Phenology, growth, and seed tuber yield in potato (Solanum tuberosum L) varieties as influenced by plant density at adet, northwestern Ethiopia

The effect of planting density on producing quality seed tubers using shoot tip cuttings and conventional methods from tubers has not been studied in Ethiopia. An experiment was conducted to determine the effects of spacing on seed tuber yield and related traits of potato cultivars at Adet Agricultural Research Center in northwestern Ethiopia during the 2023 cropping season. The treatments consisted of two potato varieties (Belete and Gera) propagated by shoot tip cuttings at four inter-row spacings (30, 40, 50, and 60 cm) and intra-row spacing (15, 20, 25, and 30 cm). The two varieties propagated using seed tubers at 60 cm inter-row and 30 cm intra-row spacing. The experiment was laid out in a randomized complete block design with three replications. The results showed that the main effects of variety, inter-row spacing, intra-row spacing, propagation method, and the interactions of variety, inter-row spacing, and intra-row spacing significantly influenced the parameters considered. The earlier tuber initiation (43 days) and 50 % flowering (51 days), were recorded from Gera variety propagated using shoot tip cutting. The earlier maturity date (85 days) was recorded from Belete variety propagated using shoot tip cutting. Gera variety propagated using shoot tip cutting at 40 cm inter-row spacing and 25 cm intra-row spacing recorded the longest plant height (85 cm). Belete variety propagated using shoot tip cutting at 30 cm × 15 cm inter- and intra-row spacing produced the highest leaf area index (5.51). The highest seed tuber number per hill (3.96), the highest average seed tuber weight (63 g), and the highest seed tuber weight per hill (248 g) were recorded from propagation by seed tuber (control). Gera variety propagated using shoot tip cutting at 50 cm × 15 cm recorded the highest seed tuber yield (21.11 tons ha−1), which is 57.3 % seed tuber yield increment over seed tuber propagation (control). Based on the study findings, it is recommended to propagate potatoes by shoot tip cutting at a spacing of 50 cm inter-row and 15 cm intra-row for seed tuber production in the study area.