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Improved Fungicide Efficacy on Canola through Application Technology

 

Scott Halley* and John Lukach

Langdon Research Extension Center, North Dakota State University, Langdon, ND 58249,

*Corresponding Author: PH: (701) 256-2582, E-mail: shalley@ndsuext.nodak.edu

 

A research trial was conducted in 2002 and 2003 to evaluate fungicide spray application technology with Ronilan (vinclozolin) fungicide for control of white mold, Sclerotinia sclerotiorum (Lib) de Bary, in canola. A split split plot design (2 x 3 x 3) compared early and late planting date and three sprayer systems; a conventional type equipped with hydraulic nozzles oriented vertical; a modified Spray-air� sprayer with an air-assisted spray distribution system oriented vertically down; and a Spray-air oriented forward and backward. The conventional spray system uses CO2 to deliver the solution through a XR8002 flat fan nozzle spaced 20 inches on center at 40 psi. The Spray-air system also used CO2 to deliver the solution through an orifice. An air stream, created by a hydraulically driven centrifugal fan, picks up the solution, creates a drop using air shear technology, and delivers the fungicide to the target through orifices spaced 10 in apart. The system was modified from original equipment specifications to spray at an angle 30� downward from horizontal and optionally forward and backward. Spray volumes of 5.2, 10.4, and 19.2 GPA were the third set of factors and were adjusted by tractor travel speed.

 

Materials and Methods

 

The sites, previous crop barley both years, were planted with a double disk drill, disks spaced 6 inches, to plots 7 rows wide 16 ft long. An additional border area 6.5 ft wide was planted between plots to accommodate the tractor travel, to reduce drift to adjacent plots, and to create a field type environment conducive to white mold disease development. Cultivars �InVigor 2733� and �Hyola 357 Magnum� were planted on 14 May and 30 May 2002 and 13 May and 2 Jun 2003, respectively. Recommended production practices for Northeast North Dakota, NDSU Extension, were followed. Two inoculation techniques were used to improve chance of white mold infections. In 2002 sclerotia were hand broadcast and shallowly incorporated in spring after conditioning by three in vitro freeze/thaw cycles of 14 days duration each. This conditioning technique was modified in 2003. Sclerotia were blended with soil to achieve a 50% soil/sclerotia mix by volume and 30% water by weight was added before a single in vitro freeze cycle of 6 weeks. In 2003 the conditioned sclerotia were hand broadcast and shallowly soil covered both in fall and spring before seeding to increase potential for white mold infection. The 2003 technique was more effective in producing apothecia throughout the growing season than the 2002 technique.

 

Ronilan fungicide was applied at 12 oz/acre. Fungicide was applied on 2 and 16 Jul and 1 and 19 July in 2002 and 2003, respectively, at 30% bloom stage of growth.In 2003 Day-Glo orange fluorescent dye was added to the spray solution at 1.75% v/v to measure fungicide coverage on the flowers. Compatibility of the fungicide and the dye were determined by Surinam Panigrahi, NDSU Ag Engineering and Biosystems Department the previous winter. A second technique was implemented inn both growing seasons to increase chance of white mold infection. On 1 and 16 Jul 2002 and 6 and 24 Jul 2003, ascospores at 5000 spores/ml were sprayed by backpack sprayer at 9.2 GPA and 40 psi at 30 to 50% bloom growth stage. A later than expected delivery date of the digital camera coupled with a software problem did not permit collection of spray coverage data in 2002. Flowers were clipped, bagged, and transferred to cold storage. As soon as fungicide applications concluded, an Optronics CCD digital video camera was used to photograph the flowers under incandescent light, to determine the area of the target, and under ultraviolet light to determine the area covered by the spray solution. The target, fresh canola flowers, disintegrated almost immediately after removal from the plant. No usable data was collected on spray coverage from the early plant timing. Following fungicide application, late plant 2003, leaves in the lower canopy were collected and spray coverage was determined by procedure described previously. Infection due to white mold disease was determined by counting two rows 16 ft long and individually giving each plant 0, 0.5, 1 where 0=no visible disease, 0.5=infection of one or more branches, 1=infection of main stem. Plots were swathed and harvested after dry down.The seed sample was cleaned and processed to determine yield and test weight. Additionally, oil and thousand seed weight (TSW) were measured in 2002. Data were analyzed with the general linear model (GLM) in SAS. Least significant differences (LSD) were used to compare means at the 5% probability level.

 

Results and Discussion

 

Increases in yield and test weight by plant date (Table 3) and a reduction in sclerotinia by plant date, 2003 (Table 7), were measured. Additionally, a difference in thousand seed weight by plant date, sprayer system, and GPA was also detected (Table 6). No differences in leaf coverage were detected.

 

The study brought to attention several of the difficulties in doing sclerotinia research. Successes in achieving desired levels of white mold infections in other trials were achieved with supplemental water applications to the soil and crop canopy. Water applied to the soil before flowering enhanced carpogenetic germination of the sclerotia. Supplemental water at flowering promoted an environment conducive to disease infection. Watering systems currently used in other studies would be difficult to use with tractor mounted application technology studies. A small wheel irrigation unit will need to be acquired for future fungicide application technology trials utilizing tractor spray systems. The canola flower deteriorated rapidly after removal from the plant. Further deterioration was accelerated by the heat generated by the lights of the camera system. A portable video imaging unit to collect and record the data while the flower is intact on the plant in the field is needed and has been proposed by Dr. Suranjan Panigrahi of NDSU Ag Engineering and Biosystems Department. I will look forward to working with him on projects when the technology is available for field use. Large areas of the leaves in the lower canopy received little or no fungicide from the spray application. The probable cause was interference from other plant structures, leaves and stems. It is probable that when later emerging flowers senesce and fall, infections can and will occur.Research studies should be undertaken to address these issues.

 

 

 

 

 

Table 1. Yield and test weight by year, plant date, sprayer system, and GPA.

Plant Date

Sprayer System

GPA1

Yield

Test Weight

 

 

 

bu/A

lb/bu

2002

 

 

 

 

Early

 

 

 

 

 

Conventional Down

5.2

1235

50.1

 

 

10.4

1072

49.2

 

 

19.2

1273

49.8

 

Spray-Air Down

5.2

1415

49.8

 

 

10.4

1418

49.8

 

 

19.2

1118

50.3

 

Spray-Air F+B

5.2

1030

50.0

 

 

10.4

1305

49.8

 

 

19.2

1312

50.0

Late

Conventional Down

5.2

1243

51.1

 

 

10.4

1265

51.0

 

 

19.2

1113

50.6

 

Spray-Air Down

5.2

1022

51.0

 

 

10.4

1250

51.1

 

 

19.2

1240

50.4

 

Spray-Air F+B

5.2

1243

51.0

 

 

10.4

1153

51.0

 

 

19.2

1148

50.6

2003

 

 

 

 

Early

Conventional Down

5.2

1955

51.9

 

 

10.4

1927

51.8

 

 

19.2

2208

51.8

 

Spray-Air Down

5.2

1896

51.5

 

 

10.4

2192

52.1

 

 

19.2

1939

51.8

 

Spray-Air F+B

5.2

2139

51.4

 

 

10.4

2050

51.9

 

 

19.2

2060

52.1

Late

Conventional Down

5.2

1633

52.3

 

 

10.4

1574

52.3

 

 

19.2

1633

52.5

 

Spray-Air Down

5.2

1564

52.4

 

 

10.4

1561

52.3

 

 

19.2

1567

52.6

 

Spray-Air F+B

5.2

1615

52.6

 

 

10.4

1684

52.3

 

 

19.2

1522

52.5

1Gallons per acre

 

 

 

Table 2. Yield and test weight by plant date and sprayer system by year, plant date and GPA by year, and GPA by year.

Plant Date

Sprayer System

GPA1

Yield

Test Weight

 

 

 

bu/A

lb/bu

Plant date by sprayer system averaged across GPA

 

 

2002

 

 

 

 

Early

Conventional Down

 

1193

49.7

 

SprayAir Down

 

1317

49.9

 

SprayAir F + B

 

1216

49.9

Late

Conventional Down

 

1207

50.9

 

SprayAir Down

 

1171

50.8

 

SprayAir F + B

 

1181

50.9

2003

 

 

 

 

Early

Conventional Down

 

2030

51.8

 

SprayAir Down

 

2009

51.8

 

SprayAir F + B

 

2083

51.8

Late

Conventional Down

 

1613

52.3

 

SprayAir Down

 

1564

52.4

 

SprayAir F + B

 

1607

52.5

Plant date by GPA averaged across sprayer systems

 

 

2002

 

 

 

 

Early

 

5.2

1227

50.0

 

 

10.4

1265

49.6

 

 

19.2

1234

50.0

Late

 

5.2

1169

51.0

 

 

10.4

1223

51.0

 

 

19.2

1167

50.5

2003

 

 

 

 

Early

 

5.2

1997

51.6

 

 

10.4

2056

51.9

 

 

19.2

2069

51.9

Late

 

5.2

1604

52.4

 

 

10.4

1606

52.3

 

 

19.2

1594

52.5

LSD

 

 

 

 

 

 

 

GPA averaged across plant dates and sprayer systems

 

 

2002

 

5.2

1198

50.5

 

 

10.4

1244

50.3

 

 

19.2

1200

50.3

2003

 

5.2

1800

52.0

 

 

10.4

1831

52.1

 

 

19.2

1822

52.2

1Gallons per acre

 

 

Table 3.Yield and test weight by year, sprayer system, and GPA, plant date by year, and sprayer system by year.

Plant Date

Sprayer System

GPA1

Yield

Test Weight

 

 

 

bu/A

lb/bu

Sprayer system by GPA averaged across plant dates

 

 

2002

Conventional Down

5.2

1239

50.6

 

 

10.4

1168

50.1

 

 

19.2

1193

50.2

 

Spray-Air Down

5.2

1219

50.4

 

 

10.4

1334

50.4

 

 

19.2

1179

50.3

 

Spray-Air F+B

5.2

1136

50.5

 

 

10.4

1229

50.4

 

 

19.2

1230

50.3

2003

Conventional Down

5.2

1794

50.1

 

 

10.4

1750

52.0

 

 

19.2

1920

52.1

 

Spray-Air Down

5.2

1730

51.9

 

 

10.4

1877

52.2

 

 

19.2

1753

52.2

 

Spray-Air F+B

5.2

1877

52.0

 

 

10.4

1867

52.1

 

 

19.2

1791

52.3

Plant date averaged across sprayer systems and GPA

 

 

2002

 

 

 

 

Early

 

 

1242

49.8

Late

 

 

1186

50.9

2003

 

 

 

 

Early

 

 

2041

51.8

Late

 

 

1595

52.4

LSD

 

 

207

0.5

Sprayer system averaged across plant dates and GPA

 

 

2002

Conventional Down

 

1200

50.3

 

SprayAir Down

 

1244

50.4

 

SprayAir F + B

 

1198

50.4

2003

Conventional Down

 

1822

52.1

 

SprayAir Down

 

1786

52.1

 

SprayAir F + B

 

1845

52.1

1Gallons per acre

 

 

 

 

 

 

 

Table 4. Yield and test weight by plant date, sprayer system, GPA, plant date by sprayer system, sprayer system by GPA, and plant date by GPA.

Plant Date

Sprayer System

GPA1

Yield

Test Weight

 

 

 

bu/A

lb/bu

Plant date averaged across sprayer systems and GPA

 

 

Early

 

 

1641

50.8

Late

 

 

1390

51.6

Sprayer system averaged across plant dates and GPA

 

 

 

Conventional Down

 

1511

51.2

 

SprayAir Down

 

1516

51.2

 

SprayAir F + B

 

1522

51.3

GPA averaged across sprayer systems and plant dates

 

 

 

 

5.2

1499

51.3

 

 

10.4

1537

51.2

 

 

19.2

1511

51.2

Plant date by sprayer system averaged across GPA

 

 

Early

Conventional Down

 

1611

50.7

 

SprayAir Down

 

1663

50.9

 

SprayAir F + B

 

1649

50.9

Late

Conventional Down

 

1410

51.6

 

SprayAir Down

 

1367

51.6

 

SprayAir F + B

 

1394

51.7

Sprayer system by GPA averaged across plant dates

 

 

 

Conventional Down

5.2

1516

51.4

 

 

10.4

1459

51.0

 

 

19.2

1556

51.2

 

SprayAir Down

5.2

1474

51.2

 

 

10.4

1605

51.3

 

 

19.2

1466

51.3

 

SprayAir F + B

5.2

1507

51.3

 

 

10.4

1548

51.2

 

 

19.2

1510

51.3

Plant date by GPA averaged across sprayer systems

 

 

Early

 

5.2

1612

50.8

 

 

10.4

1661

50.7

 

 

19.2

1652

50.9

Late

 

5.2

1387

51.7

 

 

10.4

1414

51.6

 

 

19.2

1370

51.5

1Gallons per acre

 

 

 

 

 

 

Table 5. Yield and test weight averaged over plant dates, sprayer systems, GPA, and years and untreated averaged over plant date and year.

Plant Date

Sprayer System

GPA1

Yield

Test Weight

 

 

 

bu/A

lb/bu

 

 

 

 

 

Early

Conventional Down

5.2

1595

51.0

 

 

10.4

1499

50.5

 

 

19.2

1740

50.8

 

SprayAir Down

5.2

1655

50.6

 

 

10.4

1805

50.9

 

 

19.2

1528

51.0

 

SprayAir F + B

5.2

1585

50.7

 

 

10.4

1678

50.8

 

 

19.2

1686

51.1

Late

Conventional Down

5.2

1438

51.7

 

 

10.4

1419

51.6

 

 

19.2

1419

51.6

 

SprayAir Down

5.2

1373

51.7

 

 

10.4

1293

51.7

 

 

19.2

1405

51.5

 

SprayAir F + B

5.2

1403

51.8

 

 

10.4

1429

51.6

 

 

19.2

1335

51.6

 

 

 

 

 

2002 Untreated

 

 

 

Early

 

na

1470

50.0

Late

 

na

1170

50.6

2003 Untreated

 

 

 

Early

 

na

2001

51.6

Late

 

na

1636

52.4

1Gallons per acre

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 6, Sclerotinia, thousand seed weight, oil, and coverage, 2002 or 2003 as applicable, by plant date, sprayer system, and GPA, plant date and sprayer system, or plant date and GPA.

Plant Date

Sprayer System

GPA1

Sclerotinia

TSW2

Oil

 

 

 

plants/row

g

%

 

 

 

 

 

 

Early

Conventional Down

5.2

3.9

3.5

44.5

 

 

10.4

3.5

3.5

45.6

 

 

19.2

3.3

3.5

45.2

Late

Conventional Down

5.2

0.3

3.0

42.0

 

 

10.4

2.0

3.4

43.8

 

 

19.2

1.5

3.1

43.9

Early

Spray-Air Down

5.2

4.0

3.4

43.6

 

 

10.4

2.3

3.5

44.8

 

 

19.2

2.5

3.4

44.3

Late

Spray-Air Down

5.2

1.5

3.1

42.8

 

 

10.4

0.9

3.2

43.8

 

 

19.2

1.1

3.5

44.0

Early

Spray-Air F+B

5.2

5.0

3.5

45.0

 

 

10.4

5.6

3.7

45.0

 

 

19.2

1.6

3.4

45.0

Late

Spray-Air F+B

5.2

1.8

3.4

43.8

 

 

10.4

1.3

3.2

43.5

 

 

19.2

1.1

3.5

43.7

 

 

 

 

 

 

Sprayer systems by plant dates averaged across GPA

 

 

Early

Conventional Down

 

3.5

3.5

45.1

Late

 

 

1.3

3.2

43.2

Early

Spray-Air Down

 

2.9

3.4

44.2

Late

 

 

1.2

3.3

43.5

Early

Spray-Air F+B

 

4.1

3.5

45.0

Late

 

 

1.4

3.3

43.7

 

 

 

 

 

 

Plant dates by GPA averaged across spraying systems

 

 

Early

 

5.2

4.3

3.4

44.3

 

 

10.4

3.8

3.6

45.1

 

 

19.2

2.5

3.5

44.8

Late

 

5.2

1.2

3.2

42.9

 

 

10.4

1.4

3.3

43.7

 

 

19.2

1.3

3.3

43.9

1Gallons per acre

2Thousand seed weight


Table 7. Sclerotinia, thousand seed weight, oil, and coverage, by sprayer system and GPA, sprayer system, plant date, GPA, and untreated by plant date and year.

Plant

Sprayer System

GPA1

Sclerotinia

TSW2

Oil

Coverage

 

 

 

plants/row

g

%

%

Spraying systems by GPA averaged across plant dates

 

 

 

 

Conventional Down

5.2

2.1

3.2

43.2

1.8

 

 

10.4

2.8

3.4

44.7

1.8

 

 

19.2

2.4

3.3

44.6

1.6

 

Spray-Air Down

5.2

2.8

3.2

43.2

1.1

 

 

10.4

1.6

3.4

44.3

1.5

 

 

19.2

1.8

3.5

44.1

2.2

 

Spray-Air F+B

5.2

3.4

3.4

44.4

2.7

 

 

10.4

3.4

3.4

44.2

1.9

 

 

19.2

1.4

3.4

44.4

1.8

 

 

 

 

 

 

 

Spraying systems averaged across plant dates and GPA

 

 

 

 

Conventional Down

 

2.4

3.3

44.2

1.8

 

SprayAir Down

 

2.0

3.4

43.9

1.6

 

SprayAir F + B

 

2.7

3.4

44.3

2.1

 

 

 

 

 

 

 

Plant dates averaged across spraying systems and GPA

 

 

 

Early

 

 

3.5

3.5

44.8

 

Late

 

 

1.3

3.3

43.5

 

 

 

 

 

 

 

 

GPA averaged across spraying systems and plant dates

 

 

 

 

 

5.2

2.7

3.3

43.6

1.9

 

 

10.4

2.6

3.4

44.4

1.9

 

 

19.2

1.9

3.4

44.4

1.7

2002 Untreated

 

 

 

 

 

Early

 

na

na

3.4

45.0

na

Late

 

na

na

3.2

43.5

na

2003 Untreated

 

 

 

 

 

Early

 

na

6.1

na

Na

na

Late

 

na

3.0

na

Na

na

1Gallons per acre

2Thousand seed weight

 

 


Table 8.Analysis of variance (P values) of yield and test weight averaged over years and thousand seed weight, oil, sclerotinia rating and coverage by respective year.

Model

df

Yield

Test Weight

Model

df

TSW1

Oil

Sclerotinia

Coverage

 

 

P > F

P > F

 

 

P > F

P > F

P > F

P > F

 

 

 

 

 

 

 

 

 

 

Year (Yr)

1

0.0001

0.0001

 

 

 

 

 

 

Rep (yr)

1

0.0002

0.0215

Rep

3

0.0066

0.0392

0.7214

 

PlantDate (PD)

1

0.4209

0.1615

Plant Date (PD)

1

0.1128

0.0685

0.0404

 

Y*PD

2

0.0174

0.0301

 

 

 

 

 

 

Sprayer System (SS)

2

0.9704

0.0617

Sprayer System(SS)

2

0.0932

0.4133

0.6169

0.4101

Yr*SS

2

0.4673

0.9800

 

 

 

 

 

 

PD*SS

2

0.4127

0.7867

PD*SS

2

0.3134

0.3530

0.7073

 

Yr*PD*SS

24

0.6632

0.5576

 

 

 

 

 

 

GPA2

2

0.1565

0.9222

GPA

2

0.1216

0.1067

0.2769

0.9278

Yr*GPA

2

0.9321

0.1943

 

 

 

 

 

 

PD*GPA

2

0.4272

0.7458

PD*GPA

2

0.2923

0.7851

0.2545

 

Yr*PD*GPA

2

0.8617

0.0298

 

 

 

 

 

 

SS*GPA

4

0.2817

0.6221

SS*GP

4

0.3026

0.4933

0.3119

0.3386

Yr*SS*GPA

4

0.5981

0.9742

 

 

 

 

 

 

PD*SS*GPA

4

0.4375

0.3994

PD*SS*GPA

4

0.0127

0.9595

0.5719

 

Yr*PD*SS*GPA

4

0.1401

0.6928

 

 

 

 

 

 

1Thousand seed weight

2Gallonage