Fungicide Applications and Grain Dry Milling Quality in Late‐Sown Maize

Abstract

Argentinean maize (Zea mays L.) is known for its grain hardness, and exporting grain lots are subject to strict regulations regarding physical characteristics and mycotoxin concentrations. Our production system is changing to later sowings, and the use of foliar fungicides is becoming more common due to positive yield responses. In this study, we evaluated the effects of fungicide treatments at different application timing on specific physical grain quality traits and fumonisins in late‐sown maize. For this we used four commercial genotypes differing in grain hardness. Measured traits were yield, individual grain weight, dry milling grain quality attributes (test weight, floaters, vitreousness, and 8‐mm screen retention), grain composition (oil, protein, and starch), and total fumonisin concentrations. Yield was affected by genotype and fungicide treatments (p < 0.05). Genotypes differed (p < 0.001) in all grain quality attributes and fumonisin concentrations. Particular genotypes had fumonisin values higher than maximum levels accepted for human consumption (4 μg g−1). Fumonisin concentration differences among genotypes were negatively related to their grain hardness. Fungicide treatments, regardless of type and application timing, increased yield in all genotypes by ∼350 kg ha−1. However, fungicides had no significant positive effect on any grain physical quality trait, or on fumonisin concentrations. These results emphasize the importance of genotype selection as a critical crop management option to manage grain physical quality traits and fumonisin contaminations. Fungicides can positively affect yield, but positive effects on dry milling grain quality should not always be expected.

Management options for reducing maize yield gaps in contrasting sowing dates

“…Maize sown at LS is more susceptible to foliar diseases. In our study we found an important yield response to the use of fungicides, more than two times higher than the effect recently reported by other authors (Abdala et al, 2018), but coincident with other local specific studies testing fungicide yield responses across commercial genotypes (Accame et al, 2019). Fungicide…”

“…The use of foliar fungicides has proved to increase yields at several environments (Paul et al, 2011;Ruffo et al, 2015;Abdala et al, 2018). The yield response depends on growing conditions and genotype (Munkvold et al, 2001;Ruffo et al, 2015).…”

“…Stand density and nitrogen (N) fertilization are known to be important management decisions for ES (Cirilo and Andrade, 1994;Calviño et al, 2003) and LS (Caviglia et al, 2014;Gambin et al, 2016;Coyos et al, 2018;Maltese et al, 2019). In LS, crop protection is supposed to be more relevant due to the higher disease pressure (Abdala et al, 2018). Water availability appears among environmental important variables in ES (Podestá et al, 1999;Maddonni, 2012;Florio et al, 2014), while its yield effect in LS is limited (Gambin et al, 2016).…”

The Effect of Foliar Fungicide and Insecticide Application on the Contamination of Fumonisins, Moniliformin and Deoxynivalenol in Maize Used for Food Purposes

“…Masiello et al [ 20 ] reported that prothioconazole, when applied at silking, was effective in reducing F. graminearum and F. proliferatum infection, while it was less effective against F. verticillioides . In Argentina, metconazole and epoxiconazole applied at silking (GS65) did not affect the FB content for either natural infection or after inoculation with F. verticillioides [ 37 ]. The application of a fungicide in a mixture with an insecticide at the maize silking stage did not significantly affect the FB contamination, compared to the application of insecticide alone [ 17 , 18 , 22 ].…”