Miria Roldi

Agro industrial waste and sewage sludge can control Pratylenchus brachyurus in maize

Abstract If agro industrial byproducts are not properly disposed of, they can cause environmental pollution. These materials are rich in nutrients and could be useful in agriculture, with a possible role in the nematodes control, especially Pratylenchus spp., one of the worlds most pernicious species. Therefore, the aim of this study was to evaluate the effect of waste produced in the northeast of Parana State in controlling Pratylenchus brachyurus. Maize plantlets were transplanted to pots containing infested soil. After 90 days, the shoot was discarded and each pot top-dressed with the following: sewage sludge, vinasse, filter cake, poultry litter, or manipueira (liquid extract of cassava root). Maize seedlings were again transplanted to the pots where they remained for 70 days. The plants were then collected for evaluation in terms of height, fresh shoot, dry weight, root fresh weight, and number of nematodes/g root and per 100 cm3 soil. All treatments were effective in controlling nematodes. Enhanced plant development was observed after treatment with poultry litter. We therefore conclude that agro industrial waste provides a fresh alternative for controlling P. brachyurus.

Control of Meloidogyne paranaensis in coffee plants mediated by silicon

Coffee plants are considerably affected by the presence of Meloidogyne spp. and management is based in the use of resistant rootstocks. Systemic induced resistance could constitute an option to manage Meloidogyne paranaensis in coffee-growing areas. Coffee seedlings cv. Mundo Novo were treated with silicate before the inoculation of M. paranaensis to evaluate the potential control of this pathogen. We found, 120 days after the inoculation of 2000 eggs, that the application of silicate was effective to reduce the nematode population, based on reproduction factor and number of nematodes per g roots. Based on the present results, we suggest that the application of silicon constitutes an important alternative for the management of M. paranaensis in infested coffee-growing areas. Further studies are necessary to clarify the biochemical and molecular relationships between M. paranaensis and coffee in the presence of silicon.