Presentation on theme: "Nematode Management in Florida Peanut Production"— Presentation transcript:
1Nematode Management in Florida Peanut Production Jimmy R. Rich NematologistJimmy Rich, Extension Nematologist-Agronomic Crops, University of Florida, IFAS/NFREC, 155 Research Road, Quincy, FL All comments for improvement would be greatly appreciated.
2Plant Nematode Characteristics Root parasites, mostly microscopicFive life stages (plus egg)Mostly wormlike, some females swollenLife cycle every daysFemale produces eggsOver one season 1 female = 8 Billion and more nematodes (hence the problem!!)Peanut root-knot nematodes, the major nematode parasites on peanut, reproduce every days in the summer and the females of these nematodes are swollen and immobile. The other major nematode parasite of peanut, lesion nematodes, remain wormlike and mobile throughout their life cycle.
3Nematodes, Highly Underrated Pests Most numerous animal in the worldAre the second most numerous animal speciesOver 6000 known plant-parasitic speciesNematodes attack all crop plantsPresent in greater than 90% of Florida fieldsThe Phylum Nematoda is composed of plant, animal and insect parasites. In addition, numerous free-living species exist, e.g. those that feed on soil flora and fauna and are considered beneficial.
4Nematode AnatomyThe nematode is a ‘ring’ nematode and generally not a problem in peanut production. However, it is illustrated here to show general nematode anatomy. Nematodes are considered ‘simple’ animals and lack a circulatory and skeletal systems.
5Plant-Parasitic Nematode Stylet (Spear) This is an actual stylet (spear) from a plant-parasitic nematode. Stylet parts include from left to right – stylet knobs, stylet shaft, and stylet extension.
6Nematodes Damaging Peanut Peanut Root-Knot Nematode:Causes 90% of nematode damageCauses galls on roots and podsLesion Nematode:Causes 10% of nematode damageEmerging problem after cotton and grass cropsNematode Names – Plant nematodes are generally given common names according to either damage symptoms they produce on plants or some striking morphological feature they possess. For example, root-knot nematodes produce root ‘knots’ while lesion nematodes cause ‘lesions’ on plant roots. The scientific names of the peanut root-knot and lesion nematodes are Meloidogyne arenaria and Pratylenchulus brachyurus, respectively.
7Root-Knot Nematode Life Stages Peanut root-knot nematodes are a key pest in the Florida peanut crop. The above photograph represents the gradual swelling of the second stage juvenile to become an immobile adult (juvenile stages 2 and 3 shown here).
8Female Root-Knot with Eggs, Root is the Size of a Pinhead The root-knot nematode adult female is encased inside the root gall. Unlike many nematodes, she gradually enlarges from penetration as a second-stage juvenile to the fifth stage adult. In this slide, the female and egg mass (left) have been stained red for easier viewing. In nature, the female and egg mass appear white to almost transparent. (Photo credit to the Society of Nematologists Slide Set Committee).
9Ways Root-Knot and Lesion Nematodes Affect Peanut Reduced nutrient and water uptake due to stunt plant rootsRedirected plant manufactured food resources for nematode growthPeanut peg abortion and poor development of surviving pegs/podsProviding an entrance for disease and pod-rotting organismsReducing nut quality hence final peanut gradesNematodes usually reduce root growth and function in most plants. Additional damage to peanut, however, occurs due to abortion of the developing pegs and poor quality nuts.
10Foliar Damage Symptoms Caused By Nematodes Premature wilting in spotsLeaf yellowingPlant stuntingIrregular (oval) symptom patternsPlant death at mid to late seasonFoliar Symptoms - Root feeding nematodes produce foliar symptoms that mirror root damage. In fact, most foliar-induced symptoms are the same as plants show when not receiving sufficient water and nutrients – wilting, yellowing, and stunting. As a result, nematode problems are often misdiagnosed and blamed on a lack of fertilizer and water.
11Root-Knot Nematode Damage Browning And Wilted Spots Root-knot nematodes may cause plant death, particularly from mid-season until harvest. At or near harvest is an excellent time to determine nematode damage and presence in a peanut field. Close inspection will provide greater accuracy for predicting future nematode problems than soil sampling.
12Root-Knot Damage Late Season Plant Death Root-knot nematode damage appears as more or less oval spots in a field. However, actual yield losses occur in areas much larger than the obvious ‘spots’.
13Root-Knot Nematode Damage Pod Galling and Rotting These are the pods that survived root-knot nematodes, most pods and pegs were aborted or rotted before harvest.
14Lesion Nematode - Plant Death is Seldom Evident Lesion nematode damage symptoms occurs in ‘spots’ in a field, however, these are generally more widespread than those caused by of root-knot nematodes.
15Lesion Nematode Damage A Dull Yellowing Lesion nematodes seldom cause widespread plant death but rather plant foliage shows a dull yellowing appearance. Foliar symptoms are often confused with nutrient deficiencies so roots and pods should be examined careful for signs of lesion nematode damage. CBR disease in peanut looks similar, however, the yellow color is much deeper and plants die quickly in those areas.
16Lesion Nematode Damage Brown Spots on Pods Presence of bright brown specks and spots on the peanut pod is indicative of lesion nematode presence. These pods show a moderate infection level of lesion nematodes, however, some losses occurred earlier due to peg abortion and decay of developing pods.
17Lesion Nematode Damage Brown Spots and Pod Rotting Lesions on the peanut eventually cover the whole pod and pod decay progresses.
18Know Your Nematodes For Accurate Management Decisions Each nematode species is ‘different’Management techniques should be ‘nematode species specific’Rotations must be planned for ‘key’ nematode pestsNematicide rates can be adjusted for individual nematode species
19Nematode Soil Samples Problem ID Take anytime during crop maturity and prior to planting, the best time is soon after harvestCan take these samples when collecting soil fertility samplesSplit soil samples, one for nematode analysis and one for fertility (1 pint each)Remember extra care is required for nematode samples
20Tools for Taking Nematode Soil Samples Choice of sampling toolsPlastic bagPermanent ink markerBucketThe sampling tool is not as important as obtaining good vertical slices of soil from the surface to 10-12” deep.
21Ten Acre Sampling Patterns (Take 15 To 20 Cores) Centered GridIntersected GridZig ZagRandomSoil samples to predict nematode problems in a following crop should be taken at or near crop harvest for best results, however, samples taken anytime are better than none at all. Take samples in moist soil to inches deep, mix sample, place a 1 pint subsample ina plastic bag and submit to the Extension Nematology laboratory via you local County Extension Office. Include roots as possible with the soil sample.
22Handling Nematode Soil Samples Sample 10-12” deep if possibleSample only in moist soils – Not dry or wetOnly use plastic bags to prevent soil dryingDo not allow samples to become hot or coldRemember, nematodes are living animals, treat samples gentlyNematodes are quite fragile and can be killed through rough handling of soil, high or very low temperatures and from desiccation. Dead nematodes decay rapidly and are not recovered during soil extraction in the laboratory.
24Peanut Nematicides Only a Few Choices!! Telone II - Dow AgroSciencesTemik 15G - Bayer CropScienceNemacur - Bayer CropScience(cancellation notice for 2007)By mutual agreement of EPA and Bayer CropScience, all uses of Nemacur will be cancelled in 2007.
25Telone II Product Information Sold as liquid formulation onlyMovement by fumigant action in the soilApplied preplant injected to 14 inches depth (do not apply in clay subsoil)May be applied as a single in-row chisel, dual chisels or broadcastTelone II kills nematodes on contactThe ability of Telone II to move in soil by vaporization and nematode death on contact make it the most effective nematicide for nematode control in peanut. Non-fumigant nematicides provide somewhat variable nematode control due to the need to move in soil water andMainly just paralyzing rather than outright killing nematodes.
26Temik 15G Product Information Sold only as a 15% granular formulationFormulation may be corncob (lighter) or clay basedUsed at-planting as a band or in-furrow treatmentMay be applied as an at-pegging time treatment
27Telone and Temik Are Restricted Use Pesticides Reminder - both products have specific use restrictions!!Temik has special reporting and use requirements in FloridaTemik 15G forms and other requirements can be found at FDACS Web Site -
28Nematicide Recommendations High nematode levels or continuous peanut: Telone II at 6 gal./A + Temik 15G at 10 lb./A (at pegging)Moderate nematode levels: Telone II at 6 gal./A or Temik 15G at 10 lb./A (at planting) and Temik at 10 lb./A (at pegging)Low nematode levels: Temik 15G at 7-10 lb./A (at planting)These nematicide recommendations are based on the peanut root-knot nematode. Lesion nematodes require nematicides but at lower rates than root-knot nematodes. Low, moderate and high nematode levels are relative terms. The actual number of nematodes extracted from a soil sample and prediction of damage must be used in conjunction with the time of year the sample was taken, future crop susceptibility, and past cropping history.
29‘Other’ Nematicides Mocap - Bayer CropScience Counter - BASF Furadan - FMCVapam - AmVac CorporationChlor-O-Pic - Hendrix and DialNematicide registrations may change so please consult labels before using these materials. These ‘other nematicides’ can be used but are recommended only for special circumstances in Florida peanut.
30Center Untreated Strip Telone II Applied on Either Side This 100 acre field had been continuously cropped to peanut for about 8 years and heavily infested with peanut root-knot nematodes. By harvest, few plants in the untreated strip were alive. Yields were 700 lbs. per acre in the untreated strip and 2500 lbs per acre in the Telone II treatment.
31Telone Treatment (Background) and Untreated Control (Foreground) Pictured is Bill Smith, Columbia County Extension Agent who initiated this Telone demonstration in the grower field.
32Peanut Resistance/Tolerance No commercially adapted varieties to Florida production conditionsActive pursuit of root-knot nematode resistance is being made in Florida peanut breeding programsEarly data indicate some tolerance to nematode damage in some varieties: Southern Runner, AP3, Hull, and DP1The Texas A&M peanut breeding program has release a root-knot nematode resistance runner variety, NEMATAM, later replaced by COAN. These varieties exhibit good resistance to the peanut root-knot nematode, however, they lacks adequate resistance to common fungal and viral diseases prevalent in Florida peanut. Crosses of these varieties with varieties adapted to Florida are progressing well.
33Sanitation NotesPrevent crop regrowth (peanut, cotton) to stop nematode population increase in the fallControl of nematode host weeds including morningglories, florida pusley, tropical spiderwort, and nutsedgeImplement perennial grass rotation (bahiagrass) with good weed controlFall and spring growth of weeds and volunteer peanuts maintains and sometimes increases nematode populations, hence problems in future crops. Planting bahiagrass without follow-up weed control limits the effectiveness of this rotation for nematode management.
34Sanitation - Prevent Volunteer Peanut Growth Volunteer peanuts may allow one or more additional generations of nematodes in the fall after harvest. Also, volunteer peanuts the following year will maintain or increase nematode populations.
35Weed Hosts of Nematodes in Bahiagrass Pasture If weed hosts to nematodes are allowed to grow, rotations lose much of their value in reducing nematode damage to following crops.
36Crop Rotations to Manage Nematodes in Peanut Plan rotations to manage the peanut root-knot nematode, the ‘key’ nematode pest on peanutLesion nematodes are less damaging to peanut but rotation is difficult due to wide host rangeHence, nematicidal control may be needed for lesion nematodes, but at lower rates than for root-knot
37Crop Rotation to Reduce Peanut Root-Knot Nematodes Grass crops are the best for reducing root-knot nematode problemsAmong the grass crops, bahiagrass is a non-host and provides other good advantages as wellCotton is an excellent rotation crop for managing the peanut root-knot nematode
38Crop Rotation to Reduce Lesion Nematodes It is difficult to reduce lesion nematodes using crop rotationsLesion nematodes reproduce well on most grass cropsBahiagrass is a non-hostCotton, tobacco and soybean are moderate hosts
40FAQ – My Bahiagrass Rotation did not Prevent Nematode Damage? Bahiagrass is non-host for root-knot and lesion nematodes, but the rotation is not perfect:Length of bahiagrass rotation must generally be a minimum of three yearsWeed Management is sometimes more important than rotation length with bahiagrassWeed hosts of nematodes in bahiagrass must be controlled or nematodes remain to damage a future peanut crop
41FAQ - What About GPS/GIS Variable Rate Nematicide Application? This technology is available, however, the economics are still uncertain?System Needs:Accurate nematode population distribution map of a field, alternatively, a yield monitor map linked to nematode populationsGPS unit programmed for nematicide rate based on the nematode distribution mapEquipment suitable for nematicide rate adjustment
42Root-Knot Nematode Numbers in a 100 Acre Field 2.5 Acre Grid Pattern,Nematodes/ ¼ Pint SoilThis field was contained high levels of root-knot nematodes. Colors indicate the use of variable rates of nematicide (Telone II) as follows: Green – no nematicide, Yellow – low nematicide rate, Orange – moderate nematicide rate, Red – high rates.
43For More InformationVisit the UF/IFAS EDIS Web Site atSearch ‘Peanut Nematodes’