Substrates composed by blends of soil and organic materials has been usually recommended for production of Jatropha curcas seedlings, and castor hull is an alternative to compose such substrate. This by-product produced in large amount in the peeling process has high content of macronutrients. In order to evaluate blends of four organic materials with soil and castor hull, a trial was run in a greenhouse at Embrapa Algodão between October and December 2006 in a completely randomized design with four replications and two plants per plot. Treatments were blends of soil and castor hull with one of the following materials: garbage compost, bovine manure, sewage sludge, and castor meal. Control was a blend of soil and castor hull. At 55 days after planting, data on plant height, number of leaves, leaf area, stem diameter, dry weight of shoot and root, and leaf content of N, P, K, Ca, Mg and S were measured. All substrates were appropriate for growing Jatropha seedlings, although the blend of the soil and castor hulls without an additional organic source resulted in the lowest plant growth. The best seedlings growth and plant nutrition were observed when the blend contained garbage compost, sewage sludge or castor meal. The leaf content of macro nutrients had limted influence from the content of the same nutrient measured in the organic material used for the substrate composition.
Jatropha curcas L.; substrates; propagation
