Correlation coefficients, path analysis and disease reaction between yield and yield components in Potato (Solanum tuberosum L.) genotypes in Bale, South Eastern Ethiopia

Getachew Workalemahu,Wassu Mohammed

doi:10.14719/pst.2016.3.3.201

Abstract

Study on the relationships between yield and its components will improve the efficiency of breeding programmes by determining appropriate selection criteria. An investigation was carried out on 24 potato genotypes to find out the association among yield, yield components and their direct and indirect effects on tuber yield of potato. The experiment was laid out in randomized complete block design with three replications at Sinana Agricultural Research Center. The association was analyzed by correlation coefficient, and further subjected to path analysis to estimate direct and indirect effects of each character on tuber yield. Positive and significant genotypic and phenotypic correlation were found between total tuber yield and marketable tuber yield (rg=0.99), leaf area index (rg=0.82), plant height(rg=0.56), stem number per plant(rg=0.56), average tuber weight (rg=0.74) and biomass yield (rg=0.69). Path analysis of tuber yield and its components shows that marketable tuber yield and average tuber weight had maximum positive direct genotypic and phenotypic effect on total tuber yield indicating their importance in selection for tuber yield improvement.

Highlights

Potato is a very important food and cash crop especially on the highland and mid altitude areas of Ethiopia (Gebremedhin et al, 2008)
Correlation Coefficient Genotypic correlation coefficient values ranged as low as rg= -0.09 between total tuber yield and unmarketable tuber number per hill and as high as rg=0.99 between total tuber yield and marketable tuber yield
Positive and significant genotypic correlations in the range between rg =0.43 and rg = 0.99 was observed between total tuber yield per hectare and marketable tuber yield, leaf area index, plant height, stem number per plant, average tuber weight, biomass yield and marketable tuber number per hill (Table 2)

Summary

Introduction

Potato is a very important food and cash crop especially on the highland and mid altitude areas of Ethiopia (Gebremedhin et al, 2008). Negative and significant genotypic correlations was recorded between total tuber yield and percent severity index (rg= -0.8) and area under disease progress curve (rg= -0.6).

Results

Conclusion