EFFECTS OF ARBUSCULAR MYCORRHIZAL FUNGUS ON DRY-MATTER YIELD, AS WELLAS P-CONCENTRATIONS AND K-CONCENTRATIONS IN MAIZE (ZEA-MAYS L) AT INCREASING LEVELS OF P SUPPLY

The effect of mycorrhizal inoculation, Glomus sp. D13 (originated from Hannover), on the growth response as well as P and K uptake of maize (Zen mays L.) was tested. The greenhouse experiment was conducted at f ive levels of P fertilization (0, 21.5, 43, 64.5, and 86 mg P/kg soil) . At 49 days after planting, the colonization ranged from 20 to 24% of the total root length in inoculated plants and there was no colonizat ion in noninoculated plants. Three weeks later, at harvest, colonizati on ranged from 20 to 35% in inoculated plants and 0 to 3% in noninocul ated plants. The root length of mycorrhizal plants remained lower, but insignificant, than that of nonmycorrhizal plants. The root dry weigh t was increased with increasing levels of P application in both treatm ents. The root dry weights of control plants were significantly higher than those of the respective mycorrhizal plants at all levels of appl ied P. Shoot dry weight increased until P2 and P3 levels in inoculated and noninoculated plants respectively. In mycorrhizal treatment, tota l uptake of P (as well as P concentrations in roots and shoots) was in creased as was the uptake of K. The K concentration in shoots of mycor rhizal plants was also higher than that of nonmycorrhizal plants, wher eas the root K concentrations of inoculated and noninoculated plants d id not vary when P was applied.