Joint use of fungicides, insecticides and inoculants in the treatment of soybean seeds

Abstract

Joint use of fungicides, insecticides and inoculantsin the treatment of soybean seeds 1 The interference of the joint application of pesticides with seed inoculation on the survival of Bradyrhizobium has been reported in the last years. So, the objective of this study was to evaluate the joint use of fungicides, insecticides and inoculant in the treatment of soybean seeds on various parameters of Bradyrhizobium nodulation in soybean as well as on crop productivity parameters. Uso conjunto de fungicidas, inseticidas e inoculante no tratamento de sementes de sojaNos últimos anos têm surgido relatos sobre a interferência da aplicação de defensivos agrícolas em conjunto com a inoculação das sementes de soja na sobrevivência dos Bradyrhizobium. Dessa forma, o presente trabalho teve por objetivo avaliar o efeito do uso conjunto de fungicidas, inseticidas e inoculante no tratamento de sementes de soja sobre vários características da nodulação de Bradyrhizobium na soja e, também, em parâmetros de produtividade da cultura. O experimento foi realizado durante a safra 2013/2014 no campo experimental do Instituto Federal de Educação, Ciência e Tecnologia de Mato Grosso -Campus Campo Novo do Parecis. A semeadura foi realizada em vasos, com a variedade TMG 133 RR. Adotou-se o delineamento em blocos casualizados, em esquema fatorial 4 x 4 + 1, sendo quatro fungicidas (1: fludioxonil + metalaxil-M, 2: carboxina + thiram, 3: difeconazol e 4: carbendazim + thiram), quatro inseticidas (1: fipronil 250 SC, 2: thiamethoxam, 3: imidacloprido + tiodicarpe e 4: imodacloprido 600 FC) e um inoculante (SEMIA 5079 e SEMIA 5080), comum a todos os tratamentos, com três repetições. O experimento não foi repetido. A aplicação conjunta de fungicida e inseticida com inoculante não prejudica a nodulação, o teor de N foliar e crescimento vegetativo das plantas, assim como as massas de grãos por planta e de 100 grãos. O uso das misturas carbendazim + 259 Joint use of fungicides, insecticides and inoculants in the treatment of soybean seeds Rev. Ceres, Viçosa, v. 64, n.3, p. 258-265, mai/jun, 2017

Seed treatment and pre-inoculation of soybean: effect of storage period and agrochemicals on the physiological quality of seed and yield

“…Seed treatments with fungicide and insecticides can be used in an integrated management program to control diseases and pests as a preventative tactic. According to a survey performed in Brazil, some advantages of the use of industrial seed treatments have been related to higher efficiency of the sowing process, economy of labor and time, lower risk of intoxication by growers, higher precision regarding to the dose used, more uniform coverage of the seeds, reduction of production costs, guarantee of acquisition of seeds with good quality, combat seed piracy, among others (França-Neto et al, 2015).…”

“…Hence, seed treatment has been considered as a cost-effective tool that can be used to manage pests and diseases that occur soon after sowing (Goulart, 1998;Pereira et al, 2010a). Industrial seed treatment of soybean is a practice that has gained more prominence over the last years (França-Neto et al, 2015). Immediately after processing, seed producer companies treat, bag and then store the seeds until sowing (Conceição et al, 2016;Brzezinski et al, 2017).…”

Pre-inoculation of soybean seeds: Effects on survival of Bradyrhizobium elkanii, nodulation and crop yield

“…However, when fungicides and insecticides are added to the seed, the viability of the nitrogen-fixing bacteria could be jeopardized to a point where the number of viable bacteria is not enough to infect the plant effectively and form nodules (Hartley et al, 2012;Araujo et al, 2017). Thus, the compatibility of fungicides and insecticides represents a great challenge to the seed treatment (Campo et al, 2009;Pereira et al, 2010a;Silva Neto et al, 2013;Gomes et al, 2017). Very few studies were performed to evaluate the association of pre-inoculation and industrial seed treatment (Anghinoni et al, 2017;Machineski et al, 2018), and little is known about the maximum period of time before sowing that the seed could be treated without compromising the viability of the bacteria, nodulation of the plants and soybean yield (Pereira et al, 2010b;Zilli et al, 2010).…”

“…Certain combinations of fungicides (Campo et al, 2009;Gomes et al, 2017;Costa et al, 2013) as well as insecticides (Pereira et al, 2010c) can be detrimental to Bradyrhizobium spp. due to the toxicity of the active ingredient, pH and solvents used in the formulations (Hungria and Campo, 2000), but the magnitude of the effect depends on the type and the period of contact between the chemicals and the inoculant (Costa et al, 2013).…”

Determination of toxicity of various preparative forms of pesticidal fungicides for nodule bacteria inoculants

“…It is worth noting that the absence of an obvious toxic effect of the fungicide on rhizobia in a joint tank solution does not guarantee the absence of negative consequences for nodule formation in the field [40][41][42]. For example, a number of studies have described the inhibitory effect of the fungicide Maxim on the intensity of nodule formation in inoculated soybean plants [24], despite the fact that seed treatment and inoculation were separated in time.…”