Band Application of Sulfuric Acid or Elemental Sulfur for Control of Fe-Deficiency Chlorosis of Soybeans1
- S. J. Frank and
- W. R. Fehr2
Iron-deficiency chlorosis can reduce the productivity of susceptible soybean [Glycine max (L.) Merr.] cultivars when grown on certain calcareous soils. Two experiments were conducted to evaluate the use of S and sulfuric acid (H2SO4) for the control of Fe-deficiency chlorosis of soybeans grown on calcareous Harps (fine-loamy, mesic, Typic Calciaquoll) soils in the field. In Exp. 1, H2SO4 was applied at eight rates from 0 to 123.5 g/m of row at two depths under the seed, 2.5 and 5 cm. Two cultivars susceptible to Fe-deficiency chlorosis, ‘Corsoy’ and Pride ‘B216’, were evaluated with each rate in five Iowa environments during 1978 and 1979. In Exp. 2, H2SO4 was applied 5 cm below the seed at the same rates as in Exp. 1, and S was applied at the same depth as a powder at rates equivalent to the amount of S applied in the H2SO4. Corsoy and B216 were evaluated with both chemicals on calcareous soils in four Iowa environments during 1979. Response in both experiments was evaluated by visual chlorosis ratings before flowering, and also by plant height at maturity in Exp. 1. Sulfuric acid significantly reduced chlorosis and increased plant height for both cultivars and depths of placement at the rates of 30.9, 61.8, and 123.5 g/m when averaged across environments. Only at the 123.5 g/m rate did placement of the H2SO4 5 cm below the seed cause a significantly greater reduction in chlorosis score and increase in height than at the 2.5-cm depth. None of the H2SO4 treatments completely prevented chlorosis in either cultivar. Application of S did not cause significant reduction in chlorosis scores at any of the rates usedPlease view the pdf by using the Full Text (PDF) link under 'View' to the left.
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