Cytological and morphological effects of atrazine and propazine application on grain sorghum

Effectiveness on weed control and injury on sorghum plants were compared for herbicides atrazine and propazine which were applied at four different rates, 0.56, 1.1, 2.2 and 4.5kg/ha. It was found that both herbicides at rates above 2.2kg/ha reduced plant height but propazine caused less injury than atrazine. The majority of cytological aberrations observed during meiosis were multiple nucleoli detected in diplotene and early diakinesis cells and asynchronization of chromosome movement as noted in metaphase II and telophase II cells. Cells with lagging chromosomes and aneuploid cells were rare and should not hinder the used of these herbicides.