ABSTRACT.- Context:In the temperate-humid region of Argentina, nitrogen (N) fertilisers in maize (Zea mays L.) are mainly applied around sowing, whereas N-splitting is rare and occurs during early vegetative stages. Splitting and late N fertilisation, even up to silking (R1), effects on yield have been recently studied. However, to the extent of our knowledge, these studies have mainly focused on the effect of these strategies on maize yield, but less on the crop N economy.

ABSTRACT.- Colloquially known as Soybean Stem Fly, Melanagromyza sojae (Zehntner, 1901) (Diptera, Agro-myzidae) is an oligophagous pest of plants in the family Fabaceae, including Uruguay?s biggest commodity crop, Soybean (Glycine max (L.) Merr.). To our knowledge, this is the first scientific record of M. sojae in Uruguay, and we confirm its identity through using DNA barcoding. Characteristic damage to host plants and immature stages of M. sojae were confirmed in Dolores and Colonia, Uruguay. © The authors.

ABSTRACT.- Conyza bonariensis L. (hairy fleabane) is a significant weed in production systems, especially due to its evolving resistance to various herbicides. In Uruguay, control failures of C. bonariensis have been reported following the use of glyphosate and ALS inhibitors. The objective of this study was to investigate the occurrence of the multiple and cross-resistance of C. bonariensis to glyphosate, chlorimuron, and diclosulam, and to assess the efficacy of alternative herbicides against these resistant biotypes.

ABSTRACT.- Conyza bonariensis L. (hairy fleabane) is a significant weed in production systems, especially due to its evolving resistance to various herbicides. In Uruguay, control failures of C. bonariensis have been reported following the use of glyphosate and ALS inhibitors. The objective of this study was to investigate the occurrence of the multiple and cross-resistance of C. bonariensis to glyphosate, chlorimuron, and diclosulam, and to assess the efficacy of alternative herbicides against these resistant biotypes.

ABSTRACT.- Bt soybean cultivation is increasing worldwide. The Cry1Ac protein expressed in Bt soybean efficiently controls several lepidopteran pests. The stink bug, Piezodorus guildinii (Westwood), a major pest for soybean in the Americas, is not controlled by Bt crops, although possible sub-lethal effects may occur. Even if there were no negative effects for sting bug, ingesting toxins could affect its bio-controllers. We tested through ELISA detection if P. guildinii ingests Cry1Ac from Bt soybean and possible effects on its development, reproduction, survival, and feeding behavior.

ABSTRACT.- Bt soybean cultivation is increasing worldwide. The Cry1Ac protein expressed in Bt soybean efficiently controls several lepidopteran pests. The stink bug, Piezodorus guildinii (Westwood), a major pest for soybean in the Americas, is not controlled by Bt crops, although possible sub-lethal effects may occur. Even if there were no negative effects for sting bug, ingesting toxins could affect its bio-controllers. We tested through ELISA detection if P. guildinii ingests Cry1Ac from Bt soybean and possible effects on its development, reproduction, survival, and feeding behavior.

ABSTRACT.- Pasture persistence is a key determinant of the economic and environmental performance of pastoral animal production systems. Large and deep root systems that help resist summer water stress have been proposed as a relevant trait for vegetative persistence of perennial temperate forage species growing in subtropical climates or under future climatically challenging scenarios. In a previous study [Jauregui et al., 2017. Persistence of tall fescue in a subtropical environment: Tiller survival over summer in response to flowering control and nitrogen supply.

ABSTRACT.- Pasture persistence is a key determinant of the economic and environmental performance of pastoral animal production systems. Large and deep root systems that help resist summer water stress have been proposed as a relevant trait for vegetative persistence of perennial temperate forage species growing in subtropical climates or under future climatically challenging scenarios. In a previous study [Jauregui et al., 2017. Persistence of tall fescue in a subtropical environment:Tiller survival over summer in response to flowering control and nitrogen supply.

ABSTRACT.- CONTEXT:Monitoring Aboveground Net Primary Production (ANPP) is critical to assess not only the current ecosystem status but also its long-term dynamics. In rangelands, the seasonal dynamics of ANPP determines forage availability, stock density, and livestock productivity. OBJECTIVE:To develop a hybrid model to be used as a prediction engine for ANPP in the native grasslands of Uruguay.

ABSTRACT.- CONTEXT: Monitoring Aboveground Net Primary Production (ANPP) is critical to assess not only the current ecosystem status but also its long-term dynamics. In rangelands, the seasonal dynamics of ANPP determines forage availability, stock density, and livestock productivity. OBJECTIVE: To develop a hybrid model to be used as a prediction engine for ANPP in the native grasslands of Uruguay.