Three studies provided additional knowledge of beneficial effects of sudangrass for yield and quality increases of the Russet Burbank potato. Thro of these studies showed significant 'increases of both U.S. #1 and smooth tubers >280 g following green manures of sudangrass. These sudangrass (HS-33) effects did not differ from a sorghum-sudan hybrid . When a sudangrass green manure was compared with a fallow treatment, results of the first study showed mean yield increases of 36% for U.S. #1 tubers >280 g and yields of a second study by 34% for U.S. #1 tubers. This same sudangrass treatment outperformed green manures of either Austrian winter pea, barley, or sweet corn by increased U.S. #1 yields that ranged from 27% to 61%. By several lines of evidence, these benefits were found to extend beyond the effect of Verticillium suppression. Soil N was significantly increased following green manures of sudangrass, and these increases were in turn negatively correlated with wilt incidence and positively correlated with yields of both U.S. #1 tubers and tubers >280 g. Additional benefits also included significant increases of tuber grade percentages for marketable tubers and of smooth tubers >280 g. Benefits from sudangrass green manures beyond the effects of Verticillium suppression became further evident following a greenhouse study that involved field soil and sudangrass that had been grown in the same field. This study corAccepted for publication 7 June 2004. ADDITIONAL KEY WORDS: Fusarium spp., green manures, Verticilhum dahliae roborated both field experiments by showing increased yields with green manures of sudangrass that approximated 5.5 t ha-1 dry wt. As with the field studies, these yield benefits also extended beyond the effects of Verticillium suppression and were closely associated with significant increases of Fusarium equiseti, F. oxysporum, and F. solani. Throughout all studies, sudangrass green manures significantly increased microbial activities with increased populations of Fusarium spp. and increased concentrations in soil of mineralizable N, organic P, K, Mn, along with the percent soil organic matter -all factors that could have contributed to significant increases of yield and quality.
RE SUMENSe obtuvo informaciOn adicional sobre los efectos beneficos del sorgo pars el increment° de rendimientos y calidad de papa Russet Burbank por medio de tres estudios. Dos de ellos mostraron un significativo increment° de U.S. #1 y tuberculos uniformes >280g despues de haber recibido sorgo como abono verde. Los efectos del sorgo (HS-33) no mostraron diferencias con el sorgo hibrido (Tridan-8). Cuando se comparO el abono verde de sorgo con un tratamiento de barbecho, los resultados del primer estudio mostraron un promedio de increment° del rendimiento de 36% para tuberculos U.S. #1 >280g y los del segundo estudio 34% para. tuberculos U.S. #1. El mismo tratamiento de sorgo, super° a los abonos verdes de alverjilla, cebada y maiz dulce con rendimientos de U.S. #1 que variaron entre 27 y 61%. Junto con est...