Influence of herbicides and application timing on broadleaf weeds control in maize (Zea mays L.)

Mariyan Yanev, Anyo Mitkov, Nesho Neshev

Abstract: During 2018 and 2019 a field plot trial with maize (hybrid Blason Duo) was conducted. The study was situated on the experimental field of the Agricultural University of Plovdiv, Bulgaria. The trial was performed by the randomized block design in 4 replications. The florasulam-containing herbicide products Derby Super, Starane Gold and Kabadex Extra were under evaluation. The studied herbicide products were applied in two phenological stages of maize – BBCH 15 (3rd – 5th true leaf) and BBCH 18 (8th – 9th true leaf). The efficacy of the studied products by the 10-score visual scale of EWRS was reported. The selectivity by the 9-score scale of EWRS was also evaluated. The efficacy of the herbicide was higher after the application in BBCH 15 in comparison to that in BBCH 18. The highest herbicide efficacy against the weeds Chenopodium album L., Amaranthus retroflexus L., Xanthium strumarium L., Abutilon theophrasti Medik. and Solanum nigrum L. after the application of Kabadex Extra – 0.45 l ha-1 in BBCH 15, followed by Derby Super – 33 g ha-1 treated in the same stage was recorded. For the treatment with Kabadex Extra – 0.45 l ha-1 in BBCH 15 the studied parameters ear length, ear diameter, number of seeds per ear, absolute seed mass and grain yield were the highest. For all treatments accept for Starane Gold in BBCH 15, visual symptoms of phytotoxicity on the 7th day after application were recorded. The symptoms completely disappear on the 28th day after application.

Keywords: weeds, herbicides, efficacy, selectivity, yield

Date published: 2021-09-15