Two field experimental trials were carried out in central Italy, in 2005 and 2006, on biomass sorghum [Sorghum bicolor (L.) Moench] in order to assess weed control efficacy and selectivity to the crop for some herbicides. These were used in pre or post-emergence applications at different doses and in different mixtures. All herbicides showed a good selectivity to the crop, although, post-emergence treatments showed higher transitory phytotoxicity effects than pre-emergence treatments, especially when high temperature occurred after treatments, decreasing the selectivity of leaf herbicides (i.e. MCPA, 2,4D, bromoxynil and dicamba). Considering pre-emergence applications, terbuthylazine alone against broadleaves or in mixtures with propachlor and at low dose with s-metolachlor against mixed infestations (grasses + broadleaves), seemed to be the best options to obtain a good selectivity to the crop and a high weed control. Aclonifen and propachlor alone should be used with prudence due to unsatisfactory efficacy against A. retroflexus and P. oleracea respectively. Considering post-emergence applications, all treatments gave quite similar results in term of weed control, although, the mixture of terbuthylazine + bromoxynil seemed to be advisable, especially with high infestation of P. oleracea. Sorghum biomass showed not significant differences between herbicides treatments, although, biomass values seemed to be more related to herbicide selectivity than to herbicides efficacy, especially in the cases of scarce competitiveness of weed flora.
Chemical weed control in biomass sorghum [Sorghum bicolor (L.) Moench].
PANNACCI, Euro;
2010
Abstract
Two field experimental trials were carried out in central Italy, in 2005 and 2006, on biomass sorghum [Sorghum bicolor (L.) Moench] in order to assess weed control efficacy and selectivity to the crop for some herbicides. These were used in pre or post-emergence applications at different doses and in different mixtures. All herbicides showed a good selectivity to the crop, although, post-emergence treatments showed higher transitory phytotoxicity effects than pre-emergence treatments, especially when high temperature occurred after treatments, decreasing the selectivity of leaf herbicides (i.e. MCPA, 2,4D, bromoxynil and dicamba). Considering pre-emergence applications, terbuthylazine alone against broadleaves or in mixtures with propachlor and at low dose with s-metolachlor against mixed infestations (grasses + broadleaves), seemed to be the best options to obtain a good selectivity to the crop and a high weed control. Aclonifen and propachlor alone should be used with prudence due to unsatisfactory efficacy against A. retroflexus and P. oleracea respectively. Considering post-emergence applications, all treatments gave quite similar results in term of weed control, although, the mixture of terbuthylazine + bromoxynil seemed to be advisable, especially with high infestation of P. oleracea. Sorghum biomass showed not significant differences between herbicides treatments, although, biomass values seemed to be more related to herbicide selectivity than to herbicides efficacy, especially in the cases of scarce competitiveness of weed flora.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
