Identification of tolerance to metribuzin and imazethapyr herbicides in faba bean

Abstract

Weeds cause serious constraint to faba bean (Vicia faba L.) productivity. Broad weed control is hampered by the availability of postemergence herbicides to control them, as the current faba bean cultivars are highly susceptible to them. Therefore, the deployment of postemergence herbicide tolerance is desirable in faba bean. To address this, 130 accessions were screened for their response in mature plants under field conditions to the recommended dosage of two herbicides, metribuzin at 250 g a.i. ha −1 and imazethapyr at 75 g a.i. ha −1 at Marchouch and Terbol stations. The recorded herbicide damage score (HDS) varied from 1 (no visual damage) to 5 (full damage with death of more than 50% of plants) at both locations. Low but highly significant (p < .01) and positive correlation (+0.26) was obtained between the recorded HDS at both locations. Both herbicides significantly delayed flowering and maturity time occurrence, reduced plant height and grain yield, and increased number of branches. Reduction index (RI) correlated positively with HDS score at Terbol station in different seasons and at Marchouch in 2016-2017 seasons. Eleven tolerant accessions were identified and further evaluated to 1×, 1.5×, and 2× of recommended dose of both herbicides. The results indicated that the harmful effect of herbicides on grain yield reduction intensified from 13.4 to 27.2% and from −7.6 to 1.8% as the dose of metribuzin and imazethapyr increased respectively from 250 to 500 g a.i. ha −1 and from 75 to 150 g a.i. ha −1 . Tolerance to metribuzin and imazethapyr in eight faba bean accessions was confirmed with no significant reduction in grain yield.

Evaluation of performance and stability of new sources for tolerance to post-emergence herbicides in lentil (

“…Herbicide damage score was found to be associated with reduction indexes in the experiment conducted in 2017/18, which was a moderately rainy growing season. This indicates the efficiency of the HDS for screening for herbicide tolerance in lentils and aligns with the results obtained in faba bean (Abou-Khater et al 2021). However, this observation was not replicated during 2018/19 in our experiments; this is because of heavy rain during the winter season and abnormally high temperatures during pod set (April) and grain filling (May), which affected the growth habit of the plants.…”

Adaptability and Stability of Faba Bean (Vicia faba L.) Accessions under Diverse Environments and Herbicide Treatments

“…Thirty-six accessions were pure lines derived from single plant selections in three consecutive seasons which represent landraces from 21 countries and one cultivar Elisar (Flip 86-98FB) released in Lebanon was used as check (Table S1). Among them, 14 were tolerant or moderately tolerant to both the herbicides @ 250 g ai/ha metribuzin and 75 g ai/ha imazethapyr, six were tolerant to 250 g ai/ha metribuzin but sensitive to imazethapyr, and 16 were tolerant to 75 g ai/ha imazethapyr but sensitive to metribuzin ( [9], ICARDA, unpublished data). 7.…”

“…The remaining 19 accessions yielded more than the average grain yield as they were located on the right side of ATA; 6 of them were tolerant to both herbicides' treatments across environments. Among the accessions that yielded more than the average grain yield and are tolerant to both herbicides, FB2648 ( 14), IG12983 (35) and VF522 (9) were the most stable as they had the shortest projection to the ATA. Hence, based on Figure 4a,b, the metribuzin and imazethapyr tolerant accession IG12983 (35) was considered a superior genotype in terms of plant height and grain yield as it showed a good and stable performance for both traits across environments.…”

“…An integrated weed management that employs a variety of chemical and non-chemical methods is an effective way of minimizing the losses caused by weeds. The development of resistant cultivars to multiple herbicides with different modes of action [9][10][11] is still the most economical and environmentally friendly control strategy to reduce the cost of the weed control practices, and avoid herbicides injury to the crop and herbicide resistance of some weeds [9,12,13]. Research conducted at ICARDA [9,14] resulted in the identification of accessions that tolerate metribuzin and/or imazethapyr herbicides.…”

“…The development of resistant cultivars to multiple herbicides with different modes of action [9][10][11] is still the most economical and environmentally friendly control strategy to reduce the cost of the weed control practices, and avoid herbicides injury to the crop and herbicide resistance of some weeds [9,12,13]. Research conducted at ICARDA [9,14] resulted in the identification of accessions that tolerate metribuzin and/or imazethapyr herbicides. However, demonstrating the adaptability of these accessions to a wide range of environments can increase their economic value as climate change is expected to reduce the production of faba bean in many regions.…”