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Influence of term of winter rapeseed (Brassica napus) desiccation on yield and seed quality
Rajtmajer, Stanislav ; Bečka, David (advisor) ; Petr, Petr (referee)
Rapeseed is the world's third most important oil plant (the second seminal). It is the most cultivation and most important oil plant in Czech Republic. Winter rapeseed reaches about 85% of the harvest area of oilseeds in the country. The desiccation of oilseed crop is sphere of agricultural engineering, which is still worth discussing. The main problems are how to use the product, what dose and which dates to choose to desiccate. The results of this thesis could help to partially clarify this complex issue.
The aim of the thesis is to observe the effect of different terms oilseed rape desiccation by glyphosate on yield and seed quality.
Small-plot experiments to investigate the influence of the term desiccation of winter rapeseed were established in the years 2013/2014 and 2014/2015 on the lands of the experimental station of the Czech Agricultural University, Faculty of Agronomy Food and Natural Resources at the Červený Újezd.
In the first experimental year 2013/2014 was founded five variants in three replications (including undesiccated control). In the year 2014/2015 was founded seven variants in four replicates (including undesiccated controls). In the first experimental year was the first term desiccation 16. 6. 2014, the second year 8. 6. 2015. Subsequent periods of desiccation were a week apart.
The variety of winter rapeseed used for the experiments was a hybrid variety Rohan. The desiccating agent was used Dominator active substance glyphosate. The dose of
4 l / ha + 200 l H2O.
For all samples, both experimental, years yield was determined, the weight of a thousand seeds and oiliness. For desiccated variants were carried out pre-harvest analysis for the determination of solids in pods. Further, all harvested samples taken for laboratory germination test (Determination of germination) ISTA according to the methodology. The results of the experiment sprouting were statistically analyzed using ANOVA analysis of variance. Differences between mean values were evaluated by Tukey test, the computer program SAS at a significance level of p = 0.05.
Effect of desiccation term influences of winter oilseed rape seed quality in terms of weight and thousands of seeds in terms of oil content. Too early desiccation (46 to 39 days before harvest) HTS reduced by 7-17% and the oil content of 2-4% of the overall average. Oiliness of the observed characters minimum interference term desiccation. Desiccation in the optimum date (17 days before harvest) increased oiliness of 1-6%.
Influence term desiccation oilseed rape also greatly influences seed yield.
Too early desiccation (46 to 39 days before harvest) reduced the yield by 11-14%. Undesiccated control in both years achieved the highest yields, increase yield by 5-12%. Desiccation in the optimum date (17 days before harvest) increased the yield of attempts by 5-6%.
The term desiccation of winter rapeseed, also significantly affects the vitality of seeds, where very reduces energy germinating seedlings in the first days. The term desiccation, however, does not affect overall seed germination. Too early desiccation (46 to 39 days before harvest) EK2 decreased by 12-40%, EK3 decreased by 4-24%, 3-4% EK4 and extended MGT of 7-15%. In the first experimental year was the most vital option undesiccated control (EK2 = 50.4% = 91.3% EK3, EK4 = 97.9%). In the second experimental year was the most vital seeds of the optimal term desiccation, (Sixth term, 17 days before harvest) = 68.9% EK2, EK3 = 98.2%, EK4 = 100%. Seed samples of 2014/15 had a higher overall vitality of seeds, than samples from 2013/14, the overall vitality is probably worse given year old and transsilaged seed.
The results of the two-year experiment that term desiccation affects the quality of seeds, the yield of seeds and vitality of seeds. Pre-analysis was determined optimum solids content in siliques desiccated samples to values of 40-50%. Like most technology seems to desiccation in the optimum date (17 days before harvest) and agro technology without desiccated vegetation. As the least appropriate technology seems very early desiccation (46 to 30 days before harvest).
The first scientific hypothesis: Premature desiccation reduces seed yield, oil content and HTS. Yes, the hypothesis was confirmed.
The second scientific hypothesis: Desiccation made in the correct term do not affect the quality of the seeds (oiliness and HTS). Yes, the hypothesis was confirmed.
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