TY  - THES
T1  - Evaluation of the new cropping practices in sugar beet (Beta vulgaris L.) cultivation in the central black soil region of Russian Federation
A1  - Bezhin,Kostyantyn
Y1  - 2019/12/09
N2  - In recent years Russian sugar production has exceeded the country needs with a surplus of 500.000 tons. Sugar producers and traders are forced to start trading on the global markets. However, ineffective production, caused by low yields of sugar puts the price of Russian sugar 35 to 50 % higher than the leading sugar exporters.
Weeds belong to one of the main factors reducing sugar beet yield. Weeds that survive control operations may cause significant crop yield reductions. Rapid emergence and homogeneous crop stand are very important for competition with weeds. At the same time, the crop may be suppressed by selective herbicide application, if herbicides are applied during suboptimal weather conditions. This study evaluated glyphosate-tolerant sugar beet technology and seed priming for the possibility to increase the productivity of sugar beet cultivation.
A series of studies were carried out in different environments in Germany and in Russian Federation. The scope of the studies was dealing with: 
i)	comparison of the conventional weed control technology with technology, based on glyphosate applications;
ii)	a study of the crop weed interaction in German environment and in the environment of the Central black soil region of the Russian Federation;
iii)	tests of sugar beet seed priming for the speed of germination by means of growth chamber test, and for the speed of emergence in the soil seedbed, by means of greenhouse and field experiments.
The results of the conducted experiments are concentrated in three scientific articles that have been published in the international peer-reviewed journals:
The purpose of the first article was to analyse the weed control efficacy of weed control schemes with one, two and three applications of glyphosate and compare it with the conventional weed control technology. The results show that the application of glyphosate supplied significantly higher efficacy of weed control than conventional herbicides. In five out of 7 experiments single application of glyphosate gave the same weed control efficacy as two or three applications. No significant differences in weed control efficacy were observed between two different dosages of glyphosate – 900 and 1350 g a.e. ha-1. The variants treated with conventional herbicides and with two and three glyphosate applications showed no significant differences in white sugar yield. In one location, the variant with one application of glyphosate resulted in lower white sugar yield due to delayed application of herbicide, and longer time of crop and weed interference.
The aim of the second article was to study the yield loss caused by the competition with weeds in different environments. In the Russian locations Chenopodium album L. and Amaranthus retroflexus L. caused serious yield reduction already at low plant densities. White sugar yields harvested at Russian locations were approximately 45 % lower than in German locations. At Russian locations 50 % of the maximum weed population has caused more than 80 % yield reduction. Relative weed cover was the best predictor of the sugar beet yield loss.  Weed biomass and weed density gave less accurate predictions.
The third article was focused on testing of priming technology on the seed performance and crop establishment. In the controlled environment, primed seeds needed 10 days to reach full germination percentage of the seeds, for not primed seeds it took between 12 and 14 days. Primed seeds produced significantly larger area of plant foliage area and amount of dry biomass than non-rimed seeds. In uncontrolled environments, findings of previous experiments could not be confirmed. Priming did not influence the weed suppressive ability of the crop and the white sugar yield.
The general conclusion of this dissertation is that GT technology may help to improve the profitability of sugar beet cultivation for Russian growers by reducing the number of herbicide applications and increase weed control efficacy. Seed priming can give benefits for crop establishment, however only under specific environmental conditions.
KW  - Zuckerrübe
CY  - Hohenheim
PB  - Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim
AD  - Garbenstr. 15, 70593 Stuttgart
UR  - http://opus.uni-hohenheim.de/volltexte/2019/1678
ER  -