improvements programs with focus on low input and sustainable agricul ture.