Effects of household detergents on tomato growth.

Abstract

Laundry detergent containing anionic surfactants was used to test the effects it has on plant growth through irrigation water. Tomato plants were cultivated in bucket experiments and irrigated with clean tap water as the control experiment and tap water containing five different detergent concentrations. The detergent concentrations included 1.0grams, 1.5grams, 2.0grams, 2.5grams and 3.0grams which was the highest concentration. Each of these detergent concentrations was dissolved separately in 2000ml of tap water. The experiment was conducted for two months from the month of February to April in a screen house at Makerere University, Uganda. Statistical analysis was carried out by comparing the means of the shoot length, length of longest leaf and diameter of the stem using ANOVA. Multiple comparisons were made using a Tukey’s multiple comparison test. All the differences were considered significant at the 0.05 level. Means of the average number of leaves were compared using the non-parametric test, Kruskal-Wallis. Statistical analysis indicated that there was no significant difference between the means of the various treatments. Plants irrigated with low concentration of 0.75g/L, 1.0g/L and 1.25g/L had the best results in terms of growth performance. Moderate productivity of plants irrigated with tap water and water containing the lowest concentration of detergent. Plant growth reduced at high concentration of detergents in irrigation water because of high concentration of salts and surfactants. Compared to the control, the use of grey water in irrigation of plants could be a minor source of nutrients but can as well negatively affect the health, growth and development of plants if the detergent concentration is very high.