Selected soil-borne fungi under glyphosate application and crop residues from a long-term field experiment.

JOSÉ MERILES; SILVINA VARGAS GIL; RICARDO HARO; GUILLERMO MARCH; CARLOS GUZMÁN

BIOLOGICAL AGRICULTURE & HORTICULTURE

A B ACADEMIC PUBL

Año: 2008 vol. 26 p. 193 - 205

0144-8765

A study was carried out to determine the short-term effects of glyphosate and crop residueson the population dynamics of soil-borne fungi under field conditions. Field experiments wereconducted during two growing seasons. The assays were done in plots that were subjected to apeanut (Arachis hypogaea)-corn (Zea mays)-soyabean (Glycine max) rotation system with twosequences: corn-soyabean-peanut and soyabean-corn-peanut. Soil samples were randomly collectedfrom a peanut-corn-soyabean rotation field located at Córdoba province (Argentina) in order toquantify native populations of Fusarium, Pythium, Trichoderma, Gliocladium and culturable totalfungi populations. Independently of the present crop, the highest population of Trichodermaand Gliocladium were recorded in soil with corn residue. Pythium populations increased afterglyphosate treatment. Trichoderma, Gliocladium and culturable total fungi populations were notaffected by glyphosate applications. Information on the actual time and duration of populationresponses of various important soil-borne fungi after glyphosate treatment is currently limitedsince it is dependent on numerous parameters such as soil condition, type of hosts involvedand soil microbial interactions. The use of corn residue appeared as an interesting alternative toincrease the population of potential antagonistre fungi, and reduce crop diseases; therefore morefield research along this line is clearly needed.