Description

Abstract: Arachis hypogaea germplasms TxAG4 (PI535816) and TxAG5 (PI535817), released for their resistance to Pythium myriotylum and Sclerotinia minor, are advanced generation F4-derived lines selected in 1979 from the cross Toalson (resistant to P. myriotylum) X UF73-4022. In Texas, the growth periods of TxAG4 and TxAG5 were equal to or 5 days longer than that of Starr; the main stems were usually taller and often more coarse. Most of the pods are 2-seeded but occasional pods have 3 seeds. TxAG4 has large or medium size pods with moderate constriction; TxAG5 has variable but mostly medium sized pods with moderate or no constriction. The shelling percentage of TxAG5 is equal to that of Starr, whilst that of TxAG4 is Generally 2-3% lower because of its shell density and thickness. The commercial acceptability of the lines is restricted because of their shelling percentage and the variability in pod shape and size. In 1987, 100-seed weight of TxAG4, TxAG5 and Starr averaged 49.5, 39.6 and 38.5g, respectively. Pod yields of both lines have equalled Starr and Tamnut 74. In field trials in south Texas over 4 years both Tamnut 74 and Florunner had a greater percentage of diseased pods than TxAG4 and TxAG5 in fields with a high incidence of P. myriotylum. In Sclerotinia-infested fields in Oklahoma during 1982 and 1985-88, the highest percentage of diseased TxAG4 and TxAG5 plants was 16% compared to 98% for Florunner.