EFFECTS OF MESQUITE (Prosopis juliflora DC.) LEAF EXTRACT AND SOIL FROM UNDERNEATH ITS CANOPY ON GROWTH, YIELD AND YIELD COMPONENTS OF ETHIOPIAN MUSTARD (Brassica carinata A.BRAUN)

Abstract

P. juliflora is known to interfere with the growth of plants growing in its vicinity by the release of allelochemicals during the decomposition of its litter. An attempt was made to determine the effects of different concentrations (0%, 5%, 10%, 15%, and 20%) of P. juliflora hexane and ethanol leaf extracts on seedling growth, yield and yield components of B. carinata. Soil seedbed and extracts were also prepared from soils sampled from different sites of distance gradient from P. juliflora to evaluate the same paramaters under laboratory conditions. Soil has also sampled from different sites in distance gradient from P. juliflora to grow B. carinata in pots in greenhouse. P. juliflora leaf extracts obtained by the two solvents significantly inhibited seed germination and seedling growth in a concentration dependent manner (0%, 5%, 10%, 15%, and 20%). Soil toxicity test conducted through soil-bed growth and soil extract treatment did not have any negative impact on measured parameter(germination percentage, radicle length, plumule length, shoot length and root length, whereas cultivation of B. carinata on soils obtained from different points in distance gradient from P. juliflora showed significant difference among sampling points(Beneath, edge, 1m and 2m). That is, germination, growth, yield parameters and yield found to increase when cultivated on soil samples away from P. juliflora invaded area. Generally, the results revealed that allelochemicals from P. juliflora are toxic to B. carinata that care must be taken when cultivating it around P. juliflora.