Pest control efficiency of Pneumatic – Pneumatic+Electrostatic – Conventional spraying systems for vine cultivation

EEA-INTA Agricultural Machinery Section (National Institute of Agricultural and Pasture Farming Technology), Mendoza (Argentine Republic) – Agr. Eng. Raul F. Del Monte

Materials and methods

1. Characteristics of the crop
The efficiency test was conducted at “Estacion
Experimental Agropecuaria Mendoza” (Experimental
Station of Agricultural and Pasture Farming Technology of
Mendoza) of the Istituto Nacional de Tecnologia
Agropecuria (National Institute of Agricultural and Pasture
Farming technology) in the city of Lujan de Cuyo, province
of Mendoza in the Argentine Republic (South America). It
involved 14-year old vines of the Chardonnay variety
grown in the espalier fashion to a height of 1.80 m, with a
2.50 m space between rows and 1.50 m between the
plants.

2. Instruments used for the experiment
a. Berthoud “Air Blast Sprayer” (with droplets sprayed
under pressure and conveyed)
– Assembly system: 3P mounted (universal three-point
hitch)
-Tank capacity: 400 liters
-Type of pump: with three pistons (membranes)
-Number of nozzles: 10
– Nozzle: in ceramic – diameter of hole: 1.1 mm
-Fan: axial flow lift type or with propeller (diam. 800 mm)
with two-way deflector cone
b. Pneumatic system (Mist Blower with conveyed droplets)
and optional Electrostatic charge (Martignani mod. B612
Whirlwind)
– Assembly system: 3P mounted (universal three-point
hitch)
-Tank capacity: 400 liters
– Type of pump: centrifugal
-Number of nozzles: 10
-Fan: centrifugal with double suction action (diam. 600
mm), 2 metering units each with 6 ball valves for wing type nozzles feeding (wing nozzle orifice diameter: 4 mm)

3. Amount of pest control product and application doses
During the test, the product (Mancozeb 80% P.M., a
fungicide of known efficiency against mildew) was applied
in doses of about 2 kg/ha. The corresponding
concentration was calculated according to the required
application volume on the basis of calibration tests.

4. Field test
The pneumatic system was subjected to 6 tests at
different flow rates per unit of cultivation area, ascertaining
the variations in relation to use with or without the
electrostatic charge. The treatment with the “sprayer” was
conducted in the usual way and with the normally used
product flow rates. A blank test was also conducted. The
test area was divided into adjacent comparative lots. The
experimental lot measuring 825 sq m comprised three
crop rows 110 m in length with 6-row side borders and the
drift effect was analyzed up to a distance of 10 m (4
nearby rows).

Table

Treatment   Product flow rate
1(N) Pneumatic 209 l/ha
2(NE) Pneumatic-electrostatic 209 l/ha
3(N) Pneumatic 447.76 l/ha
4(NE) Pneumatic-electrostatic 447.76 l/ha
5(N) Pneumatic 652.17 l/ha
6(NE) Pneumatic-electrostatic 652.17 l/ha
7(A) Conventional Spraying 1160 l/ha
8(T) Blank test without pesticide

5. Coverage assessment
5.1 Visual inspection: collectors, consisting of circular
pieces of polyethylene (diam. 33 mm), were distributed
over the foliage of the plants subjected to each treatment,
where they were applied to the upper and lower faces of
the leaves.
On average, a total of 60 collectors were applied to the
central row of each experimental lot and to 15 of the plants
in the middle sector. Half were applied to the vegetation at
the first level of height (at 0.97 m), while the remainder
were applied 1.57 m from ground level. 15 collectors were

applied at random to the upper faces of the leaves and 15
to the lower faces at each level considered.
Once the treatment had terminated and the droplets had
dried, the collectors were removed and examined visually
so as to assess the entity and density of the impact or
marks, considering two optical fields taken at random on
each collector.

5.2 Chemical assessment: the pesticide deposits were
examined using the universally known acid hydrolysis and
colorimetric method.
A sample of 180 leaves was taken at random from both
sides of the central row of each experimental lot and from
15 plants in the middle sector.
A sample of 30 leaves taken at random from each of the 4
rows near each side border after each treatment so as to
analyze the side drift of each treatment.

6. Operating conditions of the machines
Machine Ground speed
in kph
Operating
pressure (bar)
Attractive force
(HP)
Pneumatic 4 1.5 45
Sprayer 4 17.22 45

7. Weather conditions
Calibration test

Date: 18 Dec. 1995
Time of day: 9:00 hrs
Temperature °C: 26.5
Humidity: 37
Cloudiness: cloudless sky
Wind: slight breeze

Field test

Date: 19 Dec. 1995
Time of day: 7:30 hrs
Temperature °C: 23.8
Humidity: 28
Cloudiness: cloudless sky
Wind: slight breeze

8. Results obtained (see TAB 1 and 2)
NOTE: the results of this report are preliminary and
reserved, in accordance with the conditions established at
the INTA EEA Mendoza conference.

TAB 1

Pest control efficiency of pneumatic and
pneumatic+electrostatic systems for vine cultivation
(Chardonnay variety cultivated with the tall espalier
method)

Treatment
Volume
supplied
(l/ha)
Face Level DP

droplets
sq cm
CVa(%) Cvb(%) p.s.c. e(%)
Initial
depos.
ppm
Dose
dep.
ppm/dose
kg/ha
1(N) 209 L L 80.90 940.65 22.18 16.65 4.84  
217.49 93.751(N) 209 U L 89.52 720.09 37.36 32.08 4.53  
1(N) 209 L U 73.95 774.77 43.87 35.32 3.33  
1(N) 209 U U 85.85 720.10 37.55 31.71 4.17  
2(N.E) 209 L L 73.70 1143.75 22.24 18.10 4.88  
270.79 116.722(N.E) 209 U L 66.70 908.88 22.46 30.78 3.17  
2(N.E) 209 L U 64.59 1184.1 25.27 25.08 3.88  
2(N.E) 209 U U 64.05 906.53 35.03 29.82 2.92  
3(N) 447 L L 76.51 958.43 29.23 15.53 4.41  
214.02 92.253(N) 447 U L 66.02 873.38 26.78 28.34 2.99  
3(N) 447 L U 79.27 836.48 31.04 36.87 4.13  
3(N) 447 U U 75.32 811.65 33.60 37.04 3.62  
4(N.E) 447 L L 56.54 1014.45 17.53 35.49 2.55  
287.25 123.814(N.E) 447 U L 64.17 977.55 17.72 20.81 3.16  
4(N.E) 447 L U 72.00 1112.18 19.24 41.19 4.53  
4(N.E) 447 U U 71.18 892.05 19.63 38.10 3.55  
5(N) 652 L L 71.63 671.96 27.62 43.31 2.71 26.66
91.20 39.315(N) 652 U L 68.33 726.17 27.98 29.72 2.66 4.00
5(N) 652 L U 85.96 703.27 29.61 41.21 4.08 53.33
5(N) 652 U U 78.89 502.34 30.18 35.02 2.45 6.66
6(N.E) 652 L L 72.19 753.75 16.34 27.91 3.08 60.00
110.27 47.536(N.E) 652 U L 82.06 647.20 30.94 35.52 3.42 26.66
6(N.E) 652 L U 84.04 670.10 28.94 34.20 3.72 4.66
6(N.E) 652 U U 69.06 584.49 32.72 37.02 2.12 20.00
7(A) 1160 L L 152.37 366.36 36.39 68.42 6.68 46.00
143.27 61.757(A) 1160 U L 114.96 538.94 37.51 60.50 5.59 46.00
7(A) 1160 L U 163.64 467.91 26.05 67.69 9.84 40.00
7(A) 1160 U U 182.51 361.99 40.18 51.34 9.47 63.00
8(T) ———0.00 0

TAB 2

“Side drift assessment (pesticide deposited in ppm = parts
per million)”

Row (distance in m)
Treatments 1(2.50) 2(5) 3(7.50) 4(10)
1(N) 185.95 75.87 54.84 75.87
2(NE) 262.63 51.75 40.62 43.71
3(N) 186.57 40.62 23.92 61.02
4(NE) 186.57 59.79 52.37 68.45
5(N) 120.39 64.12 46.8 60.4
6(NE) 132.76 53.31 32.59 40.62
7(A) 190.28 94.42 25.25 38.14

Key to tables:

(N) = treatment with pneumatic system (conveyed droplets)
(N.E.) = treatment with pneumatic system and electrostatic system (conveyed droplets with
electrostatic charge)
(A) = treatment with conventional spraying system (sprayed and conveyed droplets)
(T) = blank test, treatment without pesticide
CVa% = coefficient of variability of the diameter of the impacts
CVb% = coefficient of variability of the number of impacts
p.s.c. = percentage of surface covered by the impacts
e% = percentage of runoff, represents the percentage of collectors with drips
L = Lower
U = Upper

Effect of the chemical mixture’s application volume on the efficiency of
the pest control treatment (Vine cultivation with the tall espalier
method, Chardonnay cv.)

Figure 2 Density of the sprayed droplets

Volume of the chemical mixture used (l/ha)

Figure 3 Initial pesticide deposit

Volume of the chemical mixture used (l/ha)

Figure 4 Efficiency ratio

Volume of the chemical mixture used (l/ha)
Deposited/quantity

Figure 5 Sprayed product runoff

Volume of the chemical mixture used (l/ha)