Journal of Environmental Biology

Influence of diesel contamination in soil on growth and dry matter partitioning of Lactuca sativa and Ipomoea batatas

Kayode Fatokun* and Godfrey Elijah Zharare

Department of Agriculture, University of Zululand, Kwa-Dlangezwa 3886, South Africa

*Corresponding Author E-mail: kayfatokun@yahoo.com

Publication Data

Paper received:

04 October 2014

Revised received:

08 January 2015

Re-revised received:

27 May 2015

Accepted:

15 June 2015

Abstract

Phytotoxic effect of diesel contaminated soil was investigated on growth and dry matter partitioning in Lactuca sativa and Ipomoea batatas in greenhouse pot experiment at two concentration range (0-30 ml and 0-6 ml diesel kg^-1 soil) for 14 weeks. The results indicated that whole plant biomass, stem length, root length, number of leaves and leaf chlorophyll in two plants were negatively correlated with increasing diesel concentrations. The critical concentration of diesel associated with 10 % decrease in plant growth was 0.33 ml for lettuce and 1.50 ml for sweet potato. Thus, growth of lettuce in diesel contaminated soil was more sensitive than sweet potato.? The pattern of dry matter partitioning between root and shoot in both plants were similar. In 0-6 ml diesel contamination range, allocation of dry matter to shoot system was favoured resulting in high shoot: root ratio of 4.54 and 12.91 for lettuce and sweet potato respectively. However, in 0-30 ml diesel contamination range, allocation of dry matter to root was favoured, which may have been an adaptive mechanism in which the root system was used for storage in addition to increasing the capacity for foraging for mineral nutrients and water. Although lettuce accumulated more metals in its tissue than sweet potato, the tissue mineral nutrients in both species did not vary to great extent. The critical diesel concentration for toxicity suggested that the cause of mortality and poor growth of sweet potato and lettuce grown in diesel contaminated soil was due to presence of hydrocarbons in diesel. ?   

 Key words

Critical concentration, Diesel contamination, Dry matter partitioning, Hydrocarbons, Ipomoea batatas, Lactuca sativa

Copyright ? 2015 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).