Cotton response to iron sources on calcareous soil

Abstract

Abstract Many crops grown on calcareous soils exhibit Fe deficiency symptoms to varying degrees. Cotton (Gossypium hirsutum L.) is generally considered a more efficient utilizer of Fe than plants such as sorghum, and therefore has received less attention in Fe nutrition research. Observed reductions in plant growth and disease association in areas where indicator sorghum crops showed moderate to severe Fe deficiency chlorosis gave impetus to this study. Cotton was grown on three soils rated slight, moderate, and severe in Fe deficiency. The three soils had histories of producing sorghum with Fe deficiency chlorosis varying from slight to severe. Cotton grown on two of the soils exhibited slight to severe Phymatotrichum root rot disease. Chelate extractable Fe (DTPA) correlated positively with dry matter and lint production in the greenhouse for the three soils. Although interveinal chlorosis was not evident on cotton grown on the three soils, a slight variation in green color of foliage was observed depen...