Effects of Tillage Systems on Southern Blight and Pod Yields of Five Runner Peanut Genotypes

Abstract

Four runner-type peanut (Arachis hypogaea L.) cultivars, moderately resistant to Pythium myriotylum pod rot and/or southern blight (Sclerotium rolftii), and Florunner were compared under full-tillage, minimum-tillage, and no-tillage cultural systems from 1985 to 1987. Disease, yield, and grade evaluation were made to ascertain if the soilborne disease resistance would be beneficial to peanut production under minimum-tillage systems. Averaged over genotypes, yield was 500 kg/ha more with full-than no-tillage. In one of three years, Florunner yielded less than the highest yielding cultivar. Neither pod rot nor southern blight was a major deterrent to minimum-tillage production. Genotype differences in number of southern blight infection sites, over tillage systems, occurred in twoyears but the relative disease incidence was inconsistent among cultivars over years. More pod discoloration occurred in Florunner than in all other cultivars in two of three years. Percent sound mature kernels (SMK) + percent sound-split kernels (SS) averaged 3.6% less for the no-tillage than for the full-tillage system, and in all years the grade for Florunnerwas as good or better than for all other cultivars. A Significant genotype x tillage system interaction was apparent for SMK + SS. TX835820 and TX835841 grades were Significantly lower with no-tillage systems while other cultivars produced no significant changes in grade.Key Words: Groundnut, Sclerotium rolfsii, southern blight, notillage, minimum-tillage.The use of minimum-tillage and no-tillage production practices has reduced production costs in com, grain sorghum, soybeans, and other crops (1,10,13,14,15,16,18,19,21). However, limited research (2,3,4,5,6,7,8,9,11) has been reported with the use ofno-tillage cultural practices in peanuts. Minimum-tillage or no-tillage production practices reduce soil erosion and water runoff. Unger and coworkers (19) noted that crop residue on the soil surface nearly eliminated erosion problems. Musick et al. (14) reported that a heavy mulch after irrigated wheat increased soil water storage 6 em in an Ll-month fallow. The extra soil water increased subsequent grain sorghum yield by 1120 kg! ha.Peanut pod yields with minimum-tillage and no-tillage have varied among locations. Wright and Porter (22) stated that no-tillage peanuts matured later than conventionally tilled peanuts and produced lower pod yields and grade than peanuts produced with full-tillage. Colvin and co-workers (4) stated that peanut yields were higher in several minimum-tillage systems with in-row subsoiler than those produced with full-tillage methods. They found that peanut grade was not influenced by a minimum-tillage system, while Hartzog and Adams (12) found that the elimination of deep tillage did not affect either yield or grade.In early work by Boswell and Grichar (2, 3), Florunnernotillage plots yielded 1000 to 1200 kglha less than full-tillage, They also reported southern blight was a major problem in the plots with surface residue. A later study by Grichar a...

Initial Growth of Peanut Cultivars at Presence of Different Sugarcane Straw Quantities

“…Even do not reaching crop productions in this experiment, data agree with Grichar and Smith (1991) that cites that production results can be subjected to conduct characteristic of peanut cultivars.…”

Sistemas conservacionistas de manejo do solo para amendoim cultivado em sucessão à cana crua

“…Embora a IAC-Caiapó apresente maior potencial produtivo, decorrente do maior número de estruturas reprodutivas produzidas, revela desenvolvimento inicial lento, provável razão para o baixo desempenho no cultivo mínimo em Ribeirão Preto. Em sistemas conservacionistas há atraso no desenvolvimento inicial e invariavelmente o momento da colheita deveria ser postergado, em relação ao sistema convencional, pois o arranquio antecipado pode reduzir a produtividade em 15% e o rendimento em 21% (Grichar & Smith, 1991;.…”

“…Média de quatro repetições (1) . (Grichar & Smith, 1991;Grichar, 1998;Jordan et al, 2001), as quais relatam perdas de 3% no rendimento de grãos nos sistemas conservacionistas.…”

“…Os resultados de produção podem (Grichar & Smith, 1991) ou não depender das características de porte das cultivares de amendoim Grichar & Smith 1992). Além disso, deve-se considerar que nos sistemas conservacionistas podem ocorrer diminuição da incidência de Cercospora arachidicola , redução de danos ocasionados por ataque do tripes e pela incidência de virose TSWV, manutenção da umidade do solo e redução do custo de produção (Scholar et al, 1995).…”

Influência do preparo do solo em área de reforma de canavial na qualidade física do solo e na cultura do amendoim

“…O rendimento de grãos foi maior no sistema onde a palhada foi queimada, em relação aos tratamentos onde a palhada permaneceu no sistema para ambas cultivares (Tabela 1 e 2). Estes resultados concordam com a maioria das pesquisas publicadas (GRICHAR & SMITH, 1991;WRIGHT & PORTER, 1991;GRICHAR, 1998;JORDAN et al, 2001) …”