XVI International Botanical Congess

Knowledge of genotypic differences in relation to root systems can contribute to answer agronomical problems such as transitory droughts and mechanical soil impediments. The objective of the present work was to quantify modification of the corn-root system, affected by compactation and water deficiencies, under controlled conditions. The experiments were done in pots of natural soil with five commercial hybrids (DK669, treatments applied were three compactation levels and two different water supplies. Root evaluation was made through root-biomass (BR) and root-length (LR). Significative differences of BR and LR were observed between hybrids with differential response to compactaction and water supply. Average BR and LR values were inversely related to the compactation increment. The negative effect of the highest density treatment was increased with the lowest water supply.