Content of zinc and iron in common bean seeds (Phaseolus vulgaris L.) in different weed control methods

A field experiment was conducted in 2010-2012 on a private farm located in the village of Frankamionka in the administrative district (powiat) of Zamość, on brown soil with slightly acidic pH, and the average abundance of zinc and iron. The experiment was set up in a random split-plot design with four replications, with seven methods for controlling weed infestation: 1) no weeding control, 2) hand weeding control, 3) linuron (Afalon dyspersyjny 450 SC), 4) linuron + metribuzin (Afalon dyspersyjny 450 SC + Mistral 70 WG), 5) linuron + chlomazone (Harrier 295 ZC), 6) linuron + chlomazone + metribuzin (Harrier 295 ZC + Mistral 70 WG), 7) bentazon (Basagran 480 SL twice). The objective of the study was to determine the effect of weeding control methods on the content of iron and zinc in the seeds of cv. Jaś Karłowy common bean (Phaseolus vulgaris L.). The highest seed yield, on average 29.39 dt ha-1, was obtained on the plots where weeds were controlled by the application of the herbicides Harrier 295 ZC + Mistral 20 WG just after sowing. The lowest seed yield was harvested on unweeded plots – 6.77 dt ha-1 on average. Statistical analysis showed a significant effect of the weed control methods and the weather conditions in growing seasons on the content of iron and zinc in bean seeds. The lowest amount of zinc, an average of 36.11 mg kg-1, was found in beans from unweeded plots. The use of the herbicides Afalon dyspersyjny 450 SC + Mistral 70 WG, Harrier 295 ZC and Harrier 295 ZC + Mistral 70 WG significantly increased the zinc content compared to the un weeded control and manual weeding. The highest iron concentration, on average 75.12 mg kg-1, was observed in seeds from unweeded plots. Significantly less iron accumulated in beans from plots weeded manually and by application of the herbicides Harrier 295 ZC and Harrier 295 ZC + Mistral 70 WG.