The Effect of Al and Mg on the Transpiration Rate of Young Maize Plants

Abstract

In a nutrient solution experiment with two Al (0 and 0.1 mM) combined with two Mg treatments (0.1 and 0.5 or 0.75 mM resp.) Al induced Mg deficiency in maize. Growth of maize responded to Mg only in the presence of Al, but did not attain the same level as without Al. Without Al in the nutrient solution 0.1 mM Mg was adequate. Contrary to growth the transpiration rate per unit leaf area was increased at the higher Mg concentration irrespective of the absence or presence of Al but was at an overall lower level in the latter case. It is assumed that Al acted through reducing Mg uptake and impeding root function with respect to water uptake.

Aluminum-induced growth stimulation in relation to calcium, magnesium, and silicate nutrition inMelastoma malabathricumL.

“…1 and 2), Ca or Mg application effects were significant in the + Al treatment, indicating that Ca or Mg application alleviated the Al toxicity (Hecht-Buchholz and Schuster 1987; Grimme and Lindhauer 1989;Shen et al 1993). In barley, the alleviation of Al toxicity by Ca or Mg was hardly observed, suggesting that 0.5 mM Al is an excessive amount for the inhibition of growth.…”

“…The Al effect on nutrient uptake, especially competitive inhibition of Ca and Mg uptake has been thoroughly studied (Rengel and Robinson 1989;Huang et al 1992;Rengel and Elliott 1992;Ding et al 1993). Since Al toxicity is alleviated by the increase of Ca and Mg application (Grimme and Lindhauer 1989;Shen et ai. 1993), it is assumed that Al toxicity is due to the inhibition of Ca or Mg uptake by AI.…”