Forecasting model based on morphological characteristics for yield of konjac (Amorphophallus muelleri Blume) planted in Tak province, Thailand

Abstract

Importance of the work: The useful part of konjac (Amorphophallus muelleri Blume) is its tuber; however, it is difficult to estimate its annual production without weighing the tubers. The newly developed forecasting model aims to provide valuable insights and support decision-making processes related to productivity management, marketing and crop planning.
Objectives: To study the relationship between konjac tuber weight and vegetative morphological factors.
Materials & Methods: Data were collected from 163 individual konjac plants growing in sample plots. The vegetative morphological factors measured were: stem diameter at ground level, stem height, length of the longest leaf, crown cover, number of bulbils, tuber diameter and tuber weight. A model was developed to forecast konjac productivity using stepwise multivariate regression.
Results: The study identified correlations between the vegetative morphological factors of A. muelleri, with the stem diameter at ground level (D₀) being the most reliable factor. The equation used to predict A. muelleri tuber weight (Y) was log Y = –3.34 + 2.17 log D₀, which had a high coefficient of determination (0.95, p < 0.01). However, this equation was specific to A. muelleri productivity in Tak province.
Main finding: The developed equation should be valuable for tuber weight estimation without the need for tuber extraction. It should assist stakeholders to meet market demand.