Differential impact of remotely sensed dry dekads on maize yield in Zimbabwe

Abstract

Moisture requirements for crops vary with the crop phenological stage. In this study, we test whether and in what way the sequence of the dry dekads derived from Vegetation Condition Index (VCI) recorded during the growing season affect maize yield. VCI was calculated from eModis NDVI long-term time series data ranging from 2001 to 2016. The Kruskal–Wallis test was used to test whether there were statistical differences in yield among administrative units with different sequences. Pairwise comparisons indicated that sequences with higher number of dry dekads have significantly lower maize yield than those with few dry dekads. Furthermore, sequences with dry dekads in the beginning of the vegetative stage reduce yield more than those that have the dry dekads at the end. Based on these results, we conclude that the phenological stage at which the dry dekads occur has a significant effect on maize yield.

Keywords:

• Dry dekad
• vegetation condition index
• maize yield forecasting
• phenology
• Kruskal–Wallis test

Disclosure statement

No potential conflict of interest was reported by the authors.