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

Abstract

The study aimed at evaluating the influence of environment on sweetpotato stability and identifying superior genotype(s) with high yield stability in the farmers’ field conditions. Six sweetpotato genotypes were evaluated for two years in ‘meher’ season (July- December), 2014 and 2016; four of the six genotypes were assessed for three years in the ‘meher’ season, 2012, 2014, and 2016. Planting was done in three replications in RCBD in three unique agro-ecologies: Endayesus-dry highland, Fachagama-dry lowland, Rarhe-moist lowland. Genotypes genetic merits were predicted using BLUP. The AMMI and GGE were used to test the genotypes stability. The ANOVA for AMMI model showed high significant difference (P0.01) for genotypes, environments, seasons, and the interactions. Environment (41.67%) and the genotype main effect (35.71%) contributed largely to the cumulative variance for three years testing of four genotypes and two years testing of six genotypes, respectively. Berkume (42.44 t/ha), Tulla (33.92 t/ha) and Kulfo (33.67 t/ha) were superior for total storage root tuber yield (TTRY).Both the AMMI and GGE biplot predicted Tulla and Kulfo as ideal genotypes with dynamic stability; Berkume with static stability to Rarhe. The environment main effect had significant influence in determining how genotypes expressed their genetic potentials and stability as shown by the AMMI model and GGE biplot. The AMMI model partitioned the studied agro-ecologies of the Tigray region into two mega sweetpotato growing environments; the dry high/lowland in one environment and the moist lowland in another, completely different, but with high potentials for sweetpotato production.

Orange-fleshed sweet potato [Ipomoea batatas (L.) Lam] genotype by environment interaction for yield and yield components and SPVD resistance under arid and semi-arid climate of northern Ethiopia

“…Hence genotypes Ininda, Gloria, Amelia and Kulfo were the four superior genotypes for TTY production, and genotypes Erica and Melinda were inferior for TTY production in all the studied locations (Figure 3). This finding is in agreement with similar studies (Yan and Tinka, 2006;Adebola et al, 2013;Lamaro et al, 2020;Karuniawan et al, 2021), who found variations in genotypes' stability and adaptability over environment and time.…”

“…This could be because of the significant difference in the sum of rainfall received and other differences in the locations' growth factors during the study period (Table1). This finding agrees with previous studies on G × E interactions of sweet potato germplasms where the environment had negative correlations for root tuber yield traits analysis (Zebyder, 2016;Lamaro et al, 2020). The center of the AMMI biplot origin represents the grand mean phenotypic response to the environment for tuber yield production: the positioning of genotypes or locations relative to the biplot origin provides an understanding of the G × L interaction for the TTY trait.…”

“…Genotypes with well-established vines, high fresh vine yield weight, and total tuberous yield and harvest index signify the genotype's ability to partition nutrients and moisture well in all parts without compromising tuberous root yield. Genotypes with high HI are good producers of TTY (Oriba, 2017;Lamaro et al, 2020). In agreement with this, genotypes Ininda and Gloria, with high HI, TTY and FVWt, were suitable for production of tuberous roots and fresh vines useful for food and animal feed, respectively.…”

Evaluation of Yield and Nutraceutical Traits of Orange-Fleshed Sweet Potato Storage Roots in Two Agro-Climatic Zones of Northern Ethiopia

“…Most high-dry-matter-content sweet potato cultivars are white or cream-colored and do not provide the minimum daily requirement for vitamin A [ 26 , 27 ]. However, some orange-fleshed varieties have a high content of dry matter, as well as a content of beta-carotene high enough to meet a person’s required dietary allowance [ 13 , 14 , 21 , 28 ]. The majority of farmers tend to cultivate white-fleshed sweet potatoes, which a have high dry matter content, low water content, and low beta-carotene content compared with orange-fleshed sweet potato genotypes, which have higher water content and beta-carotene content but a lower dry matter content [ 29 ].…”