The effect of seed treatments on wireworm (Elateridae) performance, damages and yield traits of sunflower (Helianthus annuus L.)

Abstract

Sunflower seed treatments are inevitable measure that ensures protection from soil-dwelling insects and pathogens at the first stages of plant development. Due to the ban of neonicotinoid based insecticides for the sunflower seed treatments, new registered preparations are put to test. The aim of this work was to assess the efficacy of currently registered insecticides against the wireworms (observed in field emergence and percent of damaged plants) and their effect on yield traits (yield, oil content and 1,000-seed weight) of the sunflower hybrids (Sumo 2 OR, Oliva and Novak) in comparison to previously used neonicotinoids. Seeds were treated with different pesticidal combinations: metalaxyl-m, metalaxyl-m + bifenthrine, metalaxyl-m + thiacloprid, metalaxyl-m + thiametoxam, and metalaxyl-m + imidacloprid. Twoway ANOVA and Duncan's multiple range tests were performed. Field emergence was not influenced by the treatment. Sumo 2 OR and Oliva emergence did not differ significantly among the treatments (78.3-88.3%; 83.0-91.3%, respectively), but for Novak it was significantly lower (79.3%) when treated with metalaxyl-m. The lowest percent of damaged plants was in the treatment with metalaxyl-m + thiametoxam (1.1-2.4%). However, it did not differ significantly among other treatments (2.4-3.9%), regardless on the hybrid. Novak had the highest average yield (3,938.1 kg/ha), followed by Sumo 2 OR (3,566.1 kg/ha), and Oliva (3,199.8 kg/ha), regardless on the applied seed treatments. The highest 1,000-seed weight was measured for Oliva. Given indicates that currently registered insecticides for the seed treatment of sunflower, such as Sonido and Semafor, can be adequate substitute to the banned neonicotinoids like Cruiser and Gaucho.

Comparison of Chemical and Biological Wireworm Control Options in Serbian Sunflower Fields and a Proposition for a Refined Wireworm Damage Assessment

“…Depending on the experimental year, the percentage of damaged plants in the ATTRACAP ® treatment was either on the same level as in other chemical treatments or higher but significantly lower than in the untreated control. The percent of damaged sunflower plants was proven to be dependent on the applied treatment as already reported by Gvozdenac et al (2019) [31], which is in accordance with our results. In a 2-year study, Brandl et al (2017a) [37] applied the "A&K" strategy using ATTRACAP ® against wireworms in organic potato production systems in Lower Saxony, Germany.…”

“…These strategies aim at reducing wireworm densities below the economic threshold and require a combination of agronomic practices with a partial impact and can be achieved through long-term management [5,27]. One of the promising alternatives is the use of entomopathogenic fungi (EPFs) as environmentally favourable microbiological control agents [28][29][30][31]. Several naturally occurring soil inhabiting microorganisms, such as species from the genera Metarhizium and Beauveria, have been well studied and proven to be effective against wireworms [32][33][34][35][36][37][38][39].…”

Tratamentos pré-germinativos em sementes de cenoura com bioativador

“…In sorghum seeds, treatment with 7 mL of Cruiser ® resulted in excellent germination with 99% seedling emergence (Perales-Rosas et al, 2019). The same neonicotinoid is considered crucial in sunflower treatment at a product concentration of 350 g L -1 due to its benefits during early development (Gvozdenac et al, 2019). The beneficial effects of thiamethoxam may also be related to the water balance of seeds, absorption of water during the mobilization of reserves, and activation of proteins involved in the defense mechanism (Almeida et al, 2014).…”

Effects of harmful Bangasternus planifrons (Brulle, 1832) (Coleoptera: Curculionidae) control with different insecticides on yield and quality in safflower

“…(Hemiptera: Aphididae) causes loss in yield in safflower and that among the five different insecticides applied for control, thiamethoxam active exhibited the highest effect as 0.83 aphids per 5 cm plot, while an average of 66.13 aphids per 5 cm plot was found in the control plots (Gore et al 2010). In the study conducted by Gvozdenac et al (2019) to control wireworm in sunflower [Helianthus annuus L. (Asterales: Asteraceae)], 15.8% damaged plants were found in control and 1.86% in thiamethoxam application. Showler and Robinson (2005) stated that the application of insecticides in cotton [Gossypium spp.…”

“…The oil rate increased by 5.4-6.9% and that the oil quality was not affected by insect damage. Gvozdenac et al (2019) stated that the damage of wireworms in sunflower was reduced with thiamethoxam application when compared to the control and that the applications did not differ from the control in the oil rate F=34.982; P=0,081; df=2 F=0.969; P=0,416; df=2 F=0.940; P=0,426; df=2 F=19.792 F=1.025; P=0,397; df=2 F=2.040; P=0,186; df=2 F=1.656; P=0,244; df=2 F=12.844; P=0,002; df=2 * Different capital letters in a column were significantly different (P<0.05) ** Different small letters in a line were significantly different (P<0.05) and 1000-grain weight. In a study conducted on winter canola, they found that insecticide application increased the yield, but there was no change in 1000 grain weight (Leach et al 1994).…”