Permanent Link: http://ufdc.ufl.edu/IR00002877/00001
 Material Information
Title: Field Corn Nematode Management
Physical Description: Fact Sheet
Creator: Kinlock, Robert A.
Publisher: University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication: Gainesville, Fla.
Publication Date: 2001
Acquisition: Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status: Published
General Note: "Revised: December 2001."
General Note: "ENY-001"
 Record Information
Source Institution: University of Florida Institutional Repository
Holding Location: University of Florida
Rights Management: All rights reserved by the submitter.
System ID: IR00002877:00001

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ENY-001 Field Corn Nematode Management 1 Robert A. Kinloch and Jimmy R. Rich2 1. This document is Fact Sheet ENY-001, formerly RF-NG014, one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Revised: December 2001. Please visit the EDIS Web site at http://edis.ifas.ufl.edu. 2. Robert A. Kinloch, associate professor, Department of Entomology and Nematology, West Florida REC, Jay, FL and Jimmy R. Rich, professor, Department of Entomology and Nematology, North Florida REC, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Quincy, FL. The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean. Nematodes That Attack Field Corn Several nematode species are known to damage field corn in Florida. Most important is the sting nematode (Belonolaimus longicaudatus) whose distribution is limited to very sandy soils such as those typical of peninsular Florida. Stubby Root (Paratrichodorus spp.), lesion (Pratylenchus spp.), lance (Hoplolaimus spp.), and root-knot (Meloidogyne spp.) nematodes may also affect field corn growth. Yield reductions by most kinds of nematodes parasitizing field corn are usually severest in the sandiest soils and in times of drought. Generally, well-irrigated field corn overcomes nematode predation. Diagnosis Symptoms Above-ground symptoms of nematode injury include stunting, thin stands, premature wilting under moderate heat or drought stress, and nutrient deficiency symptoms. Since nematode numbers can vary greatly within very short distances in the field, areas of stunted growth, yield reduction, and other above-ground symptoms of nematode damage vary greatly in shape, size, and distribution. Symptoms and yield loss are worse in soils that are sandy, dry, and infertile. Roots injured by nematodes are usually stunted, often with few fine secondary feeder roots. Root tips may be blunt and swollen. Sometimes tufts of many stunted lateral roots emerge near the main root tips. By damaging root tips as soon as they emerge, nematodes can be especially injurious to young seedlings. Even under moderate stress, nematode-damaged roots may cause young plants to die, resulting in a thin crop stand. Nematode Assays Nematode problems of field corn can be determined only by nematode assay. Prior to taking samples, contact your county extension agent for information concerning available sampling tools, shipment bags and proper procedures for submitting samples. Samples should not be taken when the soil is dusty dry or soggy wet. Two sampling strategies may be employed. A general survey should be performed every three to four years and soil samples should be taken soon after field corn has been harvested. A soil core (1-inch wide by 8-10-inches deep) should be taken for every 2-3 acres in a 20-acre block containing a uniform soil type and cropping history. The cores should be thoroughly mixed and a 1-pint


Field Corn Nematode Management 2 sample extracted and placed in a sealed plastic bag and kept cool (not frozen) before immediate shipment to an advisory laboratory. In a more definitive strategy where a nematode problem is suspected, several soil cores from within and immediately around a poor growth site should be taken while the crop is still growing. Include portions of damaged roots with the soil sample. These samples should be processed as described above. Management Crop Rotation The worst nematode problems occur in fields where field corn and/or close relatives such as sorghum have been grown every year. Rotation to unrelated crops in successive years is usually better for all crops in the planting cycle, not just the cash crops for which crop rotations plans are primarily designed. Of all the agronomic crops commonly grown in rotation with field corn in Florida, peanut and tobacco are probably the best for reducing nematode pests of field corn. Nematicides Several nematicides have been approved for management of nematodes of field corn (Table 1). A recommendation for their use is problematic due to the low monetary profit from this crop. Currently, there is probably no financial justification for applying nematicides to field corn if the crop is being grown for forage. If an irrigated field realistically can be expected to produce a profitable seed yield, growers must consider that nematicides may only help recover some portion of the original potential yield that would be lost to nematodes.


Field Corn Nematode Management 3 Table 1. Nematicides that may be used for the management of nematodes on field corn. Nematicide1 Application1 Comment Counter CR 6 oz. / 1000 ft. row applied in a 7-inch band and incorporated before planting. Also registered for one post-emergence at the same rate if not previously applied. Do not exceed 6.5 lb. / acre, regardless of row spacing. Pesticide costs and commodity market expectations must be carefully considered before application of nematicides in field corn production. Mocap 10 G 18-21.5 oz. / 1000 ft. row in a 12-15 inch band and incorporated before planting. As above. Mocap 10 G Lock 'n Load 18-24 oz. / 1000 ft. row in a 12-15 inch band and incorporated before planting. As above. Telone II 26-35 fl. oz. / 1000 ft. of row/outlet via single chisel to a soil depth of 12-14 inches. As above. 1 Please consult labels for for pesticide handling and use restrictions.