Temporal dynamics of soil nematode community in sugarcane field under low soil moisture

Plant-parasitic nematodes can cause severe losses in sugarcane fields in Northeastern Brazil. Additionally, the irregular rainfall distribution and prolonged drought during the 2012/2013 and 2013/2014 harvest severely reduced the crop production in the region. The purpose of this study was to evaluate soil nematode community dynamics in cane cultivation (variety RB867515) and the relations with the low soil moisture. The research was carried out after three consecutive drought years in a region with irregular rainfall with no irrigation. Soil samples were collected through May 2013 and August 2014, before sugarcane planting, at 3, 6, and 9 months after planting, and at harvest for nematode community and soil moisture analysis. Climatic variables including maximum and minimum temperature, relative humidity, and average rainfall, were used to characterize the area. Data were subjected to analysis of variance and principal component analysis. Results indicated that relationships exist between nematode community and stages in crop development, and soil moisture. Pratylenchus, Acrobeles, Criconematidae, Helicotylenchus, and Trichodorus were affected by soil moisture before planting, Acrobeles, Aphelenchus, Pratylenchus, Tylenchorhynchus, and Rhabditida were affected at 6 months after planting, Nothotylenchus at 9 months after planting, and Laimydorus, Helicotylenchus, and Trichodorus at harvest. Rhabditida population density was highest at 3 months after planting during the tillering stage.