Natalia Georgieva1*, Ivelina Nikolova1, Yordanka NAYDENOVA2
1Department of Technology and ecology of forage crops, Institute of Forage Crops, Pleven, BULGARIA
2Department of biochemistry, Institute of Forage Crops, Pleven, BULGARIA
Corresponding author: e–mail: email@example.com
Abstract. The possibility for weed control in noncropped areas (stubbles) by using an organic product with herbicidal effect (Segador), alone and combined with low dose of synthetic herbicide (Roundup, 360 g/L glyphosate), was investigated. The individual application of Segador at a dose of 18 l/ha suppressed completely the annual grassy weeds and also showed a very good effect against broadleaf weeds and perennial grassy weeds (85–95 % efficacy), therefore could be recommended for organic farming. The combined application of Segador with Roundup at different doses significantly increased the efficacy of the herbicidal mixture. Its application depended on the predominant weed species in the cultivated area. The combination of Segador and Roundup, each one at a dose of 6 l/ha, provided good control of annual weeds and Sorghum halepense, but a certain resistance showed some perennial broadleaf species (Convolvulus arvensis, Rumex crispus and Cynodon dactylon) as the efficacy was in the limits 75–97 %. Increasing the dose of Segador up to 12 L/ha in combination with Roundup 6 L/ha suppressed Rumex crispus and Cynodon dactylon and increased the efficiency in Convolvulus arvensis to 95 %. Full control of annual and perennial weeds, provided the organic product Segador 18 L/ha + herbicide Roundup 6 L/ha, as the effect of the mixture was equalized with that of Roundup at a dose of 12 L/ha. The low dose of application of Roundup in combination with different doses of Segador minimized the use of synthetic herbicide and is recommended for conventional production.
Keyword: bioherbicide, weed control, efficacy, noncropped areas.