ALLOMETRIC ESTIMATION OF THE BIOMASS OF Musa spp. IN HOMEGARDENS OF TABASCO, MEXICO

Abstract

Estimates of biomass in homegardens are primarily based on the tree component and few studies quantify the perennial herbaceous component. This component is of importance in the humid tropics of Mesoamerica, where distinct varieties and species of banana (Musa spp) are cultivated. This crop represents a dynamically stable biomass within homegardens and provides owners with continual production for alimentation and cash income. The aim of this study was to produce an allometric model for estimating the biomass of banana plants using dasonomic data, compare it to other models and estimate the biomass of cultivated banana plants from homegardens in the state of Tabasco, Mexico. This was based on the hypothesis that 1) the formulation of specific allometric models results in more precise estimations of the standing biomass of banana plants; and 2) banana plants contribute a significant proportion of the total biomass in homegardens. Dasonomic data and the dry weight of the above and below ground components of 30 individual plants of the most abundant species of banana (Musa balbisiana Colla) were collected in homegardens of the Los Rios region in Tabasco, Mexico. The mean biomass of the total plants of M. balbisiana harvested from homegardens was 5.85 kg plant-1, with a range of 0.52 – 13.32 kg plant-1. The above-ground and corm biomass represent 87.6% and 12.4% of total biomass respectively. The above-ground biomass (AGB) was strongly correlated with pseudostem diameter (DBH) and to a lesser degree with height data. The Husch and Schumacher – Hall models, with the variables pseudostem diameter at a height of 30cm (d30), height of the pseudostem (HF) and total height (HT), performed best statistically; however, based on the crossed validation, the best model was that proposed by Kopezky, with the equation AGB= -0.0927+0.0203*DBH2. In homegardens with banana plants, the banana biomass was between 0.1 and 1 t ha-1, and in some cases between 2 and 5 t ha-1. The mean density of the total biomass of the banana plants, in a sample of 69 homegardens where bananas were present, was 688 kg ha-1, corresponding to 2% of above-ground biomass in the homegardens of the region of study.