Variations in growth performance of Amaranthus cruentus and Celosia argentea in response to leaf allelopathy of Anacardium occidentale

Abstract

The study was conducted to evaluate the allelopathic influence of leaf powder of Anacardium occidentale under various treatments of 20 g, 40 g, 60 g and 80 g on the growth performance of Amaranthus cruentus and Celosia argentea. Data generated from the measurement of growth parameters were subjected to Analysis of Variance and DMRT after the eighth week of growth. Results showed variations in the height, stem girth, number of leaves, leaf area and chlorophyll contents were observed in the test crops. Significant reduction (P<0.05) in stem height were recorded as from 20 g till 60 g treatments in A. cruentus but no significant difference was observed between 60 g and 80 g at 2 WAT. The variations in stem girth at 2 WAT was similar to that 4 WAT in C. argentea and A. cruentus at 4 WAT. At 6 WAT, significant reduction in the number of leaves started in 40 g treatment in C. argentea while in A. cruentus significant reduction started in the 20 after the eighth week of growth after the eighth week of growth g treatment and progressively reduced in all the treatments at P<0.05. Chlorophyll A of C. argentea leaves increases significantly (P<0.05) as the mass of leaf powder increased while chlorophyll A content in A. cruentus leaves reduced progressively at P<0.05 in all the treatments. The findings of this study revealed that the inhibitory effects of A. occidentale on the growth performance of the two vegetables were concentration-dependent and the pronounced inhibitory effects observed weeks after transplanting was adduced to the complete release of allelochemicals from the leaves after their total decomposition.