EFFECT OF HERBICIDES AND MICROELEMENTS ON RHIZOSPHERE MICROFLORA IN RELATION TO COTTON SEEDLING DISEASE CAUSED BY RHIZOCTONIA SOLANI (AG-4)

MAHMOUD, SAMY M. M.; RAGAB, MONA M.; SUMNER, DONALD R.; RAGAB, MAHMOUD M.

doi:10.21608/ejar.1995.433428

EFFECT OF HERBICIDES AND MICROELEMENTS ON RHIZOSPHERE MICROFLORA IN RELATION TO COTTON SEEDLING DISEASE CAUSED BY RHIZOCTONIA SOLANI (AG-4)

Document Type : Original Article

Authors

¹ Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt

² Department of Plant Pathology, Faculty of Agriculture, Cairo University, Giza, Egypt

³ University of Georgia, Coastal Plain Experiment Station, Tifton, GA 37793, U.S.A.

10.21608/ejar.1995.433428

Abstract

Greenhouse experiments with naturally infested field soil indicated that there was no interaction between the herbicides pendimethalin, fluometuron or norflurazon and the microelements manganese sulfate, sodium molybdate or sodium chloride on cotton stand and on the qualitative or quantitative status of rhizosphere microflora 14 and 28 days after planting (DAP). However, a significant interaction was found between herbicides and microelements on the emergence percentage 4 DAP and on the percentage of plants forming the first true leaf 11 DAP. Herbicides or microelements singly showed some influence on cotton stand and population of rhizosphere microflora depending on the treatment and the grCrup of microorganisms (fungi, bacteria or actinomycetes). The qualitative identification of rhizosphere was not affected within treatments. The herbicides pendimethalin and fluometuron decreased cotton stand 14 and 28 DAR but all the three herbicides increased percentage of moderately discolored roots and decreased the population of R.Solani (AG-4) in soil samples as compared with no herbicide treatment .