Xylem flux or transpiration was measured in situ using the heat balance method on eight 4-year-ol... more Xylem flux or transpiration was measured in situ using the heat balance method on eight 4-year-old 'Braeburn' apple trees (4.9 m 2 leaf area) during summer 1999 at Klein-Altendorf experimental station near Bonn, Germany. The apple trees consumed from 70 ml of water per night per tree on cool summer nights to 180 ml water on warm summer nights. During the day, the apple trees transpired 1.7 litres per tree on cool, cloudy days and 4.8 litres on warm, sunny summer days. The midday depression in transpiration was more pronounced on sunny than on cloudy, cool days. The daily water consumption of the apple trees ranged from 1.8 to 5 litres water per tree, which was equivalent to 0.4-1 litres per day per m 2 leaf area. The best correlation was found between water consumption of the apple trees and water vapour deficit and, to a lesser extent, global radiation. These evaporation data now contribute to the weather fax and online service by the German National Meteorological Service (dwd), which supports growers in their decision making for irrigation based on meteorological data from dwd and evaporation values for fruit trees.
Measures for (a) improving the intensity of red colouration, and (b) increasing the proportion of... more Measures for (a) improving the intensity of red colouration, and (b) increasing the proportion of red peel on otherwise shaded parts of the fruit are reviewed with the aim of assessing their potential to meet consumer and market demands, produce healthier fruit and improve economic returns to the producer of bi-coloured apple and other fruits in the light of often unknown or under-estimated adverse side-effects of existing and new compounds mostly in the US in 2014; hence the underlying regulatory mechanisms of colour formation and inhibition in apple fruit are explained.Foliar fertilisers, used to enhance fruit colouration, so far had a limited effect principally in the order of 3–5 % better coloured fruit for most monophosphates—only ‘Seniphos’ (with 4 % CaO) consistently increased the proportion of well-coloured fruit by up to 8 %. Kaolin, a white particle film, appeared an unsuitable measure for improving fruit colouration at 50°N when sprayed onto the fruit, while it can significantly reduce sunburn at lower latitudes.Undesired side-effects such as lack of colouration can originate from misuse such as late application of excessive doses of 6-BA formulations, as otherwise properly used for thinning, or the gibberellin antagonist ProhexadionCalcium for shoot growth regulation. The mode of action is explained of colour promoting agents like methionin/phenylalanine (‘Sunred’), methyl jasmonate (‘Blush’), ethylene (‘Motivate’), aminoethoxvinylglycine (AVG, ‘Retain’) and abscisic acid (ABA, ‘ProTone’) although presently without registration in Europe.Light reflectors such as woven PE/PVP, aluminium-coated plastics, industrial-grade paper, straw, lime, kaolin, titanium oxide and lime-based compounds as mulch in the alleyways at least 4 weeks prior to anticipated harvest have been successfully used to enhance fruit colouration. They can particularly enhance the desired red colouration on the otherwise shaded green, (inner and lower) sides of the fruit. Colour improvements in the order of 8–10 % make reflective mulches particularly Extenday type PVP/PE/aluminium foils economically viable, particularly if used more than once a year. Light reflectors are more effective in years of poor colouration and in late ripening varieties, as intended; countryside concerns have to be considered.Cultivation measures at 50°N such as winter and summer as well as root pruning are the first steps to improve fruit (red) colouration by improving light penetration into the tree canopy and to the fruits, followed by light reflectors, ‘Seniphos’ like monophosphates, other fruit colour enhancing chemicals and evaporative cooling using overhead sprinklers at times of low humidity and little radiation (evening) and choice of lighter hail net (white or grey), hillsides (rather than valleys) and change to a variety with better colour. In any case, the greater content of anthocyanins in red apples provides an additional health benefit for the consumer without extra charge.
This work describes a new, computerised vision-based model to estimate the diameter and number of... more This work describes a new, computerised vision-based model to estimate the diameter and number of apple fruit on a tree and hence its yield autonomously under natural weather conditions in a fruit orchard. A charge-coupled device (CCD) camera acquired images of cvs ‘Golden Delicious’ and ‘Jonagold’ apple (Malus domestica L. Borkh.) trees seven times in the vegetation period, i.e. every two weeks from June to September 2007 for modelling the tree volume, fruit diameter and yield at harvest time. Images were processed off-line using image analysis for fruit colour, shape and texture. The fruit detection algorithm was successfully tested on trees bearing from 15 to 42 apple fruits and missed or mis-classified 1 to 3 apple fruits per tree. Fruit detection was sufficiently accurate with an 89 % rate and an overall error rate of 2.2 %. Fruit diameter was underestimated at the beginning of fruit growth in June, but the data corresponded closely (R2 = 0.96) with orchard measurements from Ju...
Apple leaf photosynthesis, measured by porometry, remained large at 814 µmol CO 2 m −2 s −1 and ... more Apple leaf photosynthesis, measured by porometry, remained large at 814 µmol CO 2 m −2 s −1 and was not limited by stomatal function after the commercial harvest date. The autumnal reduction both in photosynthesis and in vivo RUBISCO activity was less pronounced in ...
The objective of the study was to determine the carbon footprint for four farming and marketing s... more The objective of the study was to determine the carbon footprint for four farming and marketing systems, using primary data obtained on the farms for autumn pumpkin as an example and model crop. Area for the crop cultivation and weight, i.e. kilogram of saleable product, for the marketing phase were employed as the two functional units with system boundaries from
A higher frequency of hail storms, possibly due to climate change, has led to increased installat... more A higher frequency of hail storms, possibly due to climate change, has led to increased installation of hail nets worldwide. The objective of the present work was to investigate potential effects of the microclimate under these hail nets on micromorphological characteristics of the leaves and adaxial leaf cuticles. Leaves of apple cultivars 'Pinova' and 'Fuji' grown on trees under white (highly translucent) or red-black (low transmittance) hail nets or on uncovered (control) trees were evaluated in June, August, September and October. The microclimate under the colored hail nets had no impact on leaf micromorphology, amount of cuticular wax, or leaf thickness. Similarly, no differences in thickness and permeability for calcium could be established between cuticles of leaves grown on trees under the two types of hail nets or uncovered trees. For all evaluated parameters, significant differences were detected between the two cultivars examined. In both cultivars, leaf wax synthesis followed a characteristic curve, increasing from the first to the second evaluation, and then decreasing continuously without affecting cuticular penetration of calcium. Overall, our results show that a reduction of the hail nets by 6-10% in both light and humidity was insufficient to influence the surface properties of apple leaves and permeability of cuticles. This may suggest that pest management strategies, i.e. formulation of agrochemicals, their application and dose, do not need to be adapted when used under hail nets. Overall, the present results indicate that the microclimatic changes brought about by colored hail nets are sufficient to enhance the vegetative growth and induce the 'shade avoidance syndrome', but do not appear to affect the leaf cuticular properties.
Technological innovations appear under-utilised in many fruit tree crops, whereas viticulture, ci... more Technological innovations appear under-utilised in many fruit tree crops, whereas viticulture, citriculture and vegetable crops have largely automated planting, pruning, thinning and harvesting and integrated GPS and/or GIS in their cultivation practises. As a consequence of the trend from pedestrian to tall orchards, innovation and technology is required to overcome shading, particularly in the lower part of the tree canopy. Types, properties and prices are presented of reflective ground covers (textile, aluminium and paper) as well as organic alternatives (lime, straw) as well as titanium dioxide and biodegradable white line marker paint with additives. To combat sunburn, kaolin, carnauba-wax and other products are available, which can be combined with evaporative cooling. Mechanisation includes new machinery for mechanical thinning, pruning and harvesting to save labour. An autonomous prime mover (APM) is being developed for camera systems for assessment of flowering intensity, alternate bearing, fruit set, June drop, leaf nutrient status, pest and disease control and yield estimation/prediction. The two approaches for better light utilisation in row systems include reducing the spacing of every row from the current 14 feet (4.3 m) to 10-12 feet (3.0 to 2.6 m) or maintaining the spacing of a centre row at 14 feet (4.3 m) or ease of access, but narrower row spacing either side to less than 10 feet (3.0 m) The OTR (over the tree rows) developed by Washington State University and two commercial European multi-row sprayers are presented and new harvesting techniques with pre-sorting in the orchard.
Xylem flux or transpiration was measured in situ using the heat balance method on eight 4-year-ol... more Xylem flux or transpiration was measured in situ using the heat balance method on eight 4-year-old 'Braeburn' apple trees (4.9 m 2 leaf area) during summer 1999 at Klein-Altendorf experimental station near Bonn, Germany. The apple trees consumed from 70 ml of water per night per tree on cool summer nights to 180 ml water on warm summer nights. During the day, the apple trees transpired 1.7 litres per tree on cool, cloudy days and 4.8 litres on warm, sunny summer days. The midday depression in transpiration was more pronounced on sunny than on cloudy, cool days. The daily water consumption of the apple trees ranged from 1.8 to 5 litres water per tree, which was equivalent to 0.4-1 litres per day per m 2 leaf area. The best correlation was found between water consumption of the apple trees and water vapour deficit and, to a lesser extent, global radiation. These evaporation data now contribute to the weather fax and online service by the German National Meteorological Service (dwd), which supports growers in their decision making for irrigation based on meteorological data from dwd and evaporation values for fruit trees.
Measures for (a) improving the intensity of red colouration, and (b) increasing the proportion of... more Measures for (a) improving the intensity of red colouration, and (b) increasing the proportion of red peel on otherwise shaded parts of the fruit are reviewed with the aim of assessing their potential to meet consumer and market demands, produce healthier fruit and improve economic returns to the producer of bi-coloured apple and other fruits in the light of often unknown or under-estimated adverse side-effects of existing and new compounds mostly in the US in 2014; hence the underlying regulatory mechanisms of colour formation and inhibition in apple fruit are explained.Foliar fertilisers, used to enhance fruit colouration, so far had a limited effect principally in the order of 3–5 % better coloured fruit for most monophosphates—only ‘Seniphos’ (with 4 % CaO) consistently increased the proportion of well-coloured fruit by up to 8 %. Kaolin, a white particle film, appeared an unsuitable measure for improving fruit colouration at 50°N when sprayed onto the fruit, while it can significantly reduce sunburn at lower latitudes.Undesired side-effects such as lack of colouration can originate from misuse such as late application of excessive doses of 6-BA formulations, as otherwise properly used for thinning, or the gibberellin antagonist ProhexadionCalcium for shoot growth regulation. The mode of action is explained of colour promoting agents like methionin/phenylalanine (‘Sunred’), methyl jasmonate (‘Blush’), ethylene (‘Motivate’), aminoethoxvinylglycine (AVG, ‘Retain’) and abscisic acid (ABA, ‘ProTone’) although presently without registration in Europe.Light reflectors such as woven PE/PVP, aluminium-coated plastics, industrial-grade paper, straw, lime, kaolin, titanium oxide and lime-based compounds as mulch in the alleyways at least 4 weeks prior to anticipated harvest have been successfully used to enhance fruit colouration. They can particularly enhance the desired red colouration on the otherwise shaded green, (inner and lower) sides of the fruit. Colour improvements in the order of 8–10 % make reflective mulches particularly Extenday type PVP/PE/aluminium foils economically viable, particularly if used more than once a year. Light reflectors are more effective in years of poor colouration and in late ripening varieties, as intended; countryside concerns have to be considered.Cultivation measures at 50°N such as winter and summer as well as root pruning are the first steps to improve fruit (red) colouration by improving light penetration into the tree canopy and to the fruits, followed by light reflectors, ‘Seniphos’ like monophosphates, other fruit colour enhancing chemicals and evaporative cooling using overhead sprinklers at times of low humidity and little radiation (evening) and choice of lighter hail net (white or grey), hillsides (rather than valleys) and change to a variety with better colour. In any case, the greater content of anthocyanins in red apples provides an additional health benefit for the consumer without extra charge.
This work describes a new, computerised vision-based model to estimate the diameter and number of... more This work describes a new, computerised vision-based model to estimate the diameter and number of apple fruit on a tree and hence its yield autonomously under natural weather conditions in a fruit orchard. A charge-coupled device (CCD) camera acquired images of cvs ‘Golden Delicious’ and ‘Jonagold’ apple (Malus domestica L. Borkh.) trees seven times in the vegetation period, i.e. every two weeks from June to September 2007 for modelling the tree volume, fruit diameter and yield at harvest time. Images were processed off-line using image analysis for fruit colour, shape and texture. The fruit detection algorithm was successfully tested on trees bearing from 15 to 42 apple fruits and missed or mis-classified 1 to 3 apple fruits per tree. Fruit detection was sufficiently accurate with an 89 % rate and an overall error rate of 2.2 %. Fruit diameter was underestimated at the beginning of fruit growth in June, but the data corresponded closely (R2 = 0.96) with orchard measurements from Ju...
Apple leaf photosynthesis, measured by porometry, remained large at 814 µmol CO 2 m −2 s −1 and ... more Apple leaf photosynthesis, measured by porometry, remained large at 814 µmol CO 2 m −2 s −1 and was not limited by stomatal function after the commercial harvest date. The autumnal reduction both in photosynthesis and in vivo RUBISCO activity was less pronounced in ...
The objective of the study was to determine the carbon footprint for four farming and marketing s... more The objective of the study was to determine the carbon footprint for four farming and marketing systems, using primary data obtained on the farms for autumn pumpkin as an example and model crop. Area for the crop cultivation and weight, i.e. kilogram of saleable product, for the marketing phase were employed as the two functional units with system boundaries from
A higher frequency of hail storms, possibly due to climate change, has led to increased installat... more A higher frequency of hail storms, possibly due to climate change, has led to increased installation of hail nets worldwide. The objective of the present work was to investigate potential effects of the microclimate under these hail nets on micromorphological characteristics of the leaves and adaxial leaf cuticles. Leaves of apple cultivars 'Pinova' and 'Fuji' grown on trees under white (highly translucent) or red-black (low transmittance) hail nets or on uncovered (control) trees were evaluated in June, August, September and October. The microclimate under the colored hail nets had no impact on leaf micromorphology, amount of cuticular wax, or leaf thickness. Similarly, no differences in thickness and permeability for calcium could be established between cuticles of leaves grown on trees under the two types of hail nets or uncovered trees. For all evaluated parameters, significant differences were detected between the two cultivars examined. In both cultivars, leaf wax synthesis followed a characteristic curve, increasing from the first to the second evaluation, and then decreasing continuously without affecting cuticular penetration of calcium. Overall, our results show that a reduction of the hail nets by 6-10% in both light and humidity was insufficient to influence the surface properties of apple leaves and permeability of cuticles. This may suggest that pest management strategies, i.e. formulation of agrochemicals, their application and dose, do not need to be adapted when used under hail nets. Overall, the present results indicate that the microclimatic changes brought about by colored hail nets are sufficient to enhance the vegetative growth and induce the 'shade avoidance syndrome', but do not appear to affect the leaf cuticular properties.
Technological innovations appear under-utilised in many fruit tree crops, whereas viticulture, ci... more Technological innovations appear under-utilised in many fruit tree crops, whereas viticulture, citriculture and vegetable crops have largely automated planting, pruning, thinning and harvesting and integrated GPS and/or GIS in their cultivation practises. As a consequence of the trend from pedestrian to tall orchards, innovation and technology is required to overcome shading, particularly in the lower part of the tree canopy. Types, properties and prices are presented of reflective ground covers (textile, aluminium and paper) as well as organic alternatives (lime, straw) as well as titanium dioxide and biodegradable white line marker paint with additives. To combat sunburn, kaolin, carnauba-wax and other products are available, which can be combined with evaporative cooling. Mechanisation includes new machinery for mechanical thinning, pruning and harvesting to save labour. An autonomous prime mover (APM) is being developed for camera systems for assessment of flowering intensity, alternate bearing, fruit set, June drop, leaf nutrient status, pest and disease control and yield estimation/prediction. The two approaches for better light utilisation in row systems include reducing the spacing of every row from the current 14 feet (4.3 m) to 10-12 feet (3.0 to 2.6 m) or maintaining the spacing of a centre row at 14 feet (4.3 m) or ease of access, but narrower row spacing either side to less than 10 feet (3.0 m) The OTR (over the tree rows) developed by Washington State University and two commercial European multi-row sprayers are presented and new harvesting techniques with pre-sorting in the orchard.
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Papers by Michael Blanke