Crop-Adapted Spraying optimizing orchard pesticide rates. Dr. Jason Deveau OMAFRA Application Technology Specialist Winter 2015

Transcription

1 Crop-Adapted Spraying optimizing orchard pesticide rates Dr. Jason Deveau OMAFRA Application Technology Specialist Winter 2015

2 Working to reduce pesticide wastage and off-target contamination Developing methods to spray crops consistently Developing educational resources for sprayer operators

3 Most pesticide label rates reflect the area of the planting (e.g. L/ha), not the area-density of the plant canopy A fixed, prescribed spray volume and/or rate is insufficient to match orchard variability An hectare of corn is a hectare of corn, but a hectare of apple trees

4 Which tree is bigger? Imagine plucking every leaf from each tree and laying them out like a sheet Which tree has more surface area?

5 Planting area doesn t represent canopy Quote me: It s not just the size of the box, it s what s in the box!

6 Inter-orchard variability 3 English apple orchard canopies measured at the same time of season: 8,500 to 19,000 m 3 /ha (2001) This is due to variety, growth stage, root stock, tree shape, planting density, row spacing & pruning practices So, should rates be expressed strictly by planting area?

7 Intra-orchard variability New Zealand apple canopies ranged from 10,000 to 40,000 m 3 /ha and increased by 30% over season (1997) U.K. studies demonstrated that a fixed rate at different growth stages resulted in a six-fold variation in deposit So, is one rate or single spray volume applicable throughout the season?

8 Are orchard label rates relevant? With no standard application method, tree spacing, tree structure or coverage pattern required for registration, we have to admit that labels aren t as relevant as they could be Evidence: A U.K. study showed that a fixed rate across orchards provided suitable coverage <50% of the time (2008)

9 Possible impacts Over Spraying Under Spraying > Money in chemicals/time < Efficacy > Unnecessary contamination > Pest resistance over time > Spraying to compensate

10 Crop-Adapted Spraying The CAS model adjusts the amount of pesticide per unit ground area to achieve consistent foliar coverage for canopies of varying shape and density When achieved with sufficient accuracy, pesticide efficacy is maintained

11 Picture three different apple trees

12 The label rate works out to 1 g active / L

13 The applicator uses 1,000 L spray mix / ha

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16 Research & experience suggest a minimum of 85 medium sized droplets per cm 2 and a total area of 10-15% coverage is sufficient for most foliar insecticides / fungicides

17 The method First, the operator has to calibrate the sprayer This should be done for every significantly different block, at the beginning of the season and again around petal fall

18 Here s a common situation: A single orchard with several blocks of variable size, shape, spacing and density

19 Here s how an operator normally sprays (may shut off a nozzle or change speed)

20 Here s my ideal spraying scenario

21 Here s a realistic spraying scenario

22 Turn on/off nozzles & adjust deflectors (if present) to the canopy Use ribbons to extrapolate nozzle centre-points and deflector positions Aim deflectors and nozzles

23 Set fan gear, tractor rpm s and ground speed Attach 3, 25 cm lengths of flagging tape at top, middle and bottom of far side of canopy Do this to 3 plants Calibrate air

24 Partner observes the ribbons as the sprayer passes Air too fast: increase ground speed, reduce rpm s or lower fan gear Air too slow: slow ground speed, raise rpm s or raise fan gear Calibrate air

25 Water sensitive paper Water-sensitive paper: immediate feedback, cheap and easy A min. 85 medium-sized droplets/cm 2 & 10%-15% total area coverage is adequate for most foliar pesticides

26 Determine the rate Orchard parameters, product rates & sprayer settings are entered into an Excel-based calculator The calculator (based on TRV, PACE and other models) proposes the ideal rate & nozzle distribution and saves to a spray record Grower confirms with water-sensitive paper and makes a few tweaks to turn theory into reality

27 Preliminary Trials (2010) According to CAS model, grower applied 80% of typical rates per hectare for one season (4,000 trees) Students scouted weekly and apples were examined upon harvest

28 Insect Pest Orchard 1 CONT CAS Apple Leaf Curing Midge Japanese Beetle Leaf Hopper Oblique Banded Leaf Roller Plum Curculio Rosy Apple Aphid Spring Feeding Caterpillar Tarnished Plant Bug Woolly Apple Aphid Disease Orchard 1 CONT CAS Sooty Blotch Black Rot Powdery Mildew Scab Average weekly counts (17 weeks) Hail destroyed experiment (welcome to field work)

29 Preliminary Trials (2011) Based on CAS, A 2 nd grower applied ~35% less Mancozeb than label rate for one season (no control)

30 Saved $4, that year just for one fungicide

31 Surplus Pesticide

32 Harvest Quality

33 2012 RIP Ontario apple blossoms Gary Gao Ohio State

34 Full Trials (2013-) Full trials included 2 orchards (year 1), 3 orchards (year 2) and 4 orchards (year 3) Sprayer operators used the optimized settings and rates for the CAS (treatment) block, and their typical methods for the control blocks Students scouted each week for weeks and apples were collected at harvest

35 Orchard 1 saved 23% of their spray whole season (2 nd year of trials)

36 Orchard 2 saved 36% of their spray before petal-fall (2 nd year of trials)

37 Orchard 2 saved 29% of their spray after petal-fall (2 nd year of trials)

38 Orchard 3 saved 39% of their spray whole season (1 st year of trials)

39 Data analysis Weekly mean pest count per tree, from 10 trees per condition (apple IPM regime) Skewed data transformed where appropriate GLIMMIX was performed on data with exponential distribution. T-Tests using Tukey-Krameres. Data with low observations were analyzed using Kruskal-Wallis as a non-parametric ANOVA Grouping was carried out using Duncan s multiple range test

40 Data analysis

41 Insect Pest Orchard 1 Orchard 2 CONT CAS CONT CAS Apple Leaf Curing Midge Apple Rust Mite European Red Mite Green Apple Aphid Japanese Beetle Leaf Hopper Mullein Bug Oblique Banded Leaf Roller Oriental Fruit Moth Plum Curculio Rosy Apple Aphid Spring Feeding Caterpillar Tarnished Plant Bug Two Spotted Spider Mite Woolly Apple Aphid Mean weekly counts (15 weeks)

42 Disease Orchard 1 Orchard 2 CONT CAS CONT CAS Bitter Rot Black Rot Powdery Mildew Rust Mean weekly counts (15 weeks)

43 Insect Pest Orchard 1 Orchard 2 Orchard 3 CONT CAS CONT CAS CONT CAS Mullein Bug Tarnished Plant Bug Rosey Apple Aphid Leaf Hopper European Red Mite Two Spotted Spider Mite Spring Feeding Caterpillar Apple Leaf Curing Midge Japanese Beetle Codling Moth Oblique Banded Leaf Roller Plum Curculio Apple Rust Mite Green Apple Aphid Woolly Apple Aphid Mean weekly counts (13 weeks)

44 Disease Orchard 1 Orchard 2 Orchard 3 CONT CAS CONT CAS CONT CAS Apple Scab Black Rot San Jose Scale Mean weekly counts (13 weeks)

45 So, sometimes counts were significantly higher for CAS and sometimes for control However, when the actual counts over the season were graphed, they never came anywhere near spray or economic thresholds

46 Black Rot (2013) Scouted frog-eyed leaf spot (any apple damage captured during apple sampling)

47 Black Rot (2014) Scouted frog-eyed leaf spot (any apple damage captured during apple sampling)

48 Two Spotted Spider Mite (2013) Leaves sampled and nymphs and adults counted under microscope

49 Two Spotted Spider Mite (2014) Leaves sampled and nymphs and adults counted under microscope

50 Leaf Hopper (2013)

51 European Red Mite (2014) Leaves sampled and nymphs and adults counted under microscope

52 Plum Curculio (2014) Scout tapped and looked for fruit damage. PC was active at petal fall

53 Destructive apple sampling (2014)

54 Destructive apple sampling (2013) Occurrences of damage not # damaged fruit

55 Destructive apple sampling (2014) Occurrences of damage not # damaged fruit

56 CAS worked in both high density and semi-dwarf orchards Growers reported that these methods were intuitive and that they would be willing to expand their use of use CAS in fact, I ve struggled to maintain the control blocks! Conclusions

57 Comments Labeled application rates should be structured as a ratio of formulated product to carrier, an ideal coverage standard, and maximum allowances by time or by area Crop-Adapted Spraying (CAS) should become a recognized method for optimizing dosages (like tree-row-volume in the 60 s)

58 Want to try it? I m working with the University of Sask. to develop a free CAS app for Apple (and eventually Android) ETA is summer 2015! Beta testers would be greatly appreciated! jason.deveau@ontario.ca

59 Thanks to: Kristy Grigg-McGuffin (OMAFRA) Behrouz Ehsani (University of Guelph) Hannah Fraser (OMAFRA) Chris Duyvelshoff (Perennia) Hedges Orchards Lingwood Orchards Bell Brothers Orchards Zurbuchen Orchards Jenereaux Orchards Taylor Wallace (OMAFRA summer student) Carly Decker (OMAFRA summer student) Megan Leedham (OMAFRA summer student) Tara Wiedeman (OMAFRA summer student) Horticultural Crops Ontario TeeJet Technologies Inc. Croplife Canada