Effect of pH on germination and seedling growth of maize

Abstract

Soil pH is one of the most important limiting factors for crop cultivation, including maize. About 30-40% of the world's arable land is acidic, and over a billion ha is alkaline. Today, there are 205 million ha of arable land under maize in the world, so it ranks third in area after rice and wheat. Maize hybrids have wide genetic variability and high pH tolerance. We tested the tolerance of maize hybrids seedlings of ZP 4708 and ZP 5797 to pH 5, 6, 7, and 8. Results showed that hybrid ZP 4708 has a higher adaptability to low and high pH, due to the higher value of germination energy (GE), shoot length (ShL), shoot fresh weight (ShFW), shoot dry weight (ShDW), germination rate index (GRI), and seedling vigor index (SVI) than hybrid ZP 5797. Results further showed, on average for hybrids, that pH 5 and pH 8 significantly decreased the GE, root length (RL), ShL, root fresh weight (RFW), ShFW, root dry weight (RDW), shoot fresh weight (ShDW), and SVI. These parameters did not differ significantly between pH 6 and pH 7. Seed germination was not affected by the pH, indicating that the seed vigor of both hybrids supports full germination potential. However, it could be expected that exposure to the lowest and highest pH values of the medium could affect seedlings growth in the field conditions, even though germination is high. SVI showed a positive and significant correlation with all investigated parameters, except germination (G) and relative seedling water content (RSWC).