Trichoderma harzianum application improves turmeric (Curcuma longa L.) growth, yield and rhizome quality

Abstract

Turmeric (Curcuma longa L.) is a high-value medicinal crop of growing economic and pharmaceutical relevance. However, optimizing its yield and quality remains a major challenge in tropical agricultural systems. This study evaluated the effects of Trichoderma harzianum on agronomic performance, yield, and rhizome quality of turmeric. A field trial was conducted in Iquitos, Peru, using a randomized complete block design with four treatments (0, 2, 4, and 6 g of T. harzianum conidia per plant). Applications were performed at transplanting (0 days) and at 60, 120, and 180 days after planting. Agronomic traits such as plant height, number of leaves and shoots, and fresh and dry rhizome yield and rhizome quality (protein and curcuminoid content) were assessed. Rhizome production varied significantly among treatments (P<0.01). Observed yields increased from 6.52 kg per plot in the control to 8.92 kg at 4 g for fresh yield, and from 0.87 to 1.18 kg per plot for dry yield. Tukey’s test confirmed that all inoculated treatments outperformed the control (P<0.05), with no differences among inoculated groups. Regression modeling predicted an optimal fresh yield of 9.14 kg per plot (10.83 t ha-1) at 5.27 g per plant and a maximum curcuminoid content of 7.13% at 2.30 g per 100 g of dry rhizome. Yields declined at higher doses. These findings support T. harzianum as a promising biostimulant to improve turmeric productivity under tropical field conditions, requiring validation in broader production environments.