To know more visit: Electrostatic Mist Blower vs. Air Blast Sprayer

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1. Electrostatic Mist Blower Vs. Air Blast Sprayer
2. Electrostatic Mist Blower demo on citrus crops with dye product.

A. Cesari, R. Davi*, F. Castagnoli**, P. Flori

Department for the Protection and Development of Agri-foodstuffs Plant Pathology Section – University of Bologna (Italy)

You can download the .pdf file clicking on the link: Low Volume” Phytoiatric Applications With Electrostatic Distribution Systems

Foreword and scopes

Use of “electrostatic” and “electrodynamic” equipment in the “low volume” pesticide distribution systems employed for plant protection is arousing considerable interest owing to the improvements it can achieve in the formation of an even coating of the product it deposits over the plants in question.

While the polarity induced in the finely micronized drops reduces wastage due to drift, it also prevents the drops from aggregating during the dynamic phase of the conveying action and from overlapping each other when they strike the surfaces of the plants.

This produces significant effects on the degree of protection achieved and reductes the amount of product that goes to waste (Marchant and Green, 1982; Spilman, 1984).

Interesting results were observed when these systems were used for treatments on herbaceous crops such as wheat, barley, cotton, etc. (Lav. 1982; Arnold et al., 1984) even though in certain cases, penetration of the pesticide mixture into the vegetation was limited by the thick foliage (Cayley et al., 1985).

On the other hand, there are few indications concerning applications on tree crops, especially as the progressive establishment of the “low volume” method (Cesari et al., 1984) would appear to represent an interesting option (Inculet et al., 1981).

To add to the information concerning the real possibilities offered by electrostatic systems, certain trials were conducted during the 1984-85 two-year period.

The intention was to assess the efficacy of a “low volume” pneumatic-electrostatic mist blower used for treatment against apple scab by applying progressively lower doses of fungicide while quantifying the amount of product that actually deposited on the treated surfaces.

Materials and methods

The tests were conducted in the province of Ravenna in an 8-year old apple orchard covering some 600 m2 (cv. “Starkrimson”) cultivated with the fan-tree method (2.10 x 4.10 m) and with foliage (L.A.I.) measuring an average 8 m in length. The trees were 350 cm in height and the foliage 100 cm thick.

The tested equipment was a pneumatic system (MARTIGNANI-KWH-B612) operating at a “low volume” (100 l/ha in 1984; 120 l/ha in 1985), which had been fitted with an electrostatic device able to generate a 15000 Volt potential difference with 150 μ voltage.

The phytoiatric efficiency was assessed on the basis of the degree of protection against Venturia inaequalis provided by the two systems, pneumatic and pneumaticelectrostatic, which were operated one at a time. The machines advanced at a speed of 6 kph during the treatment.

The fungicide products used were bitertanol + mancozeb in 1984 and triforine + dithianon in 1985, applied in progressively decreasing doses (-25% in 1984; -20% and – 40% in 1985) compared to the “standard” dose used at a “normal volume” of 1500 l/ha (tab. N° 1 and N° 2).

At both times, the treatments against apple scab were carried out to combat infections which had occurred during the period between blooming and growth of the fruit (tab. N° 1 and N° 2).

Assessments made after all the infections had been dealt with involved the fruit and leaves at three different foliage heights (h1 50-150 cm; h2 150-250 cm; h3 250-350 cm).

During 1984, assessments were also made in order to achieve a comparative evaluation of the amount of plant protection product (bitertanol) deposited on the apple tree leaves after one single application of a “standard” dose. Samples were then subjected to gas-chromatographic analysis after extraction of the active principle.

Analysis of the results

Working in conditions that were very favourable for the development of v. inaequalis infections and using a mixture of fungicides possessing a high degree of biological activity, especially in relation to the curative function, a good degree of leaf and fruit protection was observed for both the distribution systems used, as shown by the results obtained during the course of 1984 (tab. N° 1).

However, the tendency of the pneumatic-electrostatic system to provide a better protection for the leaves than the fruit was observed in these conditions.

25% dose reductions did not appear to sensibly influence the degree of leaf protection provided by the two systems. On the other hand however, and unlike the results observed for the “standard” dose applications, it should be emphasized how the pneumatic-electrostatic system tended to achieve a higher degree of action on the fruit.

In relation to the protection provided by the two systems at the various different foliage heights and to the different doses used, progressively increasing values of apple scab infection were evident in both the leaves and fruit as the height of the foliage progressed from 50 cm to 350 cm.

The assessments made in 1985, when the tests were conducted in the presence of

a more serious infection than the previous year owing to the considerable quantity of v. inaequalis inoculum and using a mixture of fungicides possessing a high curative and preventive action (trifoline + dithianon), highlighted more marked differences in the action of the two distribution systems than those observed in 1984, also in relation to dosage reduction and the type of plant organ being protected.

More specifically, when the tests were conducted with a “standard” dose, we noted that the pneumatic-electrostatic system always provided a superior degree of action, although to no significant extent, than the pneumatic system in relation to both the foliage and fruit.

The electrostatic system’s greater degree of action was particularly evident with decreasing doses of product when it came to protecting the fruit, where applications with this system using doses reduced by 20% did not diminish the degree of action in any significant way, unlike the pneumatic system. In actual fact, the applications made with the pneumatic-electrostatic distribution system with doses reduced by 20% achieved similar results to those obtained with the pneumatic system and “standard” doses of product.

A further reduction to the dose (40%) led to a significant decrease in the degree of protection for both the systems as compared to applications with “standard” doses of product. In such operating conditions, the pneumatic system also presented significantly reduced levels of action in relation to applications made with the pneumatic-electrostatic system and 20% dosage reductions.

TAB. N° 1 – Distribution systems, product doses and results of the protection treatment against apple scab – year 1984 -

TAB. N° 2 – Distribution systems, product doses and results of the protection treatment against apple scab – year 1985 -

When the dose was reduced by 40%, a significant decrease in the degree of foliage protection for both the systems was only observed in comparison with the pneumaticelectrostatic system and “standard” doses.

Further analysis of the results concerning the trend of the % increases in the degree of action provided by the electrostatic system as compared to the pneumatic one in relation to dosage variation (Fig. N° 1) showed that while, speaking of the fruit, that increase grew as the doses decreased, there were no appreciable variations on the foliage, thus confirming that the electrostatic system is highly efficient for fruit protection.

With regard to the protection achieved at the different foliage heights, the results of the previous year were confirmed again, thus the degree of action provided by both the systems decreases as the plants become taller.

The analysis showed that there was a greater amount of active principle deposited on the leaves (Fig. N° 2) in the plots treated by the pneumatic-electrostatic system and this confirmed the results of the biological action.

We also noted that when the product was applied with the electrostatic system, the presence of wind (0.3 m/sec.) did not influence the formation of the deposit in either of the rows directly subjected to the treatment, on which the weighted values were more or less identical.

The results of the applications made with the pneumatic system were extremely different, as a greater quantity of product was applied to the downwind row, thus highlighting the problem of reducing drift.

The results obtained from the two-year experimentation allow the following considerations to be made:

- Applied to the “low volume” pneumatic system, the electrostatic device sensibly improved

the phytoiatric efficiency of the treatment against apple scab.

FIG. N° 1 – Variation of the ratios pertaining to the % increases of the degree of foliage and fruit protection provided by the electrostatic system as compared to the pneumatic one in relation to the reduction in the dose of product applied per unit of area.

	fruit
	% increases in the degree of protection
	foliage
% dose reduction

FIG. N° 2 – Foliage coverage of bitertanol after an application with the examined distribution systems

Left-hand rows		Right-hand rows
wind direction	Line of advancement		pneumatic-electrostatic system
(0.30 m/sec)	of vehicle		pneumatic system

- The more evident positive effects of the applications made with these systems were achieved in relation to fruit protection, also when reduced amounts of product were used.

Compared to the pneumatic system used with the “standard” dose, the degree of protection did not diminish when 20% less product was used even when serious infections by the pathogen were treated.

- Since it created less drift, the pneumatic-electrostatic system also proved to be superior when it came to plant coverage, as less product was dispersed in the environment and wasted.

- However, the pneumatic-electrostatic system failed to achieve any substantial improvements in the protection of the higher parts of the foliage, where drift phenomena were more accentuated.

This was evidently due to the attenuation to which the electrostatic charges were subjected owing to the longer distance the droplets were forced to travel in order to reach the tops of the trees.

In conclusion, the electrostatic system proved to be valid owing to the advantageous way it was able to distribute plant protection products over tree crops by means of equipment operating in the “low volume” mode.

More specifically, this system helps to get the most out of “low volume” applications since it improves the degree of coverage over the plants, particularly the fruit, reduces the amount of product that goes to waste through drifting or losses on the soil and thus requires less of the plant protection product itself.

However, use of the electrostatic system generally depends on the chemio-physical and biological characteristics of the pesticide employed, the type of pathogen and the seriousness of the infection it causes as well as the shape and size of the foliage treated.

Summary

Efficacy of “Low Volume” Sprays for Apple Scab Control With The Electrostatic-Pneumatic Spray System.

The results obtained during a two-year trial period clearly demonstrated the superiority of an electrostatic-pneumatic spray system as compared to a simple pneumatic system for treating apple scab with fungicides, especially as regards fruit protection.

Lower fungicide doses (up to 20% less) could be delivered by this system since less product was wasted due to drift while a higher amount was deposited on the surface of the fruit.

However, the pneumatic-electrostatic system did not appear to substantially improve the degree to which the taller parts of the foliage were protected.

Bibliography

Arnold A.J. et al. (1984). Biological effectiveness of electrostatically charged rotary atomisers. I. Trials on field beans and barley. 1981. Annals of applied biology, 105, 353-359.

Cayley G.R. et al. (1985). Review of the relationship between chemical deposit achieved with electrostatically charged rotary atomisers and their biological effects. British Crop Protection Conference; Symposium on application and biology, 28, 87-96.

Cesari et al. (1984). Confronto fra sistemi di distribuzione e dosaggi diversi nella difesa dei fruittiferi dai fitofagi (acari e cemiostoma). Atti Giornate Fitopatologiche, 2, 243-252.

Inculet et al. (1981). Deposition studies with a novel form of electrostatic crop sprayer.

Fourth international conference on electrostatics to be held in the Hague, the Netherlands, 6-8 May 1981.

Law S.E. (1982). Spatial distribution of electrostatically deposited sprays on living plants.

Jour. of Econ. Entom. 75, 524-544.

Marchant J.A., Green R. (1982). An electrostatic charging system for hydraulic spray nozzles. Journal of Agricultural Engineering Research, 27, 309-319.

Spillman J.J. (1984). Spray impaction, retention and adhesion: an introduction characteristics. Pestic. science, 15, 97-106.

——————-

* E.R.S.O. scholarship holder working on research financed by the Regione Emilia-Romagna authority – Department for Productive Activities, Agriculture and Nutrition. ** E.S.A.V.E. scholarship holder.

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The Electrostatic Martignani Whirlwind B612 shows superior coverage.

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Energy Conveyance Service and Telecommunications,
Supply Centre of the Conveyance
Network – Travaux du Mans

128, Avenue Felix Geneslay,
72100 Le Mans – FRANCE
Tel. 43.84.72.33 E.D.F.
R.C. Paris B 552 081 317

=============================================

Person in charge:
Mr MAIRESSE

To the
BRICAUD ESTATE Techno agricultural
570, Rue du Maréchal Foch 44370
V A R A D E S  -  FRANCE
Attn.: Mr. BRICAUD

=============================================

Le Mans, July 6th, 1989

Re: Electrostatic Mist-Blowing

Dear Sirs,

We wish to thank you for making available the equipment for spraying orchards with the electrostatic mist-blowing system.
A range of tests were carried out on our request at the E.D.F. High Voltage laboratory in Renadières (Moret sur Loing) with a view to answering the following questions:

Can the electric field caused by a 400 kV line over the fruit trees affect the efficiency of the electrostatic mist-blower? Is there any danger involved if the conductor cables are directly wetted by the mist-blower?

We would like to mention that the questions derive from the operating principle of the electrostatic mist-blower: charging the chemical droplets with a negative electrical charge, so that when they reach the trees, having an opposite polarity (+) they are attracted by the two faces of the leaves.

Some hundred tests were carried out, reproducing the real field conditions:

electrical field on the ground below a 400 kV line perpendicularly to its lowest point = 5.4 kV/m (1)
at 1.5 m from the ground below a conductor placed 8.5 m from the ground (minimum height and maximum operating temperature of the 400 kV lines).

Horizontal and vertical slot rain gauge; to measure the volumes of chemicals caught during a 10 minutes’ treatment. The rain gauge was connected to the ground and placed at a height of 3 to 5 m over the mist-blower.

At comparable weather conditions (in particular wind speed and direction) the tests showed that:
the electrostatic system is efficient (the quantity of product caught is 30 to 40% higher than with non-electrostatic systems)
the electric field of a 400 kV line does not modify the efficiency of the mist-blower.

As concerns the safety in use of electrostatic mist blowers below 400 kV lines, more tests were carried out and the most unfavourable conditions were chosen (electric field 6.8 kV/m at 1.5 m from the ground, perpendicularly to the lowest point of the conductor instead of 5.4 kV /m below the lines; chemical product with the highest conductivity, maximum spraying rate by the blower, straight wetting of the conductor, mist blower connected to the ground).
The very low current levels through the blower were always below the values that might cause pathological effects as listed in the C.E.I. 479 publication.

(1) Max. value affecting a small surface below the line (500 sq.m. for a length of 500 m).
(2) C.E.I. = International Electro technical Committee

As a conclusion, the presence of a 400 kV line over the orchards does not affect the efficiency of the treatments with electrostatic mist blowers and poses no danger.

Thanking you again for your cooperation, we are

Yours sincerely,

The Le Mans Base Chief
J. P. MAIRESSE

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You can download the .pdf file clicking on the link:

Efficiency Comparison Table

Planting distance: 3×5 m – Average ground speed during the treatments: 3.5 kph Martignani-KWH Electrostatic Mist Blower used: Mod. Whirlwind B612  1500 l TURBO 2 with ELECTROSTATIC

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

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
N°
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)

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<< FIELD TEST >>
PROJET
FINAL REPORT
April 2002

I.C.E. – Délégation Commerciale d’Italie – Tunis
Tél : 00216 / 71940.522 / 71940451 / 71940.458 – Fax : 00216 / 71940.464 / 71940.460
e-mail : tunisi.tunisi@ice.it – site web tunis : http//www.ice.it/estero2/tunisi/default2.htm

SEMINAR SCHEDULE HOTEL HILTON – Tuesday 16 April 2002

9 a.m.: Participants welcomed and registered.

9.30 a.m.: Opening speech by Mr. Alberto CATARCI, Director of the Foreign Trade Institute.
9.45 a.m.: Welcoming speech by the Trade Councillor of the Italian Embassy in Tunis, Mr. Marco
VILLANI.
10 a.m.: Presentation of the project by Mrs. Mirella FINETTI of the External Centre of the
Chambers of Commerce of the Regione Emilia Romagna department.

10.15 a.m.: Main actions of the project by Mr. Elies HAMZA of I.N.A.T.
10.30 a.m.: Mechanization in tree culture by Mr. M. BEN MIMOUN of I.N.A.T.
11 a.m.: First-hand knowledge and affirmations of a producer, Mr. M. MECHICHI.
11.30 a.m.: Coffee break.
11.45 a.m.: Orchard cultivation by Mr. Elies HAMZA of I.N.A.T.
12.15 p.m.: Mechanization in olive growing practices by Mr. H. BEN TAHAR of the Olive
growing Institute.
12.45 p.m.: Mechanization of the oases by Mr. BCHINI of INRAT.
1.15 p.m.: Debate

THE ACTION OF ELECTROSTATIC MIST-BLOWING

I / Introduction

In the majority of pesticide applications, product distribution and its uniformity of coverage are bound to the efficiency of the treatment operation. Thus different methods have been used to evaluate the degree of dusting and the amount of product deposited.
The equipment used for tree culture includes: the “sprinkler”, the “spraying bar”, the “atomizer” and the “mist blower”. The choice of one of these methods depends on certain parameters: the cost of the investment in materials, the structure and size of the farm and the efficacy of the material itself.

At the present time, the most efficient technique is pneumatic mist blowing
whereby a flow of liquid at low speed and low pressure is brought into contact
with a high-speed air flow (>80 m/s). Contact of the air with the liquid causes
the mixture to micronize into droplets. The droplets will become more
homgeneous and their diameter smaller as the air speed becomes faster and
the amount of liquid that passes becomes less. Fine and homogeneous
spraying allows the area covered to be sensibly increased while reducing the
volume of mixture used (from 100 to 200 l/ha) in relation to pressurized
atomizing of the liquid which uses consistent volumes (from 500 to 1500
l/ha).
Pneumatic mist blowing can be equipped with a device for electrostatically
charging the droplets. The droplets are attracted towards the vegetation by
the electrostatic fields that form between the plants, which are optimum
conductors (sap, mineral salts, humidity, etc.) and chemical vapour, carriers
of an electrostatic charge.
Our tests were conducted to compare the action of electrostatic mist blowing
with that of a classic pneumatic mist blowing process, beginning with the
degree to which the droplets of mixture cover the leaves and using the image
analysis method.

II / Materials and methods

Two pneumatic mist blowers, a classic mist blower and an electrostatic mist
blower were tested in an apple tree orchard (fig. 1).
The test conditions were: wind speed 2 m/s, 40% relative humidity and an
ambient temperature of 24°.
The tests were conducted using pieces of water-sensitive paper (2.54 x 2.54
sq.cm) which turned blue when struck by the water droplets, thus giving rise
to the relative coverage rate. The pieces of paper were affixed to the two Tunisia – field test project – final report
sides of the leaves and were then pointed towards the north, south, east,
west and center of the trees.
After the implements had passed and the pieces of water-sensitive paper had
been wetted, they were collected and digitized by means of an A4 colour
scanner whose resolution setting was 600 dpi.
The images were digitized in the red channel at 256 levels of grey. Each pixel
was a square measuring 42 m m each side. The smallest droplet mark
identified measured 50 m m which, using a distribution factor of 2,
corresponded to droplets 25 m m in diameter.

Fig. 1 – Electrostatic mist blowing
Double-suction centrifugal fan
1.5 bar l/h calibrating device with
regulating valves to adapt the jet
to the shape of the tree
Electrostatic diffuser unit

Tunisia – field test project – final report

Fig. 2 : Positions of the pieces of water-sensitive paper on the trees Fig. 2 : Positions of the pieces of water-sensitive paper on the trees
III / Results

A four square centimeter area of digitized image was treated. It was filtered
to increase the contrast between the droplets and the background. Selection
was limited to a level of grey so as to obtain an image where the pixels were
black or white, depending on whether their level of grey was above or below
the established threshold. The droplets of the original image were thus
isolated on a white background. Using this image, the “Image Tool” logic was
able to identify objects or droplet marks.

The coverage rate results (Fig. 3) show that electrostatic mist blowing
obtained higher coverage rates than the classic pneumatic mist blowing in all
cases. An analysis of the variant of the two treatments showed that
electrostatic mist blowing was more homogeneous than classic pneumatic
mist blowing.

Tunisia – field test project – final report

Coverage rate %

An analysis of the pieces of water-sensitive paper positioned on the trees
and on the ground showed that unlike the classic mist blowing process, the
pieces of paper failed to turn blue in the case of electrostatic mist blowing.
This confirmed electrostatic mist blowing’s total absence of loss through
drifting and flowing.

Fig. 3 : Histogram of the rate of coverage obtained from the two mist blowing
processes
0
5
10
15
20
25
30
1 2 3 totale
Mist blowing Electrostatic
Tunisia – field test project – final report

ACQUISITION OF THE IMAGE FOLDER

The pieces of water-sensitive paper are digitized by means of a scanner.
The “images” folders are processed by an “Image Tool” image analysing software.
The image is filtered to increase the contrast between the drops and background.
The threshold of the image is established at a fixed level of grey so as to binarize it.
The drop marks are identified and the elongation, area and coverage rate parameters calculated.

Related posts:

1. Electrostatic Mist-Blowing

Up stream , the woods extend up to 900m above sea level on the Pizzorne sandstone rock. Upstream is the vast plain of Capannori.

We tread the Tuscan land and find ourselves at number 7 di Valgiano street in Valgiano, in the district of Lucca.

Dr. Petrilli tells us that the first meeting with Martignani company was favoured in 1997 from the purchase of a used Martignani-KWH Mist Blower of the Whirlwind B612 600 l trailer version.

Since then, other meetings have taken place leading the Valgiano estate to equip itself, in the following years, with both a trailer and 3P Mounted model .

The Valgiano estate is an organic farm which adopts biodynamic agricultural systems.

Its vineyards lie on a terrace of pebbles and clay in Alberese. The Sangiovese is preferably cultivated along the crest of Alberese due to the soil which allows it to maintain aromaticity as well as a good structure.On the clayey surface Merlot is cultivated due to its ability to maintain delicacy and elegance even on clay; and, on the sandy pebbles of sandstone, only Syrah can give structure as well as fragrance.

All the treatments are carried out on alternate rows (every two rows) and state volumes/ha, during the season, from 100 to 200 l/ha for both fungicide and insecticide treatments.

The entire vineyard surface is covered in about 2 days utilizing both the Mist Blowers, considering that the vineyards are divided into several distant plots and in some cases with considerable slopes.

The Martignani Mist Blowers lend themselves very well to the treatments of the plant as it is indispensable to offer an excellent coverage of the vegetation even in the periods of highest growth in order to guarantee the maximum efficiency of the operation.

Dr. Petrilli tells us lastly that amongst the numerous advantages noted in the last 10 years of use, besides minimal maintenance and assistance, it was possible to ascertain great affordability even during years of adverse weather conditions, thus arriving at harvest with a healthy product, without disease and residual chemicals.

We, ourselves add the fact that we have found traces of the Valgiano Estate in several virtual places, and not only on paper.

• This Book Will Change Your Life by Benrik (Paperback – Oct 28, 2003)
• The Global Encyclopedia of Wine, Updated Edition (includes CD-ROM) by Peter Forrestal (Hardcover – Oct 15, 2001)
• Anthony Dias Blue’s Pocket Guide to Wine 2006 (Anthony Dias Blue’s Guides) by Anthony Dias Blue (Paperback – Sep 20, 2005)
• Central Italy: The Collected Traveler: Tuscany and Umbria by Barrie Kerper (Paperback – Sep 26, 2000)
• Zingerman’s Guide to Good Eating: How to Choose the Best Bread, Cheeses, Olive Oil, Pasta, Chocolate, and Much More by Ari Weinzweig (Hardcover – Nov 14, 2003)
• Wine Encyclopedia by Catherine Fallis, James Lawther, Maureen Ashley, and Patrick Farrell (Paperback – Oct 2002)

As for the Internet, only the search engine Googlecertifies and lists the presence of 10,400 pages of its index which deal with the Valgiano estate.

It gives us pleasure to end this brief article with the Valgiano estate’s 2003 chart, taken from an online site ,which is a final explanatory summary.

Vine: Sangiovese 60%, Syrah 20%, Merlot 20%
Denomination: Tenuta di Valgiano
Colour: red
Fragrance: gives an elegant and fine aroma to the nose. Fragrant aromas of mature fruit, hints of spice and minerals and an Intense and persistent bouquet.

Taste: a catchy taste on the palatecombined with a pleasant fruity sweetness. The structure develops with a deep texture of soft, mature tannins which ensure the duration of a delicious and pleasurable after taste.

No related posts.

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
N°
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)

Related posts:

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

The Randi Farms is situated in the municipality of Fusignano (Ravenna) and is managed by Dr. Massimo Randi with the collaboration of his brother Denis and father Luigi.

The vocation of the farm is decidedly viticultural, being about 25 hectares of vineyards, although other cultivation such as peach trees, wheat and beetrootin smaller quantities are not left out.

The technical approach of “Martignani” Electrostatic-Mist Blowers was integrated some time ago following a professional conference between Dr. Randi and Dr. Bellettini, the latter presently being an agricultural technician (Agronomist) and manager of the Martignani srl Italian counting house.

The contactwas concretised in the spring of 2005 with the purchase of the Mod. Whirlwind B-612 TURBO 2 Pneumatic Mist Bower with Electrostatic charged droplets.

At first the insecticide treatments were carried out by Luigi. It was then Dr. Massimo who dealt with thephytosanitary management of the family vineyards, personally carrying out the defence operations on board a tractor..

We have now come to the fourth season using the Martignani Mist Blower and Dr. Massimo tells us about the convenience of having invested in this equipment and how we have reached the optimization of the productive processes.

At the speed of 8,3 Km/h with a volume/ha of 200 litres, 7,5 ha are treatedin the morning and7,5 ha in the afternoon while the remaining hectares are completed the following day.

Previously, with a conventional atomizer (or Air Blast Sprayer) distributing 600 litres/ha, several refuelling and a total of 4-5 days of time were required.

Only some treatments , such as those against moth infestations of the grape-vines, are carried out at a higher volume (400 l/ha), while the remaining, and larger part, of the field is treated at 200 l/ha.

In these 4 seasons,the Randi family has certainly optimized the technical management of the vineyard in the best possible way, saving tons of water, hours of manpower and above all 20% of chemical product (or active ingredient) used for both contact and systemic chemicals, in every treatment.

Above all, they have reduced the phytosanitary defence operations to only 2 days, enabling them to concentrate and aim the remaining hours of manpower at other activity within the company.

Finally, it gives us great pleasure to report that, for some years, the Randi company has been part of the Bagnacavallo consortium which is the producer and distributor of the well known “Burson” (http://www.vinography.com/archives/2004/07/2000_burson_rosso_ravenna_cons.html ) wine obtained from “Longanesi” grapes.

For further information on the Randi company, visit www.randivini.it and/or send an email to info@randivini.it

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1. Mr. Rey Rademeyer Junior of the Delarey Rademeyer Trust Farms in South Africa
2. Interview with Mr. Rolando Bettarini, owner of the Tuscany based wine farm “Fattoria di Piazzano”