Root-yield performance of pre-release sweet potato genotypes in Kenya

Abstract

Objective: The focus of this study was to evaluate the yield and stability of superior sweet potato cultivars for release in Kenya. This is the first attempt to document experimental results that have led to the first and so far only sweet potato variety release in Kenya. Methodology: Ten national performance trials laid out as randomized complete block designs were performed on 14 sweet potato (Ipomoea batatas (L.) Lam.) genotypes in two geographical locations of Kenya. The trials were conducted to select local and introduced genotypes that were high yielding, stable, and tasty. Four experiments involving all the 14 genotypes were carried out in Nairobi while six experiments involving nine of the genotypes were carried out at three sites in Western Kenya. The stability of root yield and palatability test ranking were determined using appropriate statistical tools. Results: Significant (P = 0.05) differences in root yield between genotypes were observed for both locations. Mean root yield was higher in Nairobi (16,760 kg ha -1 ) than in Western Kenya (15,150 kg ha -1 ). The proportion of marketable roots was higher in Nairobi than in Western Kenya. Dry matter content was also higher in Nairobi (29.63%) than in Western Kenya (26.58%). Genotype x environment (G×E) interactions were significant (P = 0.05) in both locations. Conclusion and applications: Recommendations on the suitable varieties for official release are given. KEMB 10 and Mugande were the best performers in both environments. These two varieties contribute to enhancing food security among small scale household farmers in rural Kenya. Since its release in 2000, SPK 004 has contributed to enhancing the availability of the beta carotene micronutrient.

Meta-Analyses of Sweetpotato (Ipomoea Batatas L. Lam) Stability Performance in Different Agroecologies of the Tigray Region, Ethiopia

“…The significant interactions effect may imply that genotype interact differently with seasons and environment which caused variations in the TTRY across environments over time. This is in agreement with similar studies (Adebola et al, 2013;Mcharo et al, 2013), who found variations in root yield stability of sweetpotato cultivars across environments. The model partitioned the interactions into three significant Interaction Principle Component Analysis axes (IPCA) in the order of their relevance that is IPCA1 explained 75.76%, IPCA2 18.86% and IPCA3 5.38% of the variance.…”

“…This may signify how change in seasons affected genotypes' TTRY performance and stability in multi-environments over time. This finding corresponded to similar studies done by Mcharo et al (2013). Vitae (16.40 t/ha) and Kabode (16.85 t/ha) persistently maintained low yield in all the environments in the three years (Table 1), however, their average yield recorded in this study is still within the Variety release check yield range (16.0 t/ha to 34 t/ha) reported (Kapinga et al, 2010;Mwanga et al, 2009).…”

Performance of informal market sweet potato cultivars in on-farm trials in South Africa

“…These traits formed mega-environments and, consequently, require fewer environment sites to make recommendations. The significant environment effects on root yield are consistent with previous studies (Tumwegamire et al 2016, Mcharo andNdolo 2013). As expected, cultivar Ndou performed well under farmer conditions over several sites; thus, it findings need to be further validated using multi-location and multi-season data to confirm repeatability and for future recommendation of the cultivars.…”

Multienvironment Performance of New Orange‐Fleshed Sweetpotato Cultivars in South Africa

“…To produce suitable genotypes for multiple environments, G´Es should be accounted for and assessed in plant breeding programs (El Soda et al, 2014). Previous studies indicated significant G´Es in yield and yield components and in quality traits of sweetpotato (Grüneberg et al, 2005;Caliskan et al, 2007;Osiru et al, 2009;Mcharo and Ndolo, 2013). Previous studies indicated significant G´Es in yield and yield components and in quality traits of sweetpotato (Grüneberg et al, 2005;Caliskan et al, 2007;Osiru et al, 2009;Mcharo and Ndolo, 2013).…”

“…Relative to other major staple crops, such as maize (Zea mays L.) and wheat (Triticum aestivum L.), little information is available on G´Es in sweetpotato (Grüneberg et al, 2005). Previous studies indicated significant G´Es in yield and yield components and in quality traits of sweetpotato (Grüneberg et al, 2005;Caliskan et al, 2007;Osiru et al, 2009;Mcharo and Ndolo, 2013).…”