Author(s):
Sweet potato (Ipomoea batatas (L.) Lam.) is drought resistant, hardy and can grow in marginal areas. It is highly contributing to improving food security. The optimal production altitude range is 1500-1800 means above sea level (m.a.s.l). The study was conducted for one season over two locations, at Werer Agricultural Research Center (WARC) experimental field and Fentalle Woreda on a farmer’s field, where the altitudes represent lowlands (less than 1500 m.a.s.l). The objective was to evaluate morphological traits and select highly performing sweet potato genotypes for the lowland areas. The field experiments were arranged in a randomized complete block design with three replications. Each variety was planted on a 2 m long and 2.4 m wide plot consisting of four rows, which accommodate six plants per row and a total of 24 plants per plot. The middle two rows were used for data collection. The statistical analysis of variance for mean leaf length, plant height, vine length, marketable storage root yield and stand count at harvest showed significant differences among genotypes (P=0.0056) and locations (P<0.0001). The Pearson’s correlation analysis also showed that marketable storage root yield was weakly and positively associated with root diameter (r=0.29**), while a negative correlation was observed in plant height (r=-0.22*). The highest marketable storage root yield was recorded for Dilla (18.14 t/ha) followed by Kulfo and Wagobolige, whereas the lowest yielder genotypes were Cacilia which is statistically at par with Sumaia, Ininda, Jane and Gloria. Measured total above ground biomass by far greater at WARC than Fentalle, where the yields were statistically similar. From this, it is concluded that the above ground biomass of sweet potatoes is inversely correlated with storage root yield parameters. This might be due to the existence of photo assimilate competition between the above ground biomass and tubers. However, it needs further study to identify photo assimilate translocation and sink source relationships of sweet potatoes.
