FAQs – Frequently asked questions and answers

Frequently asked questions about the use of Lechler nozzles and nozzle systems in agriculture and the corresponding answers can be found in the following compilation.


  • What is the meaning of CV (Cross distribution)?

    CV is the coefficient of variation and describes the evenness of the liquid distribution along the boom. In some countries this is a criteria in the mandatory sprayer check and has to be below 10%.

    Lechler nozzles match the even higher German JKI guideline for new nozzles of being below 7% at all spray heights (120° nozzle: 40 – 50 – 60 cm) and pressure settings (depending on the nozzle type; the pressure range for a nozzle type is mentioned in our catalogues).

  • 110 degree nozzles versus 120 degree nozzles – What are the benefits?

    The 120° spray angle gives a better overlap along the boom at the recommended 50 cm boom height above the target when compared to 110°.

    Therefore, the coverage and evenness of the spray is better, even there might be some variation of height during spray operation due to either boom movement or rolling field.

  • By which material Lechler plastic nozzles are manufactured?

    Lechler plastic nozzles are manufactured from high performance POM.

    The material shows excellent wear resistance as well as chemical resistance against all common used plant protection products and liquid fertilizers.

  • What is the life expectancy of a plastic nozzle compared to ceramic nozzle?

    Wear always depends on pressure and the liquid going through a nozzle.

    At higher spray pressure, higher wear is observed. If more powder products or water with quicksand from a well are sprayed, there are more small particles in which will cause more abrasion. Several field tests show, that the lifetime of a ceramic tip can easily be 2 to 3 times higher compared to plastic.

  • Online-shop Lechler – Who can order?

    Industrial customers have access to the Lechler Online Shop. There is no online shop for agricultural nozzle technology.

  • Clogging of the nozzle – How to avoid clogging? How to clean correctly?

    When should nozzles be cleaned?

    • If they show a visually uneven spray pattern (spray)
    • Before wintering

    How are nozzles cleaned properly?With a nozzle brush or toothbrush

    • Blow through with compressed air against the spray direction
    • Support: Soak in common sprayer cleaner (no acid!)
    • Ultrasonic bath

    Avoiding contamination/clogging:

    • Rinse promptly after use e.g. use continuous cleaning
    • Pay attention to the mixing order of the agents (see recommendations of chemical companies
    • Decalcify or add rainwater to very hard water
    • Pay attention to a good agitator function in the spray tank   
    • Use adequate nozzle strainers – see recommendations on spray tables

    Recommendations and practical experiences are summarized in our article "It doesn't work without nozzle cleaning".

  • Filter mesh sizes – Which is the correct nozzle strainer size? Which is the correct pressure filter size?

    The suction filter (pump protection) must always be coarse (25 M). The pressure filter must take over the main filter performance in the system – large filter area, flushing possible. For small nozzle sizes and without a nozzle strainer, an 80 M pressure filter (ISO color yellow) is recommended.

    In general the use of nozzle strainers is recommended. The recommendation of the correct nozzle strainer size (25 M, 60 M, 80 M) can be found in our spraytables depending on the nozzle size.


  • Which factors significantly influence the droplet spectrum?

    A spray nozzle atomizes liquid into droplets of different sizes. The range from the smallest to the biggest droplet represents the droplet spectra.

    The droplet spectrum is influenced by several factors:

    • Type of nozzle (hollow cone, flat jet, double flat jet, etc.)
    • Spray angle
    • Spray pressure
    • Surface tension of liquid
    • Viscosity of liquid
    • Density of liquid


    The volumetric mean diameter (VMD) of the spray decreases with increasing spray pressure and spray angle, decreasing viscosity and surface tension, and increasing density of the liquid.

    As the viscosity of the liquid and the spray angle decreases, the drop size spectrum becomes narrower.

  • Which advantages offer pulse width modulation (PWM)?

    PWM can be used to control the flow rate of a nozzle on a sprayer. Due to the fast closing and opening (10 – 30/sec) of the valve, the flow rate is controlled precisely, varying amounts of spray liquid are applied at the same pressure and maintaining droplet size with just one nozzle size.


    • Single nozzle switching and control with variable flow rate
    • Constant droplet size and application rate with variable operating speed
    • Drift reduction and consistent coverage at constant droplet size
    • Curve compensation to avoid underdosing and overdosing at the outer and inner part of the boom, e.g. when driving around obstacles and cornering
    • Variation of the application rate for site-specific application
    • Large range of flow rate of a nozzle without significant change of droplet size
    • Spot spraying – for small-scale application of crop protection products on the spot

Applications – Plant Protection

  • Which nozzle perform best for control of black-grass?

    For pre and post emergence applications double flat fan nozzles avoid spray shadows e.g. on cloddy soils and cover the small vertical leaves of black grass on both sides in direction of travel.

    IDKT: The two symmetric fans, one 30° to the front and the other 30° backwards for sprayer speeds up to 12 km/h.

    IDTA: asymmetric fans, one 30° to the front and the other 50° backwards for sprayer speeds of 10 km/h and higher.

  • What is the difference between double flat fan nozzles and flat fan nozzles?

    Twin flat spray nozzles

    • Very good coverage in open canopies and upper third of the canopy
    • Avoidance of spray shadows
    • Very good deposition on vertical surfaces

    Flat fan nozzles

    • Very good penetration
    • Very good deposition into the lower parts of the crop canopy

    Whenever small vertical targets needs to be covered (e.g. black-grass), twin flat fan nozzles provide better coverage. Furthermore, spray shadows are avoided in case of small herbs or cloddy soil. Also, ear treatment, potato desiccation show better results with twin nozzles, too.

    Further information:

    IDTA nozzle

    IDKT nozzle

    Nozzle recommendations


  • Is an air injector twin nozzle more likely to clog compared to a standard air injector nozzle due to the two smaller exit orifices, e.g. 04 twins = 2 x 02 exit orifices?

    For sure, in an air injector twin nozzle the fan forming orifices are smaller compared to a standard air injector fan orifice. A 04 twin does have about two times 025 exit orifices.

    The amount of water, which goes through the air injector nozzle, is determined by the dosing orifice at the top of the nozzle and not by the nozzle tip. The dosing orifice matches the flow rate of ISO standard. The orifice to form the fan is always bigger at a standard air induction nozzle.

  • What is the difference between IDTA and IDKT?


    • Symmetrical double flat spray nozzle 30°/30° to the front and rear in direction of travel, recommended up to 12 km/h
    • Drift stable up to 3 bar
    • Medium to ultra coarse drop application for optimum coverage (e.g. small weeds in sugar beet, grasses in cereals, etc.)
    • 90% drift reduction – IDKT 120-02 to -06


    • Asymmetric double flat spray nozzle 30°/50° to the front and rear in direction of travel, recommended from 10 km/h and faster
    • Drift stable over wide pressure range
    • 95% drift reduction – IDTA 120-05
    • 90% drift reduction – IDTA 120-025 to -04

    Both Lechler double flat fan nozzles operate deliberately with a 30° spray angle to the front and hence against the air drag and wind. This ensures an optimum deposition and coverage on the front of the crop. The flater 50° spray angle to the rear of the IDTA ensures the spray coverage at higher travel speeds above 10 km/h on the rear side.

    Further information:

    IDTA nozzle

    IDKT nozzle


  • What is the difference between long air injector nozzles (ID, IDN, ID3, IDTA) and compact injector nozzles (IDK/IDKN, IDKT)?

    The nozzle series differ in the length of the nozzle body and therefore in the size of the injector.

    The long version air injector nozzles ID3 and IDTA work over a bigger spray pressure range and remain coarse even at 8 bar. The recommended spray pressure range is 4 – 8 bar.

    The compact version air injector nozzles IDK/IDKN and IDKT work ideally drift stable at the lower spray pressure range from 1.5 – 3 bar. At higher spray pressure the fine droplet fraction increases and causes drift under unfavourable weather conditions or higher forward speeds.

    Long air injector are much more flexible in use and drift stable with regard to changing forward speeds or l/ha rates. The compact air injector nozzles (IDK/IDKN, IDKT) have a narrower usable pressure range and "mist" earlier.

  • What are the advantages and limitations of IDKT and IDTA nozzles?

    Advantages IDKT

    IDKT 120 is a symmetrical double flat spray nozzle in compact design and in sizes 02-06 with approval of 90% registered in the JKI directory for loss reducing technology. It achieves very good coverage of small grasses/herbs or on vertical surfaces – the double flat fan reduces effectively spray shadows. Optimum pressure 1.5 – 3 bar, at pressures >3 bar can be applied deliberately medium droplets to hit smallest targets. Optionally available in plastic (POM) or ceramic (size 03-06).

    Advantages IDTA

    As an asymmetric double flat jet nozzle, especially advantageous for speeds >10 km/h to reduce spray shadows here as well. As a long nozzle at 3 – 8 bar, even when the pressure is increased, there is little change in the droplet spectrum. Reduced spray angle to the rear compensates for the longer "trajectory" of the droplets – no overspray of the field edge, plus wind stable.

    Limits IDKT

    Ideal in the low pressure range of 1.5 – 3 bar. At higher pressures > 3 bar, medium droplets and low drift reduction. Canopy penetration is less compared to a single-fan IDK/N.

    Limits IDTA

    At 3 bar and higher, very good deposition. Canopy penetration is less compared to a single-fan ID.

  • What are the differences and limitations of an 80/90 degree nozzle compared to 110/120 degree nozzle on a boom sprayer?

    80°/90° flat spray nozzles are suitable for 25 cm nozzle spacing along the spray boom. Most of these nozzles are made of ceramic. 110°/120° flat spray nozzles are suitable for either 25 cm or 50 cm nozzle spacing along the spray boom. Most of these nozzles are available in plastic (POM) and ceramic (C).

  • Double flat spray nozzles – The nozzles in the mid-section of the boom are spraying on the sprayer frame. What can I do?

    If the boom height is low in case of autumn or spring herbicide/first fungicide application, the front spray jet of the twin nozzle hits no implement parts – consistent use of the double fan technique is possible. At higher boom position and small distance between the nozzles and the sprayer frame it is possible to spray on sprayer parts.


    • Slightly twist the centre nozzle pipe or
    • Replace the air injector double flat spray nozzles in the middle section (4 – 6 pieces) with air injector single fan spray nozzles – mixed equipment. The coverage quality in this area is also ensured with single-jet nozzles as the plants are shaken when driving over high vegetation and therefore are also covered optimally. This mixed spray system is officially approved by the JKI and registered as drift-reducing application technique.
  • 25 cm nozzle spacing on a boom sprayer – Advantages/disadvantages

    Originally developed for the application of fertilizer with drag hoses, the application of crop protection products with reduced nozzle spacing have been increasingly propagated during the last years. The aim is to reduce drift with good boom guidance and a low target distance – the target area distance has a major influence on drift. JKI-approved nozzles with 120 degree spray angle work up to 40 cm target distance at 50 cm nozzle distance with good lateral distribution. Even at 25 cm nozzle spacing, these nozzle types can work individually (every 50 cm, for example, at slow travel or low l/ha rates) or in any combination with other 120 degree nozzles at faster travel or higher water rates. The minimum and maximum heights of the JKI approval can be applied. Nozzles with the same optimal pressure range should be combined (e.g. 2 x "short" or 2 x "long" nozzles). In case of lower target area distance of less than 40 cm, the nozzle output must be the same every 25 cm / same nozzle size as e.g. IDK 90-015/02 or also 2 x an 03 nozzle with 120 degree spray angle.


    Reduction of drift if the boom is guided safely at 50 cm or less, "nozzle gear" (switching) for optimum nozzle size/pressure depending on requirements, nozzle change from the cab.


    With slow travel/low water quantities also "only" 50 cm nozzle spacing possible, as otherwise the nozzle size becomes very small. Good filtration and equipment hygiene are necessary, as smaller nozzle calibres are used.

  • I would like to equip my vineyard/fruit sprayer with drift-reducing nozzles. Which nozzles should I use?

    Recommended Lechler drift reducing nozzles for the use in air blast sprayers are flat spray types like ID 90, IDK 90 and AD 90 as well as the hollow cone type ITR 80. The compact IDK 90 injector nozzle results in a high biological efficacy through coarse to medium droplet application at 8 – 15 bar. At the same time, depending on the blower type, up to 95% drift reduction is possible.

    If contact agents are used primarily (e.g. organic farming) the AD 90 series is recommended. Depending on the spray pressure, a coarse, medium to fine droplet application improves the coverage. In addition, the flow velocity in the nozzle is very high, which makes the nozzle very robust even with difficult spray tank solutions or mixtures.

    You can select the right nozzle size with our nozzle calculator for orchards, viticulture, specialty crops.

    Lists with drift reducing nozzles and combinations of blower types for different countries are available in our support section.

Applications – Liquid Fertilization

  • Lechler FD nozzles are "fan" type nozzles – are these nozzles more likely to cause crop damage in comparison to dribble bars or stream type nozzles?

    The droplet spectrum of the Lechler FD fertilizer nozzle is extreme coarse and comparable to the drop size of stream nozzles.

    The main advantage of FD is to release the droplets almost horizontal at a low pressure, so they fall into the canopy just like rain by gravity. This is an important advantage when applying liquid fertilizer. Often times scorch is caused by mechanical damage of the waxy layer due to high kinetic energy and impact in the droplet or stream. This even more if application takes place after a rainy period or when there is a lot of dew in the canopy, which weakens the waxy layer.

    For late fertilizer applications when the crop is already big (e.g. late application in cereals), it is recommendable to use a hose drop system like 5S and 5SL or the DroplegUL. With those systems, damage can be avoided because the fertilizer is applied into the canopy and not on the top of the crops.

    Further information:

    FD nozzle

    Nozzle recommendations

  • What are the advantages of the VR nozzles compared to the FD nozzles?

    Advantages VR

    • Liquid fertilizer nozzle with variable flow rate
    • Covers 5 FD ISO sizes
    • Flexible application rate at changing forward speeds without changing nozzles
    • Suitable for precision farming

          Disadvantage VR

    • Superfluous with multiple nozzle carriers
    • Only recommended for units with variable volume flow control
  • Is it possible to apply liquid Fertilizer with a PRE (Pre-emergence) nozzle?

    Yes. In contrast to FD nozzles which are not approved or suitable for crop protection applications.

  • What conditions should prevail when applying liquid fertilizer?

    Optimal conditions for proper UAN applications are:

    • Temperature range between -5° C and 25° C
    • Frost-dry plants (however, avoid alternating frost conditions)
    • Preferably application → Wax layer formed to avoid leaf necrosis
    • After a rainy period, wait 1-2 days for sufficient wax layer to form
    • Application for sowing until 3 days after
    • Mixtures of UAN with water at least in a ratio of 1:3, better 1:4.

    Application technique requirements:

    • Coarse droplet application at low pressure - possible with liquid fertilizer nozzles up to 4 bar → drops should roll off towards the ground
    • UAN pure in combination with a herbicid should be applied with ID or IDK/IDKN nozzles up to max. 200 l/ha. Observe the pressure recommendations of the nozzles.
    • For application of UAN pure VR/FD/PRE or FS nozzles are recommended
  • Which technique is used to properly apply liquid fertilizer?

    VR, FD and FS/FL nozzles

    Recommended at the beginning of vegetation period and in open crop canopy. Ideal application with the extremely coarse droplet VR / FD nozzle with best lateral distribution.

    FL or FS (five-orifice nozzles)

    These nozzles are also extremely coarse-dropping. Fertilizer nozzles are recommended in fall and spring up to BBCH 49. Please follow professional practice.

    Hose drop systems  5S, 5SL

    For late fertilizer applications e.g. quality application in cereals or for safe application in damp and dewy canopies.


    Suitable for plant-friendly fertilization in cereals and row crops e.g. corn, sunflowers, etc. – equipped with FL nozzles; no floating over the canopy even at higher forward speeds results in higher work rate.

    ID3 or IDK/IDKN

    Recommended only at lower pressure range for UAN pure or in combination with a herbicide. Also late foliar application with diluted UAN (ration 1:3 or 1:4 or max. 30 l UAN/ha).

FAQs Industrial Sector

We have summarized our FAQs in the industrial sector separately and clearly for you:
FAQs Industrial Sector