IN FURROW TREATMENT OF FLORIDA STAYSWEET CORN FOR THE CONTROL OF PYTHIUM AND RHIZOCTONIA DAMPING-OFF

In spite of the many improvements in cultural practices to provide uniform corn production, pests still play havoc with plant stands and ultimately yields.
Field studies were conducted from 1980 thru 1983 at the Tropical Research and Education Center to use fungicides to control damp-off organisms and thereby improve plant stands.
Three fungi commonly found in South Florida soils, Pythium aphanidermatum (Eds.) Fitzp., P. debaryanum Hesse and Rhizoctonia solani Kuehn were the major cause of damp-off and root rot of germinating seed and young plants.
Form-A-Turf^R reduced losses in 1980, 81, 82, 83 by Pythium and Rhizoctonia. Metalaxyl applied in the furrow provided significant control of Pythium but not of Rhizoctonia. Captafol alone and in combination with Benomyl and Captan^R in combination with Benomyl provided control of Pythium and Rhizoctonia.

Maize, Z. mays, L. (Dent corn) and Z. mays L. var Saccharata (Sturtev.) Bailey (Sweetcorn) like most cultivated crops are not without thier disease problems (Stakman and Harrar 1954, Summer and Bell 1982). Without exception every part of the plant is attacked by at least one plant pathogen causing ear rot, leaf blight, root rot, rust, seed rot, smut, stalk rot, streak, stripe, stunt, and wilt (Chupp and Sherf 1960).

Sweet corn production in Florida on 60 000 acres has a dollar value of $64 745 000 (Florida Crop and Livestock Reporting Service 1983). Sweet corn is under cultivation throughout the year.
Winter production is on the Rockdale fine sandy loam rock complex and marl soils in Dade County Florida, continuing up both coasts on sandy soil as far north as Naples and Pompano.
Fall and spring corn production is found along the east coast from Pompano to Ft.
Pierce, the muck soils along the southeastern edge of Lake Okeechobee and the sandy muck soils along the northeastern edge of Lake Apopka.
Plant stand in the corn production areas can be reduced by as much as 50 percent by damping-off organisms depending on soil moisture and temperature.
Several fungi, Pythium spp., Fusarium moniliforme, and Rhizoctonia solani have been isolated frequently from diseased seedlings.
Seed companies treat the seed to reduce pathogen attack during storage (Christensen and Kaufman 1969, Christensen and Kaufman 1974, Moreno-Maartinez Vidal-Gaona 1981). To reduce the seed rots in the field seeds are routinely treated with a Captan dust or Captan slurry (Walker 1969). In Florida, sweet corn seeds are usually treated with Thiram (Fla.
Plant Disease Control 1985 Guide).

The research described here was designed to determine if any of the fungicides that have been proven effective for controlling Pythium spp. and Rhizoctonia solani on other crops would improve sweet corn stands.

Symposium on the Timing of Field Production of Vegetables

R.T. McMillan Jr

https://doi.org/10.17660/ActaHortic.1987.198.15