Composition and method of treating plant material

A biostimulant composition is provided, the composition comprising Aegle marmelos leaf particulate or an extract from Aegle marmelos leaf, the extract having been obtained with a solvent. The composition may also include a liquid carrier, a surfactant and/or a further biostimulant. The additional biostimulant may be orthosilicic acid, a weak acid or an amino acid. The weak acid may be phosphoric acid, citric acid, salicylic acid, tartaric acid, ascorbic acid, humic acid or fulvic acid. The amino acid may be tyrosine and/or phenylamine. A method of treating an area comprising one or more plants and/or plant propagation material, the method comprising applying to said area Aegle marmelos leaf particulate or an extract from Aegle marmelos leaf. Also claimed is a pre-composition comprising the particulate or extract of Aegle marmelos leaf. The pre-composition being suitable for mixing with a carrier liquid to form a biostimulant composition. Also claimed is a substrate for supporting the growth of plants comprising Aegle marmelos leaf particulate or an extract from Aegle marmelos leaf, the extract having been obtained with a solvent. A method of producing a biostimulant from one or more leaves is also claimed.