Wilfried Schnitzler - Academia.edu (original) (raw)

Papers by Wilfried Schnitzler

Scientia horticulturae, 2004

... All plants of the same replication were placed on one ebb-flood table supplied with the same ... more ... All plants of the same replication were placed on one ebb-flood table supplied with the same nutrient solution for 20 min twice a day. A flood-high-level of 2 cm was achieved. ... The data were analyzed by Tukey test (α=0.05) according to Cochran and Cox (1992). ...

Zeitschrift für Angewandte Entomologie, 1969

Noch vor einigen Jahren glaubte man mit chlorierten Kohlenwasserstoff en der Kohlfliege, Phorbia ... more Noch vor einigen Jahren glaubte man mit chlorierten Kohlenwasserstoff en der Kohlfliege, Phorbia brassicae Bouchk, Herr zu werden. Die lange Wirksamkeit dieser Mittel war fur die Bekampfung gunstig. Bald aber erwiesen ' Auazug aua cincr L>isacrr.irion. Uic u i i g c k u r z t c I-nssung wird .~u i 'Xunbch ~0111 Vcrf. zugcschickr.

Zeitschrift für Angewandte Entomologie, 1969

New Journal of Physics, 2008

We describe the construction and operation of a segmented linear Paul trap, fabricated in printed... more We describe the construction and operation of a segmented linear Paul trap, fabricated in printed-circuit-board technology with an electrode segment width of 500 µm. We prove the applicability of this technology to reliable ion trapping and report the observation of Doppler cooled ion crystals of 40 Ca + with this kind of traps. Measured trap frequencies agree with numerical simulations at the level of a few percent from which we infer a high fabrication accuracy of the segmented trap. To demonstrate its usefulness and versatility for trapped ion experiments we study the fast transport of a single ion. Our experimental results show a success rate of 99.0(1) % for a transport distance of 2 × 2 mm in a round-trip time of T = 20 µs, which corresponds to 4 axial oscillations only. We theoretically and experimentally investigate the excitation of oscillations caused by fast ion transports with error-function voltage ramps: For a slightly slower transport (a round-trip shuttle within T = 30 µs) we observe nonadiabatic motional excitation of 0.89(15) meV.

Journal of the Science of Food and Agriculture, 2000

Scientia Horticulturae, 2004

Several experiments were conducted with the objective to find suitable alternatives for peat subs... more Several experiments were conducted with the objective to find suitable alternatives for peat substrates. Physical properties of wood fiber substrates in comparison to other organic substrates were examined. Volume weight, total pore space, pore size distribution, available water, container and air capacity, saturated hydraulic conductivity and volume loss of these substrates were determined. Wood fiber substrates showed a similar volume weight and total pore space as peat substrates, but lower water retention. Particularly the drainage performance of wood substrates results in a quick drainage of surplus water. An increase of volume weight caused a decrease of total pore space, air content and saturated hydraulic conductivity and an increase in water retention. Evaluation of these parameters under container conditions is critical since they are directly related to irrigation and therefore to plant growth. A compression of wood fiber substrates in the pots is recommended to minimize substrate loss. An increase of compression levels reduced the volume loss to almost 0 vol.%. The effect of wood fiber substrates and their volume weight on plant growth will be reported in a second paper.

Scientia Horticulturae, 2004

The influence of wood fiber substrates (WFS) and their volume weights (VW) on the growth of tomat... more The influence of wood fiber substrates (WFS) and their volume weights (VW) on the growth of tomato transplants (Lycopersicon lycopersicum (L.) Karst. ex Farw.) were examined. No significant differences were observed for the absolute and relative growth rate of tomato transplants cultivated in WFS as compared to white peat (WP). Particularly in WFS plants showed a well developed root system. When the tomato transplants were cultivated in spring increases of VW led to a reduction of root growth, but no significant differences were observed for other plant parameters. In summer differences between weakly and strongly compacted substrate treatments for fresh mass of leaf and stem for both WFS were found. The coarse WFS also showed a significant difference in leaf area for these two treatments. Weakly compressed substrate had a faster decrease of matric potential in summer.

New Medit

According to the latest estimate of the United Nations, the World's urban population is expec... more According to the latest estimate of the United Nations, the World's urban population is expected to increase from 2.76 billion in 1995 to 5.34 billion in the year 2025 at which time more then half (2.72 billion) will reside in Asian cities. Many cities are expected to boom in the near future or are already booming besetting them with nearly insurmountable problems such as employment for often fairly uneducated migrants from rural areas, proper disposal of an abundance of refuse from households, commerce and industry by safe means and sufficient supply of cheap but nutritious food rich in vitamins and minerals to feed the population of these expanding urban centers. Through analysis of the economic, sociological, and anthropological situation of urban and periurban communities and small and medium-sized farm enterprises (SMEs) in these cities the different factors and constraints affecting and limiting the potential for vegetable production by SMEs should be evaluated and priorit...

Periurban agricultural activities are presented using the example of vegetable production in the ... more Periurban agricultural activities are presented using the example of vegetable production in the city of Cagayan de Oro, Philippines. Vegetable production's impact on food security, and the business opportunities it creates, are examined. Issues that still need to be considered to make periurban agriculture a successful economic, ecological, and social tool for cities are then outlined.

puvep.xu.edu.ph

One hundred institutional users of fresh vegetables in Cagayan de Oro City, Philippines, were sur... more One hundred institutional users of fresh vegetables in Cagayan de Oro City, Philippines, were surveyed to determine their purchasing patterns. Ten (10) hospitals, twenty (20) schools, fourteen (14) canteens, five (5) government and private institutions each, twenty six (26 ) restaurants and twenty (20) hotels were included in the survey. Seventy percent (70%) of the institutions bought vegetables on a daily basis. These were mostly (67%) bought from Cogon market while another fifteen percent (15%) bought from Carmen market bringing to eighty two percent (82%) the number of institutions sourcing their vegetable requirements mainly from the two wet markets in the city. Only thirteen percent (13%) of the institutions buy from supermarkets and this is only some of the time.

Journal of Applied Botany and Food Quality, 2004

ABSTRACT

Acta Horticulturae, 2006

... 357 Proc. VIIIth IS on Protected Cultivation in Mild Winter Climates Eds.: A. Hanafi and WH S... more ... 357 Proc. VIIIth IS on Protected Cultivation in Mild Winter Climates Eds.: A. Hanafi and WH Schnitzler Acta Hort. 747, ISHS 2007 ... The UV lamp was a high-pressure metal-halide gas lamp (400 W, MHL400/E40, BLV Licht) emitting UV-B at >294 nm (Heuberger et al., 2004). ...

Journal of Agricultural and Food Chemistry, Jan 25, 2006

Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with... more Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with salinity, inner quality characterized by taste and health-promoting compounds can be improved. For a detailed description of this relationship, the influence of three different salt levels [electrical conductivity (EC) 3, 6.5, and 10] in hydroponically grown tomatoes was investigated. Rising salinity levels in the nutrient solution significantly increased vitamin C, lycopene, and -carotene in fresh fruits up to 35%. The phenol concentration was tendentiously enhanced, and the antioxidative capacity of phenols and carotenoids increased on a fresh weight basis. Additionally, the higher EC values caused an increase of total soluble solids and organic acids, parameters determining the taste of tomatoes. Total fruit yield, single fruit weight, and firmness significantly decreased with rising EC levels. Regression analyses revealed significant correlations between the EC level and the dependent variables single fruit weight, total soluble solids, titrable acids, lycopene, and antioxidative capacities of carotenoids and phenols, whereas vitamin C and phenols correlated best with truss number, and -carotene correlated best with temperature. Only pressure firmness showed no correlation with any of the measured parameters. As all desirable characteristics in the freshly produced tomato increased when exposed to salinity, salinity itself constitutes an alternative method of quality improvement. Moreover, it can compensate for the loss of yield by the higher inner quality due to changing demands by the market and the consumer. This investigation is to our knowledge the first comprehensive overview regarding parameters of outer quality (yield and firmness), taste (total soluble solids and acids), nutritional value (vitamin C, carotenoids, and phenolics), as well as antioxidative capacity in tomatoes grown under saline conditions.

The gram-positive bacterium Bacillus subtilis is known to positively influence plant growth, vita... more The gram-positive bacterium Bacillus subtilis is known to positively influence plant growth, vitality, and the ability of the plant to cope with pathogens often re- sulting in higher yield. These beneficial effects are documented in field crops, where it has been ascribed to abiotic stress release. However, little is known about the mechanism by which B. subtilis interacts with the

Scientia horticulturae, 2004

... All plants of the same replication were placed on one ebb-flood table supplied with the same ... more ... All plants of the same replication were placed on one ebb-flood table supplied with the same nutrient solution for 20 min twice a day. A flood-high-level of 2 cm was achieved. ... The data were analyzed by Tukey test (α=0.05) according to Cochran and Cox (1992). ...

Zeitschrift für Angewandte Entomologie, 1969

Noch vor einigen Jahren glaubte man mit chlorierten Kohlenwasserstoff en der Kohlfliege, Phorbia ... more Noch vor einigen Jahren glaubte man mit chlorierten Kohlenwasserstoff en der Kohlfliege, Phorbia brassicae Bouchk, Herr zu werden. Die lange Wirksamkeit dieser Mittel war fur die Bekampfung gunstig. Bald aber erwiesen ' Auazug aua cincr L>isacrr.irion. Uic u i i g c k u r z t c I-nssung wird .~u i 'Xunbch ~0111 Vcrf. zugcschickr.

Zeitschrift für Angewandte Entomologie, 1969

New Journal of Physics, 2008

We describe the construction and operation of a segmented linear Paul trap, fabricated in printed... more We describe the construction and operation of a segmented linear Paul trap, fabricated in printed-circuit-board technology with an electrode segment width of 500 µm. We prove the applicability of this technology to reliable ion trapping and report the observation of Doppler cooled ion crystals of 40 Ca + with this kind of traps. Measured trap frequencies agree with numerical simulations at the level of a few percent from which we infer a high fabrication accuracy of the segmented trap. To demonstrate its usefulness and versatility for trapped ion experiments we study the fast transport of a single ion. Our experimental results show a success rate of 99.0(1) % for a transport distance of 2 × 2 mm in a round-trip time of T = 20 µs, which corresponds to 4 axial oscillations only. We theoretically and experimentally investigate the excitation of oscillations caused by fast ion transports with error-function voltage ramps: For a slightly slower transport (a round-trip shuttle within T = 30 µs) we observe nonadiabatic motional excitation of 0.89(15) meV.

Journal of the Science of Food and Agriculture, 2000

Scientia Horticulturae, 2004

Several experiments were conducted with the objective to find suitable alternatives for peat subs... more Several experiments were conducted with the objective to find suitable alternatives for peat substrates. Physical properties of wood fiber substrates in comparison to other organic substrates were examined. Volume weight, total pore space, pore size distribution, available water, container and air capacity, saturated hydraulic conductivity and volume loss of these substrates were determined. Wood fiber substrates showed a similar volume weight and total pore space as peat substrates, but lower water retention. Particularly the drainage performance of wood substrates results in a quick drainage of surplus water. An increase of volume weight caused a decrease of total pore space, air content and saturated hydraulic conductivity and an increase in water retention. Evaluation of these parameters under container conditions is critical since they are directly related to irrigation and therefore to plant growth. A compression of wood fiber substrates in the pots is recommended to minimize substrate loss. An increase of compression levels reduced the volume loss to almost 0 vol.%. The effect of wood fiber substrates and their volume weight on plant growth will be reported in a second paper.

Scientia Horticulturae, 2004

The influence of wood fiber substrates (WFS) and their volume weights (VW) on the growth of tomat... more The influence of wood fiber substrates (WFS) and their volume weights (VW) on the growth of tomato transplants (Lycopersicon lycopersicum (L.) Karst. ex Farw.) were examined. No significant differences were observed for the absolute and relative growth rate of tomato transplants cultivated in WFS as compared to white peat (WP). Particularly in WFS plants showed a well developed root system. When the tomato transplants were cultivated in spring increases of VW led to a reduction of root growth, but no significant differences were observed for other plant parameters. In summer differences between weakly and strongly compacted substrate treatments for fresh mass of leaf and stem for both WFS were found. The coarse WFS also showed a significant difference in leaf area for these two treatments. Weakly compressed substrate had a faster decrease of matric potential in summer.

New Medit

According to the latest estimate of the United Nations, the World's urban population is expec... more According to the latest estimate of the United Nations, the World's urban population is expected to increase from 2.76 billion in 1995 to 5.34 billion in the year 2025 at which time more then half (2.72 billion) will reside in Asian cities. Many cities are expected to boom in the near future or are already booming besetting them with nearly insurmountable problems such as employment for often fairly uneducated migrants from rural areas, proper disposal of an abundance of refuse from households, commerce and industry by safe means and sufficient supply of cheap but nutritious food rich in vitamins and minerals to feed the population of these expanding urban centers. Through analysis of the economic, sociological, and anthropological situation of urban and periurban communities and small and medium-sized farm enterprises (SMEs) in these cities the different factors and constraints affecting and limiting the potential for vegetable production by SMEs should be evaluated and priorit...

Periurban agricultural activities are presented using the example of vegetable production in the ... more Periurban agricultural activities are presented using the example of vegetable production in the city of Cagayan de Oro, Philippines. Vegetable production's impact on food security, and the business opportunities it creates, are examined. Issues that still need to be considered to make periurban agriculture a successful economic, ecological, and social tool for cities are then outlined.

puvep.xu.edu.ph

One hundred institutional users of fresh vegetables in Cagayan de Oro City, Philippines, were sur... more One hundred institutional users of fresh vegetables in Cagayan de Oro City, Philippines, were surveyed to determine their purchasing patterns. Ten (10) hospitals, twenty (20) schools, fourteen (14) canteens, five (5) government and private institutions each, twenty six (26 ) restaurants and twenty (20) hotels were included in the survey. Seventy percent (70%) of the institutions bought vegetables on a daily basis. These were mostly (67%) bought from Cogon market while another fifteen percent (15%) bought from Carmen market bringing to eighty two percent (82%) the number of institutions sourcing their vegetable requirements mainly from the two wet markets in the city. Only thirteen percent (13%) of the institutions buy from supermarkets and this is only some of the time.

Journal of Applied Botany and Food Quality, 2004

ABSTRACT

Acta Horticulturae, 2006

... 357 Proc. VIIIth IS on Protected Cultivation in Mild Winter Climates Eds.: A. Hanafi and WH S... more ... 357 Proc. VIIIth IS on Protected Cultivation in Mild Winter Climates Eds.: A. Hanafi and WH Schnitzler Acta Hort. 747, ISHS 2007 ... The UV lamp was a high-pressure metal-halide gas lamp (400 W, MHL400/E40, BLV Licht) emitting UV-B at >294 nm (Heuberger et al., 2004). ...

Journal of Agricultural and Food Chemistry, Jan 25, 2006

Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with... more Irrigation with saline water affects tomato fruit quality. While total fruit yield decreases with salinity, inner quality characterized by taste and health-promoting compounds can be improved. For a detailed description of this relationship, the influence of three different salt levels [electrical conductivity (EC) 3, 6.5, and 10] in hydroponically grown tomatoes was investigated. Rising salinity levels in the nutrient solution significantly increased vitamin C, lycopene, and -carotene in fresh fruits up to 35%. The phenol concentration was tendentiously enhanced, and the antioxidative capacity of phenols and carotenoids increased on a fresh weight basis. Additionally, the higher EC values caused an increase of total soluble solids and organic acids, parameters determining the taste of tomatoes. Total fruit yield, single fruit weight, and firmness significantly decreased with rising EC levels. Regression analyses revealed significant correlations between the EC level and the dependent variables single fruit weight, total soluble solids, titrable acids, lycopene, and antioxidative capacities of carotenoids and phenols, whereas vitamin C and phenols correlated best with truss number, and -carotene correlated best with temperature. Only pressure firmness showed no correlation with any of the measured parameters. As all desirable characteristics in the freshly produced tomato increased when exposed to salinity, salinity itself constitutes an alternative method of quality improvement. Moreover, it can compensate for the loss of yield by the higher inner quality due to changing demands by the market and the consumer. This investigation is to our knowledge the first comprehensive overview regarding parameters of outer quality (yield and firmness), taste (total soluble solids and acids), nutritional value (vitamin C, carotenoids, and phenolics), as well as antioxidative capacity in tomatoes grown under saline conditions.

The gram-positive bacterium Bacillus subtilis is known to positively influence plant growth, vita... more The gram-positive bacterium Bacillus subtilis is known to positively influence plant growth, vitality, and the ability of the plant to cope with pathogens often re- sulting in higher yield. These beneficial effects are documented in field crops, where it has been ascribed to abiotic stress release. However, little is known about the mechanism by which B. subtilis interacts with the