Response of maize varieties to induced stress of soil acidity

Abstract Soil acidity is a major problem for maize production in Western Ethiopia, where the soil pH ranges from 4.3 to 5.4, lower than the optimum pH range of 5.5 to 6.7 for maize growth. This problem leads to reduction in maize yield and exacerbates food insecurity in the region. This study aimed to identify maize varieties tolerant to acidic soils. Ten improved maize varieties (BH661, BH549, BHQP548, BH547, BH546, BHQPY545, BH5212, BH5211, Gibe2, and Gibe Awash) were evaluated under five pH levels (3.5, 4.5, 4.8, 5.5, and 6.5) in a pot experiment at Bako National Maize Research Center in 2023, using a randomized complete block design in a factorial arrangement with three replications. The results showed that both soil pH and maize variety significantly affected growth variables. Maize variety BH547 showed the best performance in most growth variables, including root number (12.87/plant), root fresh weight (9.73 g/pot), shoot dry weight (4.33 g/pot), total dry weight (8.23 g/pot), root length (62.53 cm), and root dry weight (6 g/pot), while BHQPY545 consistently underperformed in all measured variables. However, stress‐induced measurements showed a different trend. BH5212 exhibited the maximum relative root elongation (67.49%), followed by Gibe Awash (61.74%). For relative root dry matter production, BHQP548 showed maximum value (60.9%), followed by Gibe Awash (59.5%) ; however, both have low mean root biomass production (1.79 and 1.83 g/pot, respectively), although their value is a little bit higher than BHQPY545 (1.67 g/pot). The maximum mean root dry matter production was observed from BH547 (3.21 g/pot). All varieties performed well at pH 6.5. Lower pH values (below 4.8) severely reduced growth in all varieties. This study indicated the existence of difference among maize varieties for soil acidity stress and the negative effect of lower pH for maize growth. However, these results were based on pot experiment lacking yield data and not addressing all environmental factors, so their confirmation should be done by further similar field experiments across acid‐prone locations. Moreover, yield variables beyond this experiment should be included in a comprehensive manner to screen tolerant maize variety.