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

Inta Mendoza Argentina

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 a 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 sqm 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

Trattamento 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 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
(lt/ha)
Face Level DP N.
droplets  sq cm
CVA(%) Cvb(%) p.s.c. e(%) Initial deposit
ppm
Dose deposit ppm/dose Kg/ha
1(N) 209 I I 80.90 940.65 22.18 16.65 4.84   217.49 93.75
1(N) 209 S I 89.52 720.09 37.36 32.08 4.53  
1(N) 209 I S 73.95 774.77 43.87 35.32 3.33  
1(N) 209 S S 85.85 720.10 37.55 31.71 4.17  
2(N.E) 209 I I 73.70 1143.75 22.24 18.10 4.88   270.79 116.72
2(N.E) 209 S I 66.70 908.88 22.46 30.78 3.17  
2(N.E) 209 I S 64.59 1184.1 25.27 25.08 3.88  
2(N.E) 209 S S 64.05 906.53 35.03 29.82 2.92  
3(N) 447 I I 76.51 958.43 29.23 15.53 4.41   214.02 92.25
3(N) 447 S I 66.02 873.38 26.78 28.34 2.99  
3(N) 447 I S 79.27 836.48 31.04 36.87 4.13  
3(N) 447 S S 75.32 811.65 33.60 37.04 3.62  
4(N.E) 447 I I 56.54 1014.45 17.53 35.49 2.55   287.25 123.81
4(N.E) 447 S I 64.17 977.55 17.72 20.81 3.16  
4(N.E) 447 I S 72.00 1112.18 19.24 41.19 4.53  
4(N.E) 447 S S 71.18 892.05 19.63 38.10 3.55  
5(N) 652 I I 71.63 671.96 27.62 43.31 2.71 26.66 91.20 39.31
5(N) 652 S I 68.33 726.17 27.98 29.72 2.66 4.00
5(N) 652 I S 85.96 703.27 29.61 41.21 4.08 53.33
5(N) 652 S S 78.89 502.34 30.18 35.02 2.45 6.66
6(N.E) 652 I I 72.19 753.75 16.34 27.91 3.08 60.00 110.27 47.53
6(N.E) 652 S I 82.06 647.20 30.94 35.52 3.42 26.66
6(N.E) 652 I S 84.04 670.10 28.94 34.20 3.72 4.66
6(N.E) 652 S S 69.06 584.49 32.72 37.02 2.12 20.00
7(N) 1160 I I 152.37 366.36 36.39 68.42 6.68 46.00 143.27 61.75
7(N) 1160 S I 114.96 538.94 37.51 60.50 5.59 46.00
7(N) 1160 I S 163.64 467.91 26.05 67.69 9.84 40.00
7(N) 1160 S S 182.51 361.99 40.18 51.34 9.47 63.00
8(N) 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.)