Danielle Mattei

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.

Host status and phenotypic diversity of rice genotypes in relation to Pratylenchus brachyurus resistance

The aim of this study was to assess the susceptibility of rice genotypes to Pratylenchus brachyurus and investigate the inheritance of resistance in the crop. Two experiments were conducted under controlled conditions, using naturally infested soil. Twenty-six rice genotypes were assessed, with maize used to show the susceptibility pattern. The maize was cultivated for 90 days and the initial nematode population was determined. Then, rice genotypes were cultivated, and the final nematode population and the reproduction factor (RF) were estimated 90 days after germination. All genotypes were susceptible to P. brachyurus in the two experiments but only one showed statistical differences, indicating variation in susceptibility, and genotypes Linhagem L03-107 and Cateto Amarelo scored higher than the control genotype, with RF of 8.80 and 9.48, respectively. Inheritance of resistance was poorly influenced by genotype genetics. Cluster analysis allowed the identification of five different groups of genotypes but there was low genetic variability among the genotypes.