Effect of soil interacting herbicides on soybean nodulation in Balcarce, Argentina

Abstract

-Two trials were performed in Balcarce, Argentina (37° 45' LS; 58° 18' LW) during 1993-94, to assess the effect of eight herbicides applied individually or in tank mixtures, on nodule number, nodule dry weight, seed yield and N percent in seed in soybean Asgrow 3205, inoculated with Bradyrhizobium japonicum CB 1809. Individual herbicides and doses in kg ha -1 of a.i. were metribuzin (0.48), acetochlor (0.90), metolachlor (1), flumioxazin (0.075), trifluralin (0.96), imazaquin (0.20), imazethapyr (0.10) and chlorimuron ethyl (0.0125). The mixtures were metribuzin+acetochlor (0.48+0.9), flumioxazin+acetochlor (0.075+0.9), imazaquin+acetochlor (0.2+0.9), metribuzin+metolachlor (0.48+1.92), and flumioxazin+ metolachlor (0.075+1.92). A control treatment without herbicides was included. Both trials were laid out as randomized complete blocks with four replicates, on a loam illitic thermic petrocalcic Paleudoll, 5.7% organic matter (OM), 25% clay, 30.4 cmol kg -1 CEC. Nodules were sampled at V2 (second node), V6 (sixth node) and R5 (beginning seed) growth stages. Herbicides did not significantly affect the beginning of nodulation or nodule number and mass at R5, not either grain yield or N accumulation. This indicates lack of interference between soil interacting herbicides and N fixation in the high organic matter, loam soils of SE Buenos Aires province, even though a tendency in less number and dry weight of nodules was evident at the two latter growth stages. (0,20), imazathapyr (0,10) e chlorimuron ethyl (0,0125). As misturas foram metribuzin+acetochlor (0,48+0,9), flumioxazin+acetochlor (0,075+0,9), imazaquin+acetochlor (0,2+0,9), metribuzin+metolachlor (0,48+1,92), e flumioxazin+metolachlor (0,075+1,92). Incluiu-se um controle sem herbicidas. Os experimentos foram conduzidos no delineamento em blocos completos ao acaso, com quatro repetições. Usou-se um solo Paleudol petrocálcico, franco, ilítico, térmico, com matéria orgânica 5,7%, argila 25%, e CTC 30,4 cmol kg -1 . Os nódulos foram amostrados em V2 (segundo nó), V6 (sexto nó) e R5 (começo de semente). Os herbicidas não alteraram o início da nodulação nem o número ou peso dos nódulos em R5, e também não houve efeito no rendimento de grãos, o que sugere que não há interferência entre eles e fixação de N nos solos francos com alto conteúdo de matéria orgânica do sudeste de Buenos Aires. Por outro lado, evidenciou-se uma tendência à formação de menos nódulos e menor peso dos nódulos, nos dois últimos níveis de crescimento.Termos para indexação: Bradyrhizobium japonicum, lesões por herbicidas, fixação de N, rendimento.

Flumioxazin, imazethapyr and their mixture in the rhizosphere of soybean: effect on early nodulation and biological N fixation

“…Particularly, some previous studies found that imazethapyr, even when applied at recommended rates, decreased the nodulation in soybean (Parsa et al, 2013;Gonçalves et al, 2018). The results disagree with Gonzalez et al, (1999) who applied flumioxazin, at recommended rate, and did not observe negative effect on nodulation in inoculated soybean. Thus, these different results found in this study those observed by Gonzalez et al, (1999) can be explained by the absence of inoculation.…”

“…However, Gonçalves et al (2018) reported imazethapyr decreasing the root system and nodulation in soybean. In the case of flumioxazin, Gonzalez et al (1999) reported a decreased nodulation with its application on soybean field.…”

Influence of Aclonifen on the Growth of <i>Rhizobium </i><i>Phaseol</i><i>ii</i> and the Yield of Green Beans (<i>Phaseolus</i><i> Vulgaris</i> L.)

“…Since herbicides are necessary to achieve maximu m y ield, their in fluence on nodulation may conflict with the crop managements [10]. Herbicide applicat ion is very co mmon in bean production.…”

Soil microbial biomass C and symbiotic processes associated with soybean after sulfentrazone herbicide application

“…Recently, Arruda et al (2001) demonstrated that nodule number and nodule dry weight in soybean decreases as a function of increased rates of the herbicide sulfentrazone. On the other hand, Gonzalez et al (1999) have not found effects of the herbicides metribuzin, acetochlor, metolachlor, trifluralin, imazaquin, imazethapyr, and chlorimuron ethyl on soybean nodulation and consequently on yield, in soil with high organic matter content. Similarly, Malty et al (2006) did not observe an effect of the herbicide glyphosate, a inhibitor of 5-enolpyruvylshikimate-3-phosphate synthase, on soybean nodulation.…”