TITLE:
Additive Main Effect and Multiplicative Interaction Stability Analysis of Grain Yield Performance in Cowpea Genotypes across Locations
AUTHORS:
Kwabena Atakora, Harrison Kwame Dapaah, Kofi Agyarko, Margaret Esi Essilfie, Kwadwo Gyasi Santo
KEYWORDS:
Stability, Genotype, Interaction, Yield, Environment
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.4,
April
30,
2023
ABSTRACT: Crops are largely influenced
by climatic conditions during the growing season and therefore, minor deviation
from optimal conditions can seriously threaten yield. In view of this, knowledge
on the effect of environmental factors on crop growth and development could
reduce the possibilities of significant yield loss. There
have been statistical methods which have been
developed in respect to characterizing crops but the additive main effect and
multiplicative interaction (AMMI) method integrates analysis of variance and
principal components analysis into a unified approach. AMMI has been used in
the analysis of G × E interaction with greater precision in many crops.
The objective of this study was to assess the extent of genotype x environment
interaction and to select the stable cowpea
genotypes in Ghanaian environments over seasons using AMMI model. Eight genotypes of cowpea released by Crops Research
Institute of Ghana over two decades were selected for evaluation in two
locations and two seasons using RCBD with 3 replications in forest and
transitional zones of Ghana. When the mean yields of various genotypes were
subjected to the AMMI model, the results showed that, a highly significant (P 0.001) genotype by location and by year interaction
effects for cowpea grain yield was recorded with 63.1% of the total variation
attributable to environmental effects. The AMMI Bi-plot of PC1 and GGE Bi-plot
gave 80.8% and 89.3% respectively. Genotype Asontem (G3) had the highest yield
and was adapted to all the environments and seasons. Genotypes Asetenapa (G1)
and Soronko (G6) were however not stable with consistently low yield across all
the environments. It is recommended that farmers in Forest and transitional
zones of Ghana should cultivate the highly stable cowpea genotypes in order to
get stable yields across environments due to climatic change.