Abstract

K. L. Njoku, M. O. Akinola and B. G. Taiwo

The effects of gasoline fuel/diesel mixture on the germination of seeds of Vigna unguiculata, the survival of the seedlings and the growth of the plant were evaluated in this study. It involved adding 10, 20, 30, 40 and 50 ml of mixture of equal proportions of the two petroleum products to 5000 g of soil and sowing seeds of the V. unguiculata in the soils after which the survival and the growth of the plants were evaluated. Although the percentage germination of the seeds of the plant decreased as the quantity of the mixture added to the soil increased only the 40 and 50 ml treatments led to significant reduction of the percentage germination of the seeds (p < 0.05). The seedling survival decreased as the volume of the mixture added to the soil increased with no seedling surviving in the soil treated with 50 ml mixture of diesel and gasoline fuels 38 days after the germination of the seeds. The shoot length of the plant was adversely affected by the mixture of the petroleum products especially at week 9 of growth (p < 0.001). The dry weight of the plants grown in the soils treated with gasoline/diesel fuel mixture increased as the quantity of the mixture added to the soil increased with the 40 and 50 ml treatments having significant effects on the dry matter content and the root length of the plants (p < 0.001). All the treatments significantly inhibited the leaf area development of the plant at week 9 (p < 0.001). Significant differences (p < 0.05, 0.01 and 0.001) were observed among the plants in the different treatments for the different parameters measured. The results obtained in this study showed that spillage of mixture of gasoline and diesel poses threats to the survival and development of plants.