“Fusarium oxysporum f.sp. radicis-lycopersici, the causal agent of Fusarium crown and root rot (FCRR), is a serious soilborne disease of tomato. Soil fumigation and host resistance may reduce the impact of this disease, but other alternative management strategies are needed because these options may not always be available or effective. The purpose of this study was to determine the potential of silicon (Si) to reduce the disease severity of FCRR. Seven-day-old seedlings of Bonny Best tomato, susceptible to FCRR, were transplanted
in sand culture amended with Hoagland’s nutrient solution with (+Si) or without (−Si) 100 mg Si/l. At 3 weeks after transplanting, three inoculum concentrations 0, 106 and
107 conidia/plant were used to inoculate the seedlings. Disease Roscovitine in vivo severity and silicon concentration were evaluated at 4 weeks after inoculation. Disease progress over time was investigated using the seedlings amended with Si or without Si and inoculated with 0 or 106 conidia/plant. Disease severity was evaluated at 2, 3, 4 and 6 weeks after inoculation. After rating disease, evaluated plants were divided into shoots and roots for silicon concentration analysis. Si significantly reduced the severity of FCRR on the stem of tomato at 4 weeks after MG-132 manufacturer inoculation. Results of disease progress suggested that the decrease in the disease severity of FCRR by Si amendment was probably due to a delay in onset in initial infection of roots and the movement of the pathogen from roots to stems. Si contents of roots and shoots SPTLC1 were significantly higher in tomato plants supplied with Si
than in those without Si. Moreover, the increase in the Si content of roots was significantly correlated with the reduction of disease severity of root, crown and stem, indicating a silicon-mediated resistance. Supplying Si to tomato seedlings can reduce the disease severity of FCRR, providing an alternative disease management strategy. “
“The anthracnose stalk rot of corn (ASR), caused by Colletotrichum graminicola, is a major disease of this crop and occurs in most Brazilian regions where corn is grown. Despite its widespread occurrence, there are no estimates of the effect of ASR on the yield of corn under the Brazilian conditions. In this study, we evaluated the effect of ASR on corn hybrids yield. Two experiments were conducted (first crop 2007/2008 and second crop, 2009) in areas with a history of occurrence of leaf anthracnose and ASR. Five hybrids were evaluated in the first and second crops: AG1051, BRS 1001, BRS 1010, BRS 1035, P30F80 and BRS 1010, 2B710, P30F80, DKB390, BRS 1035, respectively. At harvest, we evaluated the incidence of plants with anthracnose stalk rot (IPASR), and we selected pairs of healthy and diseased plants to quantify the effect of ASR in the ear weight (EW), grain weight (GW) and the weight of a sample containing 100 kernels (W100).