Allelopathic activities of selected Mucuna pruriens on the germination and initial growth of lettuce

Abstract

<p>The study was conducted to test allelopathic effects of some <em>Mucuna pruriens </em>on the germination and growth of lettuce. The effects of root exudates and leaf leachates of eight mucuna genotypes; <em>Mucuna pruriens </em>var. <em>utilis</em> cv. <em>cinza</em>, <em>Mucuna pruriens </em>var. <em>utilis</em> cv. <em>preta</em>, <em>Mucuna pruriens </em>var. <em>utilis</em> cv. <em>hassjo</em>, <em>Mucuna pruriens </em>var. <em>utilis</em> cv. <em>fvb</em>, <em>Mucuna pruriens </em>82/507, <em>Mucuna pruriens </em>82/508, <em>Mucuna pruriens </em>82/116, and <em>Mucuna pruriens </em>GA/94/002 were tested on the germination, radicle, and hypocotyl elongations of lettuce (<em>Lactuca sativa</em> var. Great Lakes 366). The effects of leaf leachates and root exudates of mucuna were tested using sandwich and plant-box methods respectively with lettuce as the receptor plant. Roots exudates inhibition varied significantly among genotypes (94.3%-98.5%). Root exudates of <em>Mucuna pruriens </em>var. <em>utilis</em> cv. <em>fvb</em> had the maximum inhibition (98.5%). Lettuce radicle inhibition gradually decreased with distance from the mucuna plant in a plant-box and with high correlation (r=0.910-0.952; p&lt;0.05) between lettuce radicle inhibition and distance from mucuna roots. The effect of 50 mg oven-dried mucuna leaves had significant inhibition on lettuce radicle elongation (12.0%-15.8% of untreated control). Leaf leachates had less effect on the hypocotyl elongation of lettuce (50.5%-72.0% of untreated control) at the same application of oven-dried leaves (50 mg/10 ml agar).</p>