Effects of a Liquid Organic Biofertilizer from Rubber Seed Cakes on the Growth of Rubber Plants in the Nursery in Côte d’Ivoire

Abstract

Rubber has a major role in the Ivorian economy. However, the production of seedlings in nurseries is limited by the scarcity of fertile substrates, leading to a high dependence on chemical fertilizers, the excessive use of which compromises environmental sustainability. With this in mind, the purpose of this study was to evaluate the effect of liquid biofertilizers formulated from rubber seed cakes on the growth of seedlings in nurseries. The experiment, conducted at the CNRA station in Anguédédou, was carried out using a randomized complete block design comprising five treatments: an absolute control (T0), a urea control (T1) and three liquid biofertilizers (T2: 1 kg of rubber seed cakes/10 L of water; T3: 2 kg of rubber seed cakes/10 L of water; T4: 1 kg of rubber seed cakes/10 L of water + 15 g of urea). Applications were made monthly for four months. The parameters observed were the diameter, the height, the growth rate and the vegetative vigour index. The results revealed that the T3 and T4 treatments significantly favoured the development of the plants, with higher diameters and heights as well as increased vigour compared to the controls. These performances reflect the agronomic efficiency of biofertilizers from rubber seed cakes, which are capable of improving growth while adding value to a local by-product. This strategy is a sustainable and environmentally friendly alternative to chemical fertilisers. However, further research is needed to adjust the doses and study the long-term effects after grafting and on the fertility of the substrate.