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The publication comprises a description of a test method for sugar beet harvesting devices and presents the field test results from 1984 to 2012. Quality parameters examined for harvesters were beet mass losses (both surface and sub-surface), root breakage, soil tare, and topping quality (accuracy and crown retention). The tests were held at Seligenstadt Estate near Würzburg/Germany on a test plot with loess soil. The introduction together with the chapter methods focuses on the test method which is constituted as an international standard of the International Institute of Sugar Beet Research (IIRB) dedicated to unifying the assessment of the working quality of harvest machines. The results from the last test held in 2012 are introduced in more detail outlining the working quality of the participating harvesters representing the state of technique. As a review targeted to reveal the trend of the last decades the test results from the beginning in 1984 are presented with a preceding paragraph on the progress and changes in the design and functions of the harvest machines in this time range.The test results outline a shift in the topping quality tending to a slighter topping of the beets to avoid mass losses due to excessive overtopping. The share of beets that are over-topped decreased in the last tests. Major mass losses over the entire time span originate from breakage of the root tips accounting for 2.7%, on the surface, and underground mass losses amount to 0.9%. Soil tare strongly depends on soil conditions (soil water content and soil type) having an average of 9.8% over test years. [ABSTRACT FROM AUTHOR]

In the past, chemical thinning dominated in fruit orchards. This paper for the special issue outlines alternatives to chemical thinning for crop load management (CLM) and its effect on fruit size, firmness, sugar, starch, and weight, indicating ripeness and fruit quality, yield, and alternate bearing. A total of 450 apple trees (Malus domestica Borkh., cv. 'Roter Boskoop'; six years old) on M9 rootstock were used at the Klein-Altendorf experimental station (50° N) of the University of Bonn, Germany. As the first alternatives, trees were mechanically blossom-thinned at the balloon stage (BBCH 59) with a rotor speed of 320 rpm or 380 rpm at 5 km/h tractor speed or were chemically thinned at the full bloom stage (BBCH 65) with ammonium thiosulfate (ATS), ethephon (ETH), and/or 6-benzyladenine (BA) at 10–12 mm fruit size (BBCH 71) after applying ATS/ETH. Flower clusters and/or cluster leaves (source) were manually removed to determine the optimum sink-source ratio to achieve different ratios of fruitlets (sink) relative to the leaves (source) at fruit set (BBCH 67–69). Un-thinned, adjacent trees served as the control. The majority of CLM methods improved fruit size and weight. Removing cluster leaves at fruit set increased fruit size and weight of the remaining fruit, which has not been observed before. The most effective treatment for fruit size and weight and return bloom was the 75% flower cluster and complete cluster leaf removal. Removal of more than 50% of flower clusters successfully improved return bloom, indicative of alternate bearing. The mechanical blossom thinning had a positive effect on fruit size and weight with a return bloom similar to that of removal of 50% flower clusters. [ABSTRACT FROM AUTHOR]

Plant-specific herbicide application requires sensor systems for plant recognition and differentiation. A literature review reveals a lack of sensor systems capable of recognizing small weeds in early stages of development (in the two- or four-leaf stage) and crop plants, of making spraying decisions in real time and, in addition, are that are inexpensive and ready for practical use in sprayers. The system described in this work is based on free cascadable and programmable true-color sensors for real-time recognition and identification of individual weed and crop plants. The application of this type of sensor is suitable for municipal areas and farmland with and without crops to perform the site-specific application of herbicides. Initially, databases with reflection properties of plants, natural and artificial backgrounds were created. Crop and weed plants should be recognized by the use of mathematical algorithms and decision models based on these data. They include the characteristic color spectrum, as well as the reflectance characteristics of unvegetated areas and areas with organic material. The CIE-Lab color-space was chosen for color matching because it contains information not only about coloration (a- and b-channel), but also about luminance (L-channel), thus increasing accuracy. Four different decision making algorithms based on different parameters are explained: (i) color similarity (DE); (ii) color similarity split in DL, Da and Db; (iii) a virtual channel 'd' and (iv) statistical distribution of the differences of reflection backgrounds and plants. Afterwards, the detection success of the recognition system is described. Furthermore, the minimum weed/plant coverage of the measuring spot was calculated by a mathematical model. Plants with a size of 1-5% of the spot can be recognized, and weeds in the two-leaf stage can be identified with a measuring spot size of 5 cm. By choosing a decision model previously, the detection quality can be increased. Depending on the characteristics of the background, different models are suitable. Finally, the results of field trials on municipal areas (with models of plants), winter wheat fields (with artificial plants) and grassland (with dock) are shown. In each experimental variant, objects and weeds could be recognized. [ABSTRACT FROM AUTHOR]

To realize site-specific and variable-rate application of agricultural pesticides, accurately metering and controlling the chemical injection rate is necessary. This study presents a prototype of a direct nozzle injection system (DNIS) by which chemical concentration transport lag was greatly reduced. In this system, a rapid-reacting solenoid valve (RRV) was utilized for injecting chemicals, driven by a pulse-width modulation (PWM) signal at 100 Hz, so with varying pulse width the chemical injection rate could be adjusted. Meanwhile, a closed-loop control strategy, proportional-integral-derivative (PID) method, was applied for metering and stabilizing the chemical injection rate. In order to measure chemical flow rates and input them into the controller as a feedback in real-time, a thermodynamic flowmeter that was independent of chemical viscosity was used. Laboratory tests were conducted to assess the performance of DNIS and PID control strategy. Due to the nonlinear input-output characteristics of the RRV, a two-phase PID control process obtained better effects as compared with single PID control strategy. Test results also indicated that the set-point chemical flow rate could be achieved within less than 4 s, and the output stability was improved compared to the case without control strategy. [ABSTRACT FROM AUTHOR]

Oxygen (O2) concentration inside the substrate is an important measurement for silage-research and-practical management. In the laboratory gas chromatography is commonly employed for O2 measurement. Among sensor-based techniques, accurate and reliable in situ measurement is rare because of high levels of carbon dioxide (CO2) generated by the introduction of O2 in the silage. The presented study focused on assessing three types of commercial O2 sensors, including Clark oxygen electrodes (COE), galvanic oxygen cell (GOC) sensors and the Dräger chip measurement system (DCMS). Laboratory cross calibration of O2 versus CO2 (each 0-15 vol.%) was made for the COE and the GOC sensors. All calibration results verified that O2 measurements for both sensors were insensitive to CO2. For the O2 in situ measurement in silage, all O2 sensors were first tested in two sealed barrels (diameter 35.7 cm; height: 60 cm) to monitor the O2 depletion with respect to the ensiling process (Test-A). The second test (Test-B) simulated the silage unloading process by recording the O2 penetration dynamics in three additional barrels, two covered by dry ice (0.6 kg or 1.2 kg of each) on the top surface and one without. Based on a general comparison of the experimental data, we conclude that each of these in situ sensor monitoring techniques for O2 concentration in silage exhibit individual advantages and limitations. [ABSTRACT FROM AUTHOR]

Oxygen (O₂) concentration inside the substrate is an important measurement for silage-research and-practical management. In the laboratory gas chromatography is commonly employed for O₂ measurement. Among sensor-based techniques, accurate and reliable in situ measurement is rare because of high levels of carbon dioxide (CO₂) generated by the introduction of O₂ in the silage. The presented study focused on assessing three types of commercial O₂ sensors, including Clark oxygen electrodes (COE), galvanic oxygen cell (GOC) sensors and the Dräger chip measurement system (DCMS). Laboratory cross calibration of O₂ versus CO₂ (each 0-15 vol.%) was made for the COE and the GOC sensors. All calibration results verified that O₂ measurements for both sensors were insensitive to CO₂. For the O₂ in situ measurement in silage, all O₂ sensors were first tested in two sealed barrels (diameter 35.7 cm; height: 60 cm) to monitor the O₂ depletion with respect to the ensiling process (Test-A). The second test (Test-B) simulated the silage unloading process by recording the O₂ penetration dynamics in three additional barrels, two covered by dry ice (0.6 kg or 1.2 kg of each) on the top surface and one without. Based on a general comparison of the experimental data, we conclude that each of these in situ sensor monitoring techniques for O₂ concentration in silage exhibit individual advantages and limitations.

Boar taint is a specific off-odour of boar meat products, known to be caused by at least three unpleasant odorants, with very low odour thresholds. Androstenone is a boar pheromone produced in the testes, whereas skatole and indole originate from the microbial breakdown of tryptophan in the intestinal tract. A new procedure, applying stable isotope dilution analysis (SIDA) and dynamic headspace-thermal desorption-gas chromatography/time-of-flight mass spectrometry (dynHS-TD-GC/TOFMS) for the simultaneous quantitation of these boar taint compounds in pig fat was elaborated and validated in this paper. The new method is characterised by a simple and solvent-free dynamic headspace sampling. The deuterated compounds d3-androstenone, d3-skatole and d6-indole were used as internal standards to eliminate matrix effects. The method validation performed revealed low limits of detection (LOD) and quantitation (LOQ) with high accuracy and precision, thus confirming the feasibility of the new dynHS-TD-GC/TOFMS approach for routine analysis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)