RESUMOPalavras-chave adicionais: Diplodia, resistência genética, Stenocarpella macrospora, Zea mays A mancha-de-macrospora, causada pelo fungo Stenocarpella macrospora, tem se mostrado frequente e importante na cultura do milho no Brasil. A resistência genética é uma das principais estratégias de controle de doenças foliares do milho. No Brasil, são escassas as informações sobre resistência de híbridos à S. macrospora. O objetivo deste trabalho foi avaliar a reação de 25 híbridos de milho à mancha-de-macrospora. O experimento foi conduzido em 2011, em casa de vegetação com condições controladas de temperatura e umidade relativa do ar. O delineamento experimental foi inteiramente casualizado, com cinco repetições, sendo as unidades experimentais constituídas por um vaso com cinco plantas. A inoculação foi feita no estádio fenológico V2 (duas folhas totalmente expandidas), depositando no cartucho de cada planta 2,0 mL da suspensão de 1,8x10 4 conídios mL Macrospora leaf spot, caused by the fungus Stenocarpella macrospora, has shown to be frequent and important among corn fields in Brazil. Genetic resistance is one of the main strategies to control corn leaf diseases. In Brazil, there is scarce information on the resistance of hybrids to Stenocarpella macrospora. The aim of this study was to evaluate the reaction of 25 corn hybrids to macrospora leaf spot. The experiment was conducted in 2011, in a greenhouse under controlled temperature and relative humidity conditions. Experimental design was completely randomized, with five replicates, each experimental unit consisting of a pot with five plants. Inoculation was done in the V2 growth stage (two fully expanded leaves), and the whorl of each plant received 2.0 mL suspension of 1. Additional keywords: Diplodia, genetic resistance, Stenocarpella macrospora, Zea mays ABSTRACT fungal isolates were obtained from infected crop residues at the municipalities Lages and Quilombo, Santa Catarina State, and Campinas do Sul and Vacaria, Rio Grande do Sul State. Disease severity was assessed at 21 days after inoculation in the V4 stage (four fully expanded leaves). No tested hybrid was totally resistant to the fungus S. macrospora. There was a significant difference in the disease severity between hybrids and fungal isolates. Hybrids inoculated with Quilombo isolate showed four reaction groups, while the isolates Vacaria, Lages and Campinas do Sul showed two groups. Some hybrids had varied behaviors against the isolates, suggesting different aggressiveness levels. There were hybrids that showed similar reaction to the isolates, suggesting greater stability for macrospora leaf spot.O milho (Zea mays L.) é uma das principais culturas exploradas no Brasil. A importância desse cultivo é caracterizada pela sua utilização na alimentação humana e animal. A área semeada e a produção vêm aumentando nas últimas décadas, porém a produtividade brasileira é considerada baixa se comparada ao potencial produtivo da cultura (9, 12).As doenças foliares afetam a produtividade do milho (2, 13). A...

No abstract

Asian soybean rust is the major crop disease and the management of the use of the fungicide is important for effective control. The objective of this work was to evaluate the management of fungicides with sequential applications to control Asian soybean rust. The experimental design used was a randomized block with four replications and eight treatments with different combinations of fungicides from the following chemical groups: triazole, strobilurin, carboxamide, and dithiocarbamate. The applications were carried out with backpack spray equipment at constant pressure (CO2) and a spray rate of 200 L ha-1. The severity of rust, the area under the disease progress curve, control efficiency, mass of 1,000 grains, and productivity were evaluated. The protective fungicide mancozeb, in mixtures with systemic fungicides, were more effective for the control of Asian soybean rust than the systemic fungicides applied without the protective fungicide.

Crop rotation consists of alternating plant species cultivation in the same agricultural land, aiming to provide nutrient replenishment in the soil through organic matter deposition, as well as mitigating the soil degradation caused by agricultural practices. However, due to the short list of known crops suitable for such application, a selection of species to be inserted to the system is of critical importance. The objective of this research was to study the agronomic performance of soybean in crop rotation systems. The experiment was conducted at the Experimental Farm of the Faculty of Agricultural Sciences of UFGD, Dourados-MS, in two cropping seasons: 2013/2014 and 2014/2015; using a randomized block design with thirteen treatments and four replications. Treatments consisted of crop rotation systems in two soybeans cropping seasons. Corn, brachiaria, canola, wheat, forage turnip, safflower, crotalaria, niger, crambe, white oat, vetch and sunflower were the selected species to be inserted in the rotation systems. Six variables were analyzed: plant height, height of first pod insertion, number of branches per plant, number of pods per plant, mass of 1000 grains and grain yield. All collected data was submitted to analysis of variance and the means comparisons were analyzed by the Scott-Knott test (5%). This study revealed that crop rotation is an agricultural technique that favors the grain yield of soybean. Furthermore, during autumn and winter, fallowing is not recommended for soybean cultivation

Maize grown in the summer can be an important option for crop rotation with soybean. The objective of this work was to study the agronomic performance of maize in different crop rotation systems. The experiment was conducted at the Experimental Farm belonging to the College of Agricultural Sciences of the Federal University of Grande Dourados (UFGD), located in the municipality of Dourados, MS, in the agricultural year of 2014/15. Randomized block design was used, with ten treatments and four replications. The treatments consisted of precedent crops: white oat (Avena sativa), forage radish (Raphanus sativus L. var. oleifera), showy rattlebox (Crotalaria spectabilis), fodder vetch (Vicia villosa), crambe (Crambe abyssinica), safflower (Carthamus tinctorius L.), niger (Guizothia abyssinica), canola (Brassica napus L. var. oleifera), wheat (Triticum aestivum L.) and fallow. These crops were planted in the fall/winter season of each agricultural year, while maize was sown in October of each year. Plant height, ear insertion height, ear length and diameter, grains per ear, thousand grain weight and yield were evaluated. There was significant difference only for yield, which presented the highest values in the rotation with safflower, canola, forage radish, wheat, white oat and niger.

O algodoeiro é cultivado tradicionalmente em espaçamentos variam 0,76 a 0,90 m entre linhas. O algodoeiro adensado e ultra-adensado são cultivados com espaçamentos entre fileiras menores que o convencional. O objetivo deste trabalho foi avaliar fatores morfológicos da cultura do algodão relacionado ao cultivo ultra-adensado, adensado e convencional em função do ângulo de aplicação do pulverizador para controle de pragas. O trabalho foi realizado na Fazenda Experimental da Universidade Federal da Grande Dourados no município de Dourados, MS, na safra 2010/2011 e 2011/2012. O delineamento experimental utilizado foi parcelas sub-subdivididas com 4 repetições, no esquema fatorial 3 x 4. Os sistemas de cultivos foram divididos em relação ao espaçamento entrelinha (0,22, 0,45 e 0,90 m). Os ângulos de aplicação foram divididos em: 0º (paralela à linha de cultivo), 30º e 45° (diagonal em relação à linha de cultivo) e 90º (perpendicular em relação à linha de cultivo). Os dados foram submetidos à ANOVA (p<0,05), quando significativo, efetuou a aplicação do teste de Tukey (p<0,05). A altura das plantas de algodão é influenciada pelo adensamento de plantas no espaçamento de 0,22 m entrelinhas; O ângulo de caminhamento de aplicação de 0° ocasiona o maior amassamento de folhas no espaçamento de 0,22 m e menor amassamento no espaçamento de 0,90 m; O número de estruturas reprodutivas foi maior no espaçamento de 0,90 m entre linhas; A produtividade de algodão em caroço foi maior no espaçamento entre linhas de 0,22 m.

The control of Asian soybean rust depends on fungicide efficacy and the application technology; however, the leaf architecture of soybean cultivars may also interfere in disease control. This study aimed to evaluate Asian rust control and fungicide deposition using spray nozzles in three soybean cultivars. A randomized block design was used, with treatments arranged in a split-plot scheme; the plots were three soybean cultivars (SYN 1561 IPRO, M6410 IPRO, and M6210 IPRO) and the subplots three spray nozzles (11002 BD, AIXR 110015 and TTJ60 11002), in addition to a control with no fungicide application, and four replicates. The volume median diameter, droplet coverage, leaf area index, area under the disease progress curve, 1,000-grain weight and crop yield were evaluated. The 11002BD and AIXR11005 nozzles provided better spray deposition in cultivars with lower leaf area indexes at the R1 phenological stage. Nozzles 11002BD, AIXR110015 and TTJ60 ensured better management of Asian rust than that of the control treatment, regardless of leaf area index. Cultivar SYN1561 obtained the largest grain yield and highest leaf area index in the season with the highest rainfall, regardless of the spray nozzle used.

The displacement velocity of the tractor-seeder set, associated with the furrowing mechanism, influences the plant distribution and the establishment of a correct plant stand in the field. The objective of this study was to evaluate the operational performance of a seeder-fertilizer in the non-tillage sunflower crop, according to sowing speeds and furrow mechanisms. The experimental design used was the randomized blocks, with treatments arranged in a split-plot scheme, where the plots were the furrowing mechanisms (chisel openers and double disk) and the subplots were the sowing speeds (3.2; 4.6; 6.2 and 7.0km h-1), with three replicates. The following were determined in this study: the emergence speed index, the emergence in the field, the average distance between the plants, plant height, plant population and the longitudinal distribution of plants. Sunflower sowing using a chisel openers provides greater emergence in the field, emergence speed index and, consequently, greater plant population. Sowing speed ranging from 3.2 to 7.0km h-1 do not influence field emergence, emergence speed index, height and population of sunflower plants.