Improving design to minimize costs and risks associated with pest control in strawberries

Final Report for ONE08-087

Project Type: Partnership
Funds awarded in 2008: $9,971.00
Projected End Date: 12/31/2009
Region: Northeast
State: New York
Project Leader:
Andrew Landers
Cornell University
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Project Information

Summary:

Note to the reader: This report contains key tabular data that does not read correctly below. To get an improved version of this data, call the SARE office at 802-656-0471 or send e-mail to nesare@uvm.edu and request final report materials for ONE08-087.

Strawberry growers find it difficult to obtain good disease and insect control when using conventional boom sprayers. Many growers are getting poor coverage of undersides of leaves, lower leaves, and the fruit when the strawberry plant is in full canopy. This results in high levels of disease and insect activity translating to consumer rejection of poor quality fruit.

In the 2008 growing season, two Cornell University researchers and two cooperating strawberry growers conducted trials to investigate the effectiveness of a novel hoop boom system to control insects and diseases.Physical deposition trials were conducted as well as biological effectiveness trials. Trials also compare the hoop system with the traditional horizontal boom. An extension meeting was held in the summer of 2008 and a presentation made at the NY Fruit and Vegetable Expo in 2009.

In an excellent growing season, spray volume was increased as the season progressed using a hoop sprayer. Results, to date, are varied, showing how variety and growth structure can affect deposition, particularly in the bottom of the crop canopy.

Introduction:

Obtaining good coverage in strawberry spraying is a challenge! Certain diseases and insects favor life in the bottom of the canopy and present the sprayer operator with problems regarding penetration and deposition within the canopy. traditionally growers use high pressure to penetrate the canopy but nowadays off-target drift is a major problem and can contaminate other crops as well as upset the neighbors.

In the past, researchers in Norway, Bjugstad N. and Sonsteby A., have conducted trials using various prototype booms with different application rates. we developed a trial in which we adjusted the number and angle of nozzles as the season progresses to match canopy volume. Our project also looked at biological effectiveness as well as physical penetration, deposition and coverage of the plants under New York growing conditions.

In the 2008 growing season, two growers, John Hand of Greenwich, NY and Dale Riggs of Stephentown, NY kindly agreed to cooperate with Andrew Landers and Laura McDermott on this project.

Project Objectives:

1.To study deposition within the strawberry canopy using a conventional boom sprayer with standard hydraulic nozzles and compare to:
2. deposition from a hoop sprayer which will direct the spray into the canopy
3.Compare 3 nozzle configuration with a 5 nozzle configuration to match the growing canopy as the season progresses
4.To match application volume with the growing canopy
5.Make recommendations on spraying techniques for strawberry growers

Cooperators

Click linked name(s) to expand
  • John Hand
  • Laura McDermott
  • Marvin Pritts

Research

Materials and methods:

We manufactured two hoop booms to fit to the grower’s sprayers using off-the-shelf sprayer components such as nozzle tips, nozzle bodies and strainers mounted onto a fabricated hoop boom.

In early season, May 2008, we fitted three nozzles to the prototype. As the canopy grew we will fitted five nozzles. We tested three different nozzle types (treatments) to ascertain the most biologically efficient nozzle as well as study the physical effects. We used hollow cone nozzles, favored by many farmers and compared them with flat fan nozzles. The grower also sprayed a portion of the plot with his/her conventional boom sprayer for comparison to the hoop boom. The farmers current sprayers are hydraulic folding booms fitted with hollow cone nozzles at 18” spacing. Sprayer A had a piston pump that operates at 150 psi and is calibrated to spray 68 gallons/acre at a 5 mph speed. Sprayer B was a small mounted sprayer, operating at 84 gallons/acre at 2mph and at 40 psi.

Deposition on the crop was measured by adding Pyranine fluorescent tracer into the sprayer tank to make a 0.05% solution. Real concentration of tracer in the tank before and after spraying was measured taking samples directly from the tank.

Quality of applications was measured by picking leaves from the top, middle and bottom part of the canopy. Three leaves from each area were placed into plastic bags and sealed.
10 plants per treatment (nozzle type) were selected, with five replicates.
All leaf and fruit samples were kept cool and transported to Geneva.

The extraction of deposited tracer on the leaves was determined by washing leaves in the bags by adding an exact quantity of washing liquid. Plastic bags containing leaves were well shaken and leaves remained in contact with the washing liquid for 30 minutes.A sample of this liquid was collected and placed in a crystal tube. Concentration of tracer was determined by using a BioRad fluorimeter.

Surface area was obtained for every variety and at the two crop stages when the trials were conducted, early/mid canopy and full canopy. Deposition was expressed in terms of deposition by leaf surface (micrograms/cm2). Leaf surface was measured using a planimeter.

Biological efficacy
All treatments were compared in terms of biological efficacy (by measuring the level of control of insects/disease) and in terms of quality of applications by determining aspects as coverage on leaves, uniformity of distribution, and capacity for penetration.

For the biological efficacy control, samples of fruits and leaves from different parts of the canopy were inspected at the end of the season, levels of insect and disease infestation after treatments were measured by my colleagues.

Data collection was the responsibility of Laura McDermott, cooperator from the Cornell Berry program and the cooperating farmers. Data analysis was the responsibility of the Principal investigator, Andrew Landers, and his staff.

Research results and discussion:

Table 1 Strawberries 2008 Final Results
Farm D May 2008 Average Fluorescence per Area

Location of Leaves within the Plant
Fluorescence/Area (square cm)
Boom Hoop
Top 8.753 4.544
Middle 2.364 2.496
Bottom 0.693 1.14

Farm J May 2008 Average Fluorescence per Area
Location of Leaves within the PlantFluorescence/Area (square cm)
Boom Hoop
Top 12.497 6.557
Middle 4.113 3.051
Bottom 1.25 1.408

Farm D June 5 2008 Average Fluorescence per Area

Location of Leaves within the Plant Fluorescence/Area (square cm)
Boom Hoop
Top 17.109 14.621
Middle 3.814 7.739
Bottom 1.867 4.784

Farm D June 6 2008 Average Fluorescence per Area
Location of Leaves within the Plant
Fluorescence/Area (square cm)
Boom Hoop
Top 5.03 3.49
Middle 0.697 1.388
Bottom 0.352 0.406

Table 1 clearly shows that deposition was greatest in the bottom of the canopy when the hoop system was used.

Disease ratings:-
7 random leaves within each of 5 replications were evaluated and ranked 1-5 for degree of infection where 1=no infection and 5=entire surface infected.

Fruit observations:-
Random fruit for each of 4 replications were evaluated for degree of disease infection and/or insect damage, where 1= no damage on fruit and 5= fruit heavily infected and/or damaged.

Table 2. Presence of foliar diseases of strawberries resulting from the use of different sprayer designs.

Rating totals for each treatment on:

Modified boom (hoop)
June 17, 2008 June 27, 2008 July 8, 2008
Farm A Farm B Farm A Farm B Farm A Farm B
7.71 8.86 6.86 8.00 6.43 8.00

Traditional boom
June 17, 2008 June 27, 2008 July 8, 2008
Farm A Farm B Farm A Farm B Farm A Farm B
8.71 8.86 7.86 7.43 10.00 8.71

Control (no spray)
June 17, 2008 June 27, 2008 July 8, 2008
Farm A Farm B Farm A Farm B Farm A Farm B
8.43 9.43 7.14 7.43 7.14 9.00

Presence/absence of disease ranking system, 1=no disease, 5=totally covered with disease
(CRD, 5 replications and 3 treatments. 7 observations/rep)

Table 3. Presence of disease or insect damage on fruit resulting from the use of different sprayer designs

Rating totals for each treatment on:

Modified boom (hoop)
June 17, June 27, July 8,
Farm A Farm B Farm A Farm B Farm A Farm B
6.28 6.36 4.52 5.28 6.20 5.84

Traditional boom
Farm A Farm B Farm A Farm B Farm A Farm B
6.40 6.80 5.36 5.88 6.60 6.84

Control (no spray)
Farm A Farm B Farm A Farm B Farm A Farm B
6.08 7.60 5.04 7.24 5.64 7.32

Presence/absence of disease or insect damage, 1=no damage, 5=complete damage.
(CRD, 3 treatments, 4 reps, 25 observations /rep)
Conclusions
Data does not support significant statistical differences between treatments, however…
Clear and consistent trends are apparent.
For 4 of the 6 comparisons, the use of the modified boom (hoop) appears to have an advantage over the traditional boom in the control of foliar disease.
For all 6 comparisons, the use of the modified boom (hoop) appears to result in a lower incidence of disease infection and/or insect damage on the fruit than does the use of the traditional boom.

The objectives were successfully met and all equipment performed well.

Milestones

We accomplished all we set out to do, we evaluated the two hoop systems on growers farms, on time, and with interesting results. All milestones were met, in a timely fashion with one exception. The weather was exceptionally good for strawberries so this year early and mid canopy development occurred extremely rapidly.

Research conclusions:

At the time of writing, the outcomes are that we have shown 100 growers in an extension meeting and at a conference that the hoop boom warrants further investigation on their own farms. We have certainly drawn their attention to the fact that, as sprayer operators, they need to fully understand the need for penetration without drift, for correct volumes per acre as the canopy develops over the season and for good timing.

Spraying has for too long been neglected in small fruit growing and this project has provided a most valuable entry into this important subject.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Extension meeting
A very successful extension meeting was held for growers on the 2nd July at John Hand, Hand Melon Farm, Greenwich, NY on the 2nd July. Approx 20 people attended. Our host, John Hand, drove the tractor and regular boom sprayer with clean water in the tank, this was followed using the hoop system. Growers were able to see the techniques and see penetration in a mature crop of strawberries, prior to market. A great discussion followed and growers, some who had travelled a good distance, appeared extremely interested in the project.

Conference meeting
Designing a better sprayer for pesticide application in strawberries. Presented at The 2009 Empire State Fruit and Vegetable Expo. Oncenter Convention Center. February 12th, Syracuse, NY
Paper available from the conference organisers or from the authors

Publication
Landers, A.J. and McDermott, L. (2009) Designing a better sprayer for pesticide application in strawberries. Proc. The 2009 Empire State Fruit and Vegetable Expo. February 11-12, Syracuse, NY. pp 172-173, Ithaca: Cornell Cooperative Extension

Project Outcomes

Project outcomes:

Farmer Adoption

It is too early to say if others have adopted this technology, but it can be easily made on the farm.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

It would be wonderful for researchers (but not necessarily so for the strawberry growers) if this trial could be conducted again in a high disease year to enable a very thorough understanding of the hoop and volume systems.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.