Dose per hectare of leaf wall area

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Foliage wall surface in a vineyard with trellis training.

The dose per hectare canopy area is the amount of a pesticide, the per hectare to the foliage wall surface ( Leaf Wall Area to the plant surface to protect is to be applied, LWA) at room culture (vineyards and orchards), adequately against disease and pest infestation. The reference here is to the foliage wall area and not to the base area; the foliage is the actual treatment area.

initial situation

High foliage wall of a high culture with drooping shoots.
Difference in foliage wall area from two different training systems at the same development time.

In the vine there is a significant change in the development of shoots and leaf areas during the growing season. This also means that a rising area of ​​foliage must be protected during the year. Furthermore, it should be noted that vine training systems are very different. Both the distance between the rows and the distribution of the cut annual wood have a major influence on the development of the canopy (see Fig. Canopy development) and distribution during the year. The larger the surface has developed through growth, the more product quantity has to be applied.

The sum of all green parts of the vines (leaves, shoots, berries) reaches a surface of approx. 30,000–40,000 m 2 / ha , depending on the vigor, variety and type of training . The fluctuation range of the surface is strongly influenced by the training system used, the row distance and the height and structure of the canopy. There is a very high correlation between the shoot length and the leaf area (r 2 = 0.91). The differences between varieties and growing areas are small. With increasing shoot growth, the leaf area increases in the same proportion. The amount of pesticides can therefore be increased linearly with increasing shoot length (= canopy height). This connection is of great importance in practice and makes implementation easy.

Sprayers in viticulture and fruit growing do not treat the floor area. The fan air flow and the nozzles are directed towards the leaf wall. Therefore the leaf wall is the actual treatment area and not the base or the ground. The treatment of the foliage wall is to be understood as tape spraying, with the two treatment surfaces being perpendicular.

Furthermore, this system of dosing, which according to EU regulations should enable a simple transfer of approvals, is a good way of simply transferring approvals. This transfer is currently not possible with the hectare application rates for spatial crops.

Calculation of the foliage wall area

Development of canopy wall areas of vineyards depending on different canopy heights and row distances

The canopy wall area (the treatment area) is calculated from one hectare with the row spacing and the canopy wall height:

LWA = Leaf Wall Area = canopy wall area in ha (is the area to be sprayed, which results from the multiplication of the row length × canopy height × 2 (both sides of the canopy). Do not confuse this term with the leaf area of ​​the culture.)
R = row spacing in m
LWH = height of foliage wall in m

The information is given in kg / ha or l / ha of leaf wall area. This information remains the same over the period of application. This means that in the case of future plant protection product approvals for spatial crops (viticulture, fruit growing, certain greenhouse crops) there will only be one indication, namely kg / ha or l / ha of leaf wall area. An adjustment will be made to the existing approvals.

If the winegrower had to know or determine the water output / ha of the spraying device when applying the hectare expenditure (kg / ha or l / ha), the water output of the spraying device per hectare of leaf wall area must be calculated or determined for kg / ha or l / ha of leaf wall area . This is usually 400–500 l water / ha / leaf wall area.

Advantages of a canopy-related dosage

A canopy-related application takes into account:

  • Differences in the stages of development of grape varieties (growth, internodal length). For example with the Dornfelder variety . Due to the shoot length and height, it already has a significantly higher development than Silvaner or Kerner . As a result, one more nozzle has to be switched on to cover the current height of the canopy.
  • Different row spacing.
  • Various education systems such as minimum cut education , Vertikoerziehung , Pergelerziehung u. a.
  • Different shapes of the cut vine wood such as half and flat arch cuts .
  • The relationship between the application rate per unit of leaf wall area and the covering mass is taken into account. There is a clear relationship between the unit of treatment area (square meters of leaf wall area) applied product amount and the average covering mass (µg active ingredient / cm 2 leaf or berry surface). The baseline-related system does not take this into account.
  • The application device does not have to be readjusted from system to system with different row spacings.
  • A treatment of the grape zone or the foliage zone as a separate treatment band as a partial area treatment is possible with the same setting.
  • Product application rate and water application rate are decoupled from one another. It is up to the winemaker which amount of water (l / ha of foliage wall area) he chooses within the specifications of the instructions for use.
  • Use of a spray computer - this can implement the dosing equation based on the treatment area.

Others:

  • The use of a recycling device is also unproblematic. Regardless of the system, there is no need to change the preparation of the spray mixture. The broth losses collected are reused. With the amount of broth - in accordance with the recycling factor - a larger area of ​​leaf wall can be treated.
  • It is not necessary to retrofit application devices.
  • All nozzle stations should have the same nozzle size so that there is a rectangular vertical distribution of the spray liquid on the foliage wall.
  • The approval procedure will be simplified and will only be interchangeable between countries.

literature

Individual evidence

  1. ↑ R. Wohlhauser: Leaf Wall Area as a reference area for the dosage of pesticides in room crops - influence on the dose-effect relationship in field tests as well as the European pesticide approval . (PDF) Summer conference, Dummersdorf June 28, 2012 (lecture presentation).
  2. ↑ Barbara Friedrich, Martin Mehofer, Gerald Kneissl, Daniel Hugl, Erhard Kührer, Hand Köstner, Josef Klement, Verena Klöckl, Karl Bauer: Viticulture Recommendations 2015 . Austrian Viticulture Association, 2015, pp. 55–56.
  3. ↑ Helmut Redl: Quality improvement in the use of vine protection agents . In: The winemaker. No. 4, 2013, ISSN  0043-5953 , pp. 9-15.
  4. ↑ Heribert Koch: Targeted and effective use of pesticides - a new dosage model makes it possible. In: Innovino: Magazine for modern viticulture. No. 2, 2012, ZDB -ID 2301335-7 , pp. 16-17.
  5. ↑ Sum of all leaf tops and bottoms + surfaces of green shoots, tendrils and grapes.
  6. ↑ Sheet area only measured once and not the top and bottom together.
  7. ↑ Werner Siegfried, Mirjam Sachelli, Oliver Viret, Ron Wohlhauser, Urs Raisigl, Bernhard Huber, Roland Ipach, Gerhard Bäcker: Dosage of plant protection products based on leaf area in viticulture . In: Swiss magazine for fruit and viticulture. No. 4, 2005, pp. 13-16.
  8. ↑ Gabriele Kovacs, Ingrid Langer: Evaluation of the efficacy and approval of plant protection products in viticulture , lecture vine protection area manager conference 2015, AGES Vienna.
  9. ↑ leaf area = sum of all leaves per hectare in m 2 ; Leaf surface = sum of the top and bottom of the leaves per hectare in m²; In plant protection, all green plant parts are usually included in the surface information.
  10. ↑ Heribert Koch, Oliver Strub, Georg Hill: How should crop protection agents be correctly dosed? In future, based on foliage wall area instead of floor area . DLR RheinhessenNaheHunsrück– LW 23, 2013.