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Wageningen, Netherlands

Sreckov Z.,University of Novi Sad | Nastasic A.,Serbian Institute of Field and Vegetable Crops | Bocanski J.,University of Novi Sad | Djalovic I.,Serbian Institute of Field and Vegetable Crops | And 2 more authors.
Pakistan Journal of Botany | Year: 2011

One of the goals of this paper was to determine correlation between grain yield, like the most important agronomic trait, and traits of the plant and ear that are influencing on the grain yield, in two test-cross populations, which are formed by crossing progenies of NSU1 population after 17 cycles of phenotypic recurrent selection and two testers, 568/II NS and B73. At 568/II NS testcrosses, grain yield had the highest value of genotypic coefficient of correlations with kernel row number. In second studied population the highest value of coefficient of correlations also was found between grain yield and kernel row number, but that relation was negative. Path coefficient analysis provides more information among variables than do correlation coefficients. Because of that goal of this study also was founding the direct and indirect effects of morphological traits on grain yield. Desirable, high significant influence on grain yield, in path coefficient analysis, was found for ear height, in both studied populations. Plant height, in both testcross populations, kernel row number and oil content, at B73 testcrosses, has high significant undesirable effect on grain yield. Source

Bocanski J.,University of Novi Sad | Sreckov Z.,University of Novi Sad | Nastasic A.,Serbian Institute of Field and Vegetable Crops | Ivanovic M.,Serbian Institute of Field and Vegetable Crops | And 2 more authors.
Genetika | Year: 2010

Utilization of heterosis requires the study of combining abilities of potential parents. In view of this, the objective of this paper was to study combining abilities and determine the mode of inheritance and gene effects for the main agronomic character, grain yield, and its components, kernel row number and kernel number per row. Six inbred lines were used in the study, three of which originated in the U.S., while the other three were developed at the Institute of Field and Vegetable Crops in Novi Sad. Kernel row number was inherited by superdominance, partial dominance, complete dominance and intermediacy. The mode of inheritance of kernel number per row and grain yield was superdominance. Additive gene action had the greatest influence on the expression of kernel row number, while the other two traits were influenced the most by nonadditive gene. Source

Venus V.,University of Twente | Asare-Kyei D.K.,ACDI VOCA | Tijskens L.M.M.,WUR | Weir M.J.C.,University of Twente | And 6 more authors.
Computers and Electronics in Agriculture | Year: 2013

In an effort to better understand postharvest losses associated with low-cost tomato transport in West Africa we present a spatial-temporal simulation model that links the prevailing outside weather conditions, estimated using satellite meteorology, to the microclimate observed inside truck trailers (cryptoclimate) to determine the deterioration in tomato quality during transport. Tomatoes from Burkina Faso are transported under sub-optimal circumstances to important Ghanaian markets; during a number of these transports conditions for the tomato cargo inside trucks were measured while conditions outside the trucks were monitored by means of weather satellites. The presented tomato quality model analytically combines cryptoclimate, duration since harvest, and kinetic modelling to arrive at estimated firmness. Firmness of tomatoes in transport was monitored with a portable penetrometer in selected trucks, augmented with additional (acoustic firmness) data collected in a climate chamber. Half of these observations were used to calibrate a firmness loss model and the other half to validate the simulation results.Our results indicate that outside weather during transport can be reasonably well estimated using satellite meteorology. The model performance for the estimation of outside global radiation (Rg) and land-surface temperature (LST) were found to be satisfactory, with a RMSE=87.98Wm-2; bias=57.39Wm-2 and RMSE=2.95°C; bias=0.91°C, respectively. Results for the cryptoclimate estimation (conditions inside the trucks) for temperature, relative humidity, and light intensity were as follows: R2=0.77, RMSE=4.18°C (Tincargo); R2=0.84, RMSE=19.59% (RHincargo); and R2=0.9, RMSE=137.31lx (LIincargo). The postharvest loss model that relies on these estimates as its input explained on average 77% of the variance in observed tomatoes firmness, with total product losses ranging from 30% to 50% when integrated over the entire transportation period.With the accuracy of the model quantified and the causality of losses partially demonstrated, we argue that the simulation model can be useful as an economic resistor in transport optimization studies to investigate the cost-benefit of various measures to reduce postharvest losses. Such studies could help to illustrate what net gains can be expected if delays along the transportation route are reduced, cargo conditions are semi-controlled (e.g. pre-cooling treatment), or if a different transport schedule is adopted. The model may also be used to show the impact of different climate change scenarios on postharvest losses. © 2013 Elsevier B.V. Source

Bocanski J.,University of Novi Sad | Nastasic A.,Serbian Institute of Field and Vegetable Crops | Stanisavljevic D.,Serbian Institute of Field and Vegetable Crops | Sreckov Z.,University of Novi Sad | And 3 more authors.
Genetika | Year: 2011

Genetic markers, from morphological to molecular, in function with early Heterosis is a prerequisite for the successful commercial maize production. It does not appear in any cross of two inbred lines, and therefore, the determination of combining abilities of parental lines is essential. The most commonly used method for determining combining abilities is diallel analysis. Besides conventional methods for diallel analysis, a new biplot approach has been sugested. In this paper, we studied the combining ability for grain yield in a set of genotypes obtained by diallel crossing system of six inbred lines. Both, the Griffing's conventional method and the biplot approach have been used for diallel analysis Comparing the GCA values from biplot analysis and Griffing's method, similar results can be observed, with the exception of NS L 1051 and NS L 1000 whose ranks are interchanged. Biplot analysis enables the SCA estimation of parent inbred, and the highest SCA has inbred B73D. Biplot analysis also allows the estimation of the best crosses. Inbred B73D shows the best results when crossed with testers Mo17Ht, NS L 1051 and N152, inbred N152 combines best with testers NS L 1001 and NS L 1000, whereas the cross of inbred NS L 1051 with tester B73D results with the highest grain yield per plant in comparison with other testers. Source

Hensen A.,Energy Research Center of the Netherlands | Bleeker A.,Energy Research Center of the Netherlands | Erisman J.W.,Energy Research Center of the Netherlands | Syakila A.,WUR | And 4 more authors.
Journal of Integrative Environmental Sciences | Year: 2010

This article describes two different visualisation instruments that can be used for awareness raising and educational purposes: Nitrogenius and the N-visualisation tool. Both instruments aim to convey the complex interactions that occur in the nitrogen (N) cycle and the need for integrated measures when aiming to reduce Nrelated environmental problems such as eutrophication, acidification or global warming. Nitrogenius was developed in the year 2000. This four-player computer "game" focuses on the Dutch N problems caused by N2O, NH3 and NOx emissions as well as nitrate in surface and ground water. Underlying the glossy user interface is a set of comprehensive models and a database with potential measures that were considered to be feasible at the time. Since 2000, the model has been used for educational purposes annually at Wageningen University. About 150 MSc students played the game, with the aim to solve the N-related problems in the Netherlands. This article analyses these games, and presents the surprising correlation for the period 2000-2007 with the actual environmental trends in the Netherlands. The second tool is an N- visualisation tool that was developed in 2007. This tool provides both a historic overview of the nitrogen issue and demonstrates the effect of seven potential measures on the world wide N cycle. The effects of increased biomass use and intensification of agriculture are examples of included measures. The net effect on global warming, food availability and biodiversity are output parameters of this instrument. The calculations and assumptions underlying this tool are easily accessible through an open source spreadsheet. This tool was used in 2008 and 2009 at Wageningen University for educational purposes. The pros and cons of both games for awareness raising and educational purposes will be discussed. © 2010 Taylor & Francis. Source

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