Räni ja reavahe mõju rapsi saagikusele ja kvaliteedile

Keskkonnasäästliku põllumajanduse eesmärgiks on kasutada vähem sisendeid, mille tõttu tuleb otsida võimalusi, kuidas säilitada sama saagitase optimeerides sisendite osakaalu. Üheks võimaluseks on leida optimaalne reavahe rapsi kasvatuse jaoks. Teine võimalus on kasutada räni, millel on leitud positiivset mõju ka kliimamuutustest tingitud taimestressi leevendamisel. Bakalaureusetöö eesmärk oli uurida, kuidas mõjutab reavahede laiuse muutmine suvirapsi seemnesaagikust ning -kvaliteeti ning millist mõju omab räni suvirapsi seemnesaagikusele ja -kvaliteedile. Uurimustöö põhineb põldkatsel. Suvirapsi sort Majong külvati kolme erineva reavahega (12,5; 25; 37,5 cm) kolmes korduses. Räniga töötlemiseks kasutati lehepreparaati Optysil. Katselapid koristati teraviljakombainiga, hiljem saadeti kordustelt kogutud seemneproovid Scanola laborisse, kus analüüsiti seemnete kvaliteedi parameetreid. Seemnesaagikuse ja reavahede vahel oli tugev negatiivne seos (r= -0,9984). See tähendab, et reavahede laienedes suvirapsi saagikus langeb. Kõrgeim saak saadi 12,5 cm reavahes ning madalaim 37,5 cm reavahes. Räniga töötlemine tõstis saagikust laiemas reavahes, kuid tulemused ei olnud statistiliselt usutavad võrdluses kontrolliga. Reavahe mõju õlisisaldusele oli märgata ainult 37,5 cm reavahes. Räniga töötlemine mõjus õlisisaldusele positiivselt. Töö tulemused annavad hea indikatsiooni, et reavahe ja lehekaudse räniga on võimalik saaki mõjutada, kuid edasised katsed on vajalikud tulemuste kinnitamiseks.

Environmentally friendly farming needs to manage with less inputs, which means that solutions have to be sought to maintain the same yields with fewer inputs. One option would be to find the optimal spacing for oilseed rape cultivation. Another option is to use foliar silicon treatment that has been shown to have positive effect on the plants under stress caused by environment or climate. The aim of this thesis was to investigate the effects of varying row spacing and the impact of silicon treatment on spring oilseed rape seed yield and quality. The field experiment was conducted with spring oilseed rape variety Majong sown in three replicates with three different row spacings (12.5; 25; 37.5 cm). Fertilisation and plant protection were the same for all replications, but the sowing rate was reduced with increasing row spacing (100; 90; 80 germinating grains per square metre, respectively). Optysil was used for silicon treatment. The test plots were harvested with a combine harvester and the seed samples collected from the replicates were later sent to Scanola laboratory for chemical analysis. There was a strong negative correlation between seed yield and row spacing (r= -0.9984). This means that as the row spacing increases, the yield in spring rape decreases. The highest yield was obtained at 12.5 cm row spacing and the lowest yield was obtained at 37.5 cm row spacing. Silicon treatment increased yields at wider row spacings, but the results were not statistically significant when compared with the control. The effect on oil content was only noticeable in the 37.5 cm row spacing. The oil content of the seeds obtained at 12.5 cm and 25 cm row spacing was 41.6%, but at 37.5 cm row spacing it was 39.2%. Silicon spraying had a positive effect on oil content. The results give a good indication that row space optimization and silicon have effect on oilseed rape cultivation, but further experiments are needed to prove this.