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Abstract Dose expressions are highly variable within the european Union. recommended doses in high growing crops are expressed in various ways on product labels. therefore it is necessary to harmonize the dose expres-sion in high crops. in future one model should be favored, preferably the leaf wall area (lWa) approach. the doses in the lWa model are expressed in kg or l per 10.000 m² leaf wall area. this is the basis for canopy-adjusted dose determination in all high crops.
the leaf wall area (lWa) is a function of the canopy height and the row spacing. the canopy height will be de-fined as the average distance from the highest leaf to the deepest leaf of a tree.
in this publication first results of the determination of lWa in different German fruit farms with commercial ap-ple plantations are presented and discussed.
the lWa as well as the incremental growth depends on the rootstocks and the varieties. the measured figures vary from approx. 8000 m² for new planting to approx. 19000 m² for older orchards.
Keywords leaf wall area · Dose rate expression · Dose rate determination · spray volume · Fruit crops
Dosiereinheiten – Notwendigkeit zur Harmonisierung und der Konsequenzen des Laubwandflächenmodells
Zusammenfassung Die Dosiereinheiten sind in der euro-päischen Union sehr unterschiedlich. Die empfohlenen
aufwandmengen in raumkulturen sind in verschiedenster Weise in den Produktinformationen ausgedrückt. eine har-monisierung der Dosiereinheiten in raumkulturen ist drin-gend erforderlich. Zukünftig wäre eine einheitliche Dosier-angabe wünschenswert, vorzugsweise die laubwandflä-chen berechnung (lWa). Die Dosis wird im lWa Model als kg je 10.000 m² laubwandfläche angegeben. Dieses stellt die Grundlage für die Dosierung in allen raumkultu-ren dar. Die laubwandfläche (lWa) ist eine Funktion aus laubwandhöhe und reihenentfernung. Die laubwandhö-he kann als durchschnittliche entfernung vom niedrigsten zum höchsten blatt eines baumes definiert werden.
in dieser Veröffentlichung werden erste ergebnisse von laubwandflächenbestimmungen aus verschiedenen deut-schen Obstbetrieben mit professionellen apfelanlagen vor-gestellt und diskutiert.
Die laubwandfläche wie auch der jährliche Zuwachs hängen von den sorten und den verwendeten Wurzel-unterlagen ab. Die gemessenen Werte schwanken von ca. 8.000 m² bei Neupflanzungen bis hin zu 19.000 m² bei älteren anlagen.
Schlüsselwörter laubwandfläche · Dosiereinheit · Dosis bestimmung · spritzvolumen · Früchte
Introduction
the unit and the dimension of the dosage are extremely important for carrying out and assessing field trials—this is relevant for professional applications as well. the trial results collected over several years are important for the registration and must reflect the practical application sce-narios in orchard plantations. the data from the registration trials of plant protection products (PPP) influences primar-
erwerbs-Obstbau (2012) 54:49–53DOi 10.1007/s10341-012-0161-z
Dose Rate Expression—Need for Harmonization and Consequences of the Leaf Wall Area Approach
Ralph-Burkhardt Toews · Reinhard Friessleben
r.-b. toews () · r. Friesslebenbayer cropscience aG, alfred-Nobel-str. 50, 40798 Monheim, Germanye-mail: [email protected]
received: 13 april 2012 / accepted: 17 april 2012 / Published online: 1 June 2012© springer-Verlag 2012
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ily label instructions, which are legally binding for the user (koch 2007). these dose expressions differ substantially in europe for the time being. this can influence residues and can have effects on the environment, so harmonization is necessary to improve mutual data exchange for PPP regis-tration und practical use. a harmonized dose expression method ensures also complete and identical information for growers (koch 2007).
the ePPO guidelines of 2005 permit various dose rate expressions (ePPO 2005). the Zonal registration and the revision of the ePPO guidelines expedite the process of harmonizing dose rate expression in high growing crops in europe. the intention is not only to make test results and registrations more comparable and usable in the registra-tion zone, but also to establish a understandable and simple calculation for practical use that replace the older, more insufficient models like % concentration, kg/ha or kg/ha* m canopy height. in future it’s recommended that the dose rate expression should be defined by the leaf wall area model.
therefore, the following questions have to be answered:
1. What is the right method to measure the leaf wall area?2. how increases the lWa during the vegetation period?3. how large are the actual leaf wall areas in professional
orchards?
in this publication selected German orchard plantations have been evaluated to answer these questions.
Definition of Dose Rate Expression LWA
the dose rate determination is one of the most important and most difficult steps during the development of a PPP. the dose rate defines the amount of an active ingredient pla-ced as an initial deposit on the target area, which is adequate to control a certain target organism.
We must distinguish between:
• Dose expression: the unit in which the dose is expressed on the label
• Dose adjustment: the determination of a crop and or pest adjusted dose, i.e. the quantity of product, necessary to achieve requested efficacy results under specific cir-cumstances (koch and Weisser 2002; Friessleben et al. 2007)
Dose expression and dose adjustment are two related but different tasks (koch 2007). the determination of crop-ad-justed dose will not be considered by changing dose rate expression.
spraying machines deliver a certain water volume to a virtual treated area of e.g.10.000 m². in high crops this area cannot be the ground area like in arable crops.
sprayer calibration formula:
the treated area is defined by the area that is covered by working nozzles. the nozzles overspray a vertical plane, defined by row length and spray swath height (koch and Weisser 2000) from both sides of the tree row. the over-sprayed area is the treated area (Fig. 1).leaf wall area is expressed by the following formula
(Friessleben et al. 2007):
row distance and canopy height are the key figures for cal-culating the leaf wall area. each change of 10 cm causes a 3–5 % change of the lWa. Due to this the determination of the canopy height should be described exactly in order to establish a uniform and reproducible method. the canopy height can be defined as the distance between the highest and lowest leaf or fruit of a tree (Fig. 2). in some crops like e.g. bush berries also the stem or cane can belong to the target area and thus to the canopy height.
Water volume (L 10 000 m−2)
=Nozzle flow rate (L min−1) × number of nozzles × 600
Working width (m) × travel speed (km h−1)
Leaf Wall Area (LWA) m2 = 2 × Canopy height (m)
×ground area (m2)
row distance (m)
Fig. 1 treated area—defined as the area that is covered by working nozzles. (source: koch, h., Dlr bad kreuznach)
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51Dose rate expression—Need for harmonization and consequences of the leaf Wall area approach
Due to the fact that orchards are not always uniform, we recommend to measure the canopy height on 20 randomly distributed orchard trees and to calculate the average. the measurement is preferred compared to an estimation or stan-dard assumption. the size of the sample (amount of measu-red trees) determines naturally the accuracy of the average value. in view of an acceptable, feasible procedure for the growers or advisors this sample size should be sufficient.
Seasonal Change of the Leaf Wall Area
During the vegetation period in 2011 three varieties (‘Gol-den Delicious’, ‘red boskoop’, ‘Pinova’) in 7 different orchards were assessed at the bayer cropscience experi-
mental farm in höfchen. a summer pruning was not carried out. the row spacing amounts to 3.5 m.
an increase of the leaf wall area from april to the end of august of approx. 20–30 % was observed by varieties with the weak root-stock M 9 irrespective of varieties.
On the other hand, an increase of the lWa of 65 % was determined by varieties grafted on invigorating root-stock M 7. the leaf wall area was still in april in all orchards approx. 11.000 m². the lWa after shoot growth of the varieties grafted on M 9 varied only little and was bet-ween 13.486 m² (‘red boskoop’) and 14.114 m² (‘Golden Delicious’).
comparing the influence of the root-stocks on the deve-lopment of the lWa of ‘red boskoop’ on M 7 was around 4.000 m² higher than on M 9. ‘red boskoop’ showed the highest leaf wall area of about 17.000 m² with M 7. the lWa of ‘Golden Delicious’ on MM 106 increased from 14.171 m² up to 16.571 m² on root-stock M 7.
the increase of the lWa is based predominantly on the shoot growing upwards. the tree height increased between 20 and 48 cm on root-stock M 9. the root-stock M 7 cau-sed an increase of 65–115 cm canopy height. Due to the increase of fruit weight the lower branches bend down bet-ween 2 and 20 cm.
Fig. 2 Measurement of canopy height
m canopy height,distance from highest leaf to the lowest leaf
Table 1 increment of lWa of apple orchards 2011, bayer cropscience trial station höfchenQuartier Planting year rootstock Variety Date of
assessmentbbch row
spacingcanopy height (cm)
lWa (m²) rel
Qu 30 1999 M 9 Golden Delicious 15. apr 52 3.50 190 10.743 10017. Mai 65 3.50 210 11.714 10915. Jul 71 3.50 210 12.171 11326. aug 77 3.50 250 14.114 131
Qu 5c 1969 M 9 red boskoop 15. apr 52 3.50 190 11.029 10017. Mai 65 3.50 200 11.429 10426. aug 77 3.50 240 13.486 122
Qu 5c 1969 M 7 red boskoop 15. apr 52 3.50 190 10.571 10017. Mai 65 3.50 230 12.857 12226. aug 77 3.50 310 17.429 165
Qu 5c 1969 MM 106 Golden Delicious 15. apr 52 3.50 190 11.029 10017. Mai 65 3.50 210 12.000 10926. aug 77 3.50 250 14.171 128
Qu 5c 1996 M 7 Golden Delicious 15. apr 52 3.50 190 10.857 10017. Mai 65 3.50 220 12.457 11526. aug 77 3.50 290 16.571 153
Qu Xii 2005 M 9 Pinova 15. apr 52 3.50 200 11.429 10017. Mai 65 3.50 220 12.686 11126. aug 81 3.50 240 13.657 119
Qu Vi 2010 M 9 Pinova 15. apr 52 3.50 110 6.286 10017. Mai 65 3.50 140 7.829 12526. aug 81 3.50 150 8.286 132
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52 r.-b. toews, r. Friessleben
a ‘Pinova’—new planting (block Qu Vi) was included into table 1. here the lWa increase to approx. 6.300–8.300 m² at the end of the growing season (32 %).
the measurements will be continued in the next year and supplemented by additional locations.
Determination of the LWA of a Professional Fruit Farm
in the most important German orchard growing areas determinations of the lWa in professional fruit farms have been conducted. in table 2 the data are shown for a larger fruit-growing farm in the region of thuringia in 17 apple orchards with seven varieties and two root-stocks. the leaf wall area of M 9 root-stocks differs variety-dependently between approx. 12.000 and 18.000 m². the highest lWa was measured in ‘Golden Delicious’. the root-stock M 26 showed a 11 % higher leaf wall area in relation to M 9 with ‘idared’ and around 24 % with ‘Pinova’, despite the wider row spacing of 3.5 m for the M26 rootstock. the maximum lWa was measured in ‘Pinova’ on M 26 rootstock with 19.429 m².
it was shown that the leaf wall area differs depending on variety and root-stock. therefore the dose determination has to be different for each variety depending on the lWa, which has effects on the adjustment of the spray equip-ment. these requirements are not only relevant for the lWa approach but concern all dose expression calculations.
a successful implementation and acceptance of the lWa method by farmers and advisors depends on a good educa-tional advertising and training.
Outlook
the data analysis in professional farms has to be continued in the next year. the aim is to get a broad overview of the current lWa in europe and its consequences for the regis-tration of PPP, field trials on efficacy and growers spray application. For this the use of geo data from the land sur-veying has to be proven. some approaches like the “air-borne laser-scanning” might be able to determine tree height and row width. this method uses special laser scanner sys-tems mounted on manned or unmanned airplanes to scan the ground surface. Geo data can possibly supply huge data sets in a relative short time frame. Further investigations within europe and other crops than apple should follow.
For a successful implementation of the lWa method into the registration process of PPP and also into practical use it is necessary to clarify the determination of the lWa for special cultivation forms and crops. the main question is: how can the lWa concept be converted in all orchards, viti-culture and high growing vegetables?
training of trial officers, advisors and professional users are necessary for a broad consent. For this plan appropriate concepts must be still compiled.
Table 2 leaf wall area of apple orchards of a thuringia fruit farm 2011block Planting
yearrootstock Variety Date of
assessmentbbch highest
leaf (cm)Ground clearance (cm)
canopy height (cm)
row spacing (cm)
lWa (m²)
3 2008 M 9 Jonagored 07. sept 87 260 32 228 330 138293 2008 M 9 elstar 07. sept 87 247 50 197 330 119399 1997 M 9 Pilot 06. sept 87 269 40 229 320 142815 1991 M 9 Pilot 06. sept 87 263 44 220 320 137195 1991 M 9 Golden Delicious 06. sept 85 290 30 261 320 162815 1991 M 9 elstar 06. sept 87 275 50 225 320 140638 1995 M 9 Golden Delicious 07. sept 85 320 30 290 320 181258 1995 M 9 Pinova 07. sept 81 295 30 265 320 165636 1989 M 26 idared 07. sept 85 303 23 280 400 140006 1989 M 9 idared 07. sept 85 283 30 253 400 126257 2003 M 26 Pinova 07. sept 81 370 30 340 350 194295 1991 M 9 Pinova 06. sept 81 287 36 251 320 156564 2010 M 9 shampion 07. sept 89 170 60 110 320 68752 2009 M 9 shampion 07. sept 89 266 60 206 350 117431 2009 M 9 shampion 07. sept 85 278 60 218 320 136255 1991 M 9 shampion 06. sept 85 276 41 235 320 146889 1997 M 9 shampion 06. sept 85 282 38 244 320 15250
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53Dose rate expression—Need for harmonization and consequences of the leaf Wall area approach
References
ePPO (2005) efficacy evaluation of plant protection products. Dose expression for plant protection products. ePPO bulletin 35:563–566
Friessleben r, roßlenbroich h-J, elbert a (2007) Dose expression in plant protection field testing in high crops: need for harmoniza-tion. Pflanzenschutz-Nachrichten bayer 60:89–96
koch h (2007) how to achieve conformity with the dose expression and sprayer function in high crops. Pflanzenschutz-Nachrichten bayer 60:71–89
koch h, Weisser P (2000) sensor-equipped orchard spraying—effi-cacy, savings and drift reduction. aspects of applied biology 57, advances in Pesticide application, pp 357–362
koch h, Weisser P (2002) expression of dose rate with respect to orchard sprayer function. aspects of applied biology 66, inter-national advances in Pesticide application, pp 353–358
