Can Brazil produce enough rice to meet demand in 2028?

The objectives of the study were estimate the additional yield that may be achieved by reducing the yield gap in actual rice area, evaluate if irrigated rice production meet future demand for rice without increase area and determine sowing date that allows maximum yield potential. The yield gap (Yg) was determined by the difference between yield potential (Yp) and actual yield (Ya). The Ya was obtained from surveys applied to the rice producers. The Ya was 51% of Yp, and the Yg was 49%. In a scenario of high demand, if the yields follow the historical rate of gain, the production should not be sufficient to meet projected demand without 6% expansion of the currently cultivated area, whereas for a scenario of low demand it should be sufficient. Moreover, for the low and high demand scenarios, if the national average yield reaches 80% of the rice Yp, a reduction until 29% in the current irrigated rice area can occur. Sowing between September and mid-November is a way of making it possible to obtain yields close to 80% of Yp without increasing production costs. This study can be used as an aid in the search for world food security

Agronomic performance of irrigated rice hybrids on the Western border of Rio Grande do Sul

The objective of this work was to compare the agronomic performance of three cultivars of irrigated rice, two hybrids and one conventional in the municipality of Uruguaiana, west border of Rio Grande do Sul. The experiment was conducted in the 2017/2018 harvest in a completely randomized design with four repetitions. The three treatments were the cultivar Guri Inta CL, and the hybrids Titan CL and Lexus CL. Plant morphological traits (plant length, panicle length, grain length, grain width, grain appearance) as well as yield components (weight of one thousand grains, number of grains per panicle, number of grains broken per panicle , plant population, yield of whole grains). For the variables of appearance and grain size, the statistical analyzer S-21 was used. The three varieties did not differ statistically for productivity, however they differed in other aspects such as yield of whole grains, initial population of plants and aspects of appearance and dimensions of grains, where the cultivar Guri Inta CL was superior, and the hybrids did not differ among themselves. As the hybrids had a lower initial plant population, compensated in other characters, the cultivar Titan presented a greater number of tiller than the other cultivars, while the Lexus cultivar had a higher number of spikelets per panicle, more branches per panicle and weight of thousand grains.Rice crops are essential in World Food Security. Brazil is the largest rice producer outside Asia, with increasing research investments, including using hybrid cultivars with high productive potential. The objectives of this study were to compare the agronomic performance of three cultivars of irrigated rice, two hybrids and one conventional, in the municipality of Uruguaiana, on the western border of Rio Grande do Sul. The experiment was conducted in the 2017/2018 crop with four replicates in a completely randomized design. The three treatments consisted of the cultivar Guri Inta CL and the hybrids Titan CL and Lexus CL. Morphological characters (plant stature, panicle length, grain length, grain width, grain appearance) and yield components (weight of one thousand grains, number of grains per panicle, number of sterile grains per panicle, plant population, whole grain yield) were evaluated. The statistical analyzer S-21 was used to determine the variables of appearance and grain size. The agronomic performance of hybrid cultivars presents lower quality for whole grain yield and the percentage of chalky grains. The morphological characteristics of the plant indicate that hybrid cultivars compensate for the lower initial population by producing more branches and larger panicles without compromising grain yield. Grain yield showed no significant difference, demonstrating the lack of economic viability in this agricultural year for cultivating rice hybrids in Uruguaiana. Significant correlations were verified between the productive characteristics and rice grain quality, showing the relationships between grain productivity and rice grain quality

Tolerância de cultivares de soja ao estresse por alagamento em estádios de crescimento vegetativo

The objective of this work was to evaluate the tolerance of soybean (Glycine max) cultivars to flooding stress at different growth stages. The experiment was arranged in a 2x2x5 factorial arrangement, with two sowing dates (October and November), two soybean cultivars (TECIRGA 6070RR and NA 5909 RG), and five growth stages (SE–EM, EM–VC, VC–V2, V2–V4, and V6–V8) in the 2018/2019 and 2019/2020 crop years. The experimental design was completely randomized with four replicates. For both evaluated soybean cultivars, the growth stage most sensitive to soil flooding was SE–EM. After seedling emergence, the highest reductions in leaf area and shoot dry matter were observed in the V2–V4 stage, regardless of cultivar, sowing date, and crop year. From the V4 stage onwards, soybean shows a higher tolerance to flooding conditions. However, after seedling emergence, the TECIRGA 6070RR cultivar has a higher tolerance to flooding stress than NA 5909 RG. Sowing in October tends to reduce the impact of flooding stress on the plants.O objetivo deste trabalho foi avaliar a tolerância de cultivares de soja (Glycine max) ao estresse por alagamento, em diferentes estádios de crescimento. O experimento foi realizado em arranjo fatorial 2x2x5, com duas épocas de semeadura (outubro e novembro), duas cultivares de soja (TECIRGA 6070RR e NA 5909 RG) e cinco fases de desenvolvimento (SE–EM, EM–VC, VC–V2, V2–V4 e V6–V8), nos anos agrícolas 2018/2019 e 2019/2020. O delineamento experimental foi inteiramente casualizado com quatro repetições. Para ambas as cultivares avaliadas, o estádio de crescimento mais sensível ao alagamento do solo foi o SE–EM. Após a emergência das plântulas, as maiores reduções de área foliar e matéria seca de brotos foram observadas no estádio V2–V4, independentemente de cultivar, época de semeadura e ano agrícola. A partir do estádio V4, a soja apresenta maior tolerância às condições de alagamento. No entanto, após a emergência das plântulas, a cultivar TECIRGA 6070RR apresenta maior tolerância ao estresse por inundação do que a NA 5909 RG. A semeadura em outubro tende a reduzir o impacto do estresse por inundação nas plantas

Manejo de plantas daninhas e fertilidade limitam o potencial de produtividade da mandioca em ambiente subtropical

The objectives of this study were to evaluate the response to fertilization and different weed control periods in the accumulation of dry matter of cassava leaves, stems, roots, and fresh mass roots yield. Two experiments were carried out on commercial fields in Ibarama, and Santa Maria municipalities located at the Rio Grande do Sul State, South Brazil, during the 2018/2019 growing season. Five treatments, varying chemical fertilizer applications and herbicides were used to represent management practices commonly used by farmers in Southern Brazil. The Simanihot process-based model simulated cassava growth, development, and productivity under potential conditions. Results show that the recommended dose of fertilizers and liming combined with pre-emergent herbicide and three mechanical weed clear management showed a 72% increase in root productivity compared to the management used by the average yield of smallholder farmers. Therefore, it is possible to reach 80% of the potential productivity by keeping the cassava crop free from weed interference and applying fertilizers. The presence of weeds during the first 100 days after planting reduced about 50% of the plant dry matter production in Ibarama and Santa Maria. Interestingly, it also affects 79.2% of fresh roots productivity in Ibarama. The objectives of this study were to evaluate the response to fertilization and different weed control periods in the accumulation of dry matter of cassava leaves, stems, roots, and fresh mass roots yield. Two experiments were carried out on commercial fields in Ibarama, and Santa Maria municipalities located at the Rio Grande do Sul State, South Brazil, during the 2018/2019 growing season. Five treatments, varying chemical fertilizer applications and herbicides were used to represent management practices commonly used by farmers in Southern Brazil. The Simanihot process-based model simulated cassava growth, development, and productivity under potential conditions. Results show that the recommended dose of fertilizers and liming combined with pre-emergent herbicide and three mechanical weed clear management showed a 72% increase in root productivity compared to the management used by the average yield of smallholder farmers. Therefore, it is possible to reach 80% of the potential productivity by keeping the cassava crop free from weed interference and applying fertilizers. The presence of weeds during the first 100 days after planting reduced about 50% of the plant dry matter production in Ibarama and Santa Maria. Interestingly, it also affects 79.2% of fresh roots productivity in Ibarama.Os objetivos deste trabalho foram avaliar a resposta à adubação e diferentes épocas de controle de plantas daninhas no acúmulo de matéria seca de folhas, hastes, raízes e produção de massa fresca de raízes de mandioca. Dois experimentos foram conduzidos em campos comerciais nos municípios de Ibarama e Santa Maria localizados no Rio Grande do Sul, Sul do Brasil, durante a safra 2018/2019. Cinco tratamentos, com aplicações variadas de fertilizantes químicos e herbicidas foram utilizados para representar as práticas de manejo comumente utilizadas pelos agricultores do Sul do Brasil. O modelo baseado no processo Simanihot foi usado para simular o crescimento, desenvolvimento e produtividade da mandioca sob condições potenciais. Os resultados mostram que a dose recomendada de fertilizantes e calagem combinados com herbicida pré-emergente e três manejos mecânicos de limpeza de plantas daninhas apresentaram um aumento de 72% na produtividade de raízes em relação ao manejo utilizado pela produtividade média dos pequenos agricultores. Portanto, é possível atingir 80% do potencial de produtividade mantendo a cultura da mandioca livre de interferência de plantas daninhas e com aplicação de fertilizantes. A presença de plantas daninhas durante os primeiros 100 dias após o plantio reduziu cerca de 50% da produção de matéria seca da planta em Ibarama e Santa Maria e 79,2% da produtividade de raízes frescas em Ibarama

Estudo do impacto de diferentes índices associados ao El Niño oscilação sul na produtividade de soja no Rio Grande do Sul

The main factor associated with decreaes in soybean yield in Rio Grande do Sul is the irregular distribution of precipitation and the El Niño Southern Oscillation (ENSO) is the major responsible for the precipitation variability. The aim of this work was to analyze the relationship between climatic indicators associated with ENSO and soybean yield in the State. Series of soybean yield from 87 municipalities were evaluated between 1984 and 2013. These series were ordered in three groups of similar behavior (high, medium and low yield). The mean profiles of these groups were correlated with indices for Sea Surface Temperature anomalies in the Niño 3.4 region, the Southern Oscillation Index (SOI) and the Multivariate ENSO Index (MEI) with differents lags. SOI and MEI showed higher correlations with yield in periods of higher water requirement of the crop. El Niño episodes have beenassociated with increased yield and in situations of neutrality and La Niña, the influence of the phenomenon is less evident. In addition, the absence of a significant correlation in the time of preparation of the crop and in the beginning of the plantation evidences the necessity of including new indices in the discussions of agricultural planning in the State.O principal fator associado a queda de produtividade da soja no Rio Grande do Sul (RS) é a distribuição irregular da precipitação sendo o El Niño Oscilação Sul (ENOS) o maior responsável pela variabilidade na precipitação. O objetivo deste trabalho foi analisar a relação entre indicadores climáticos associados ao ENOS e a produtividade de soja no Estado. Foram avaliadas séries de produtividade de soja de 87 municípios entre 1984 e 2013. Estas séries foram ordenadas em três grupos de comportamento semelhante (alta, média e baixa produtividade). Os perfis médios destes grupos foram correlacionados com anomalias de Temperatura da Superfície do Mar na região do Niño 3.4, o Índice de Oscilação Sul (IOS) e o Multivariate ENSO Index (MEI) com diferentes defasagens. O IOS e o MEI apresentaram correlações mais elevadas com a produtividade em períodos de maior necessidade hídrica da cultura. Episódios de El Niño estiveram associados a elevação de produtividade e em situações de neutralidade e La Niña a influência do fenômeno é menos evidente. Além disso, a ausência de uma correlação significativa na época de preparação de safra e início do plantio evidencia a necessidade da inclusão de novos índices nas discussões de planejamento agrícola no Estado

A deriva de glyphosate interfere no desenvolvimento e produtividade de arroz irrigado

The objective of this research was to evaluate the injury to the development and yield of early cycle flooded rice cultivar (IRGA 430), caused by simulated glyphosate drift. The experiment was carried out in the field at the Experimental Station of the Rice - IRGA, in the 2016/17 season, and treatments were arranged in factorial scheme 3x2+1 whose factor A consisted of the glyphosate drift simulation with rates of 135; 270 and 540g ha-1 a.e.; the factor B of two nitrogen (N) rates, being 90 and 121.5 kg ha-1 N; more control without application of glyphosate and with the application of 90 kg ha-1 N. There increase in glyphosate rate results in higher injuries to the crop, with phytotoxicity symptoms, less panicles per area, and about 60% yield loss. The period of emergency until the anthesis (R4) was prolonged. The glyphosate simulated drift shows higher phytotoxicity, lesser plant height and increase development cycle, promoting negative interference on flooded rice yield.Objetivo do trabalho foi avaliar os danos ao desenvolvimento e produtividade de cultivar de arroz irrigado de ciclo precoce (IRGA 430), ocasionados por deriva simulada de glyphosate. O experimento foi realizado a campo na Estação Experimental do Arroz – IRGA na safra 2016/17 e os tratamentos foram arranjados em esquema fatorial 3x2+1 cujo fator A constou da simulação de deriva de glyphosate nas doses de 135; 270 e 540g ha-1 e.a.; o fator B de duas doses de nitrogênio (N), sendo eles 90 e 121,5 kg ha-1 de N; mais testemunha sem aplicação de glyphosate e com aplicação de 90kg ha-1 de N. O aumento na dose de glyphosate resultou em maiores danos à cultura, como sintomas de fitotoxicidade, redução no número de panículas por área e no rendimento de grãos que foi de aproximadamente 60% na maior dose estudada. De acordo com o aumento da dose de glyphosate também ocorreu o prolongamento no número de dias entre a emergência da cultura até o estágio de desenvolvimento de antese (R4). A deriva simulada de glyphosate evidencia que o herbicida causa elevada fitotoxicidade a cultura, menor estatura as plantas e aumento do ciclo de desenvolvimento, interferindo negativamente na produtividade da cultura do arroz irrigado

Uma atualização de novas cultivares de arroz irrigado por inundação no modelo SimulArroz

The objective of this work was to model, in the SimulArroz model, the three flood-irrigated rice (Oryza sativa) cultivars currently most grown in the state of Rio Grande do Sul, Brazil. The experiments to calibrate and validate the model were conducted in the municipalities of Cachoeirinha, Santa Maria, Uruguaiana, Santa Vitória do Palmar, and Cachoeira do Sul during four crop seasons. The number of leaves, phenology, aboveground dry matter biomass, and yield of each cultivar were evaluated. The results showed a slight overestimate of the R1, R4, and R9 stages; however, overall, the SimulArroz model had a good performance in simulating rice phenology for the three studied genotypes. Furthermore, the model had a reasonable accuracy in simulating aboveground dry matter and yield. The root-mean-square error (RMSE) for aboveground dry matter (leaves, stems, panicles, and grains) ranged from 0.5 to 3.0 Mg ha-1. For yield, the RMSE ranged from 0.8 to 1.3 Mg ha-1. The calibration of the SimulArroz model is efficient in simulating the growth, development, and grain yield of the most important flood-irrigated rice cultivars in Southern Brazil and can be used to estimate harvest forecast and yield potential, as well for yield gap studies.O objetivo deste trabalho foi modelar, no modelo SimulArroz, as três cultivares de arroz (Oryza sativa) irrigado atualmente mais cultivadas no Estado do Rio Grande do Sul. Os experimentos para calibrar e validar o modelo foram conduzidos nos municípios de Cachoeirinha, Santa Maria, Uruguaiana, Santa Vitória do Palmar e Cachoeira do Sul, durante quatro safras. Foram avaliados o número de folhas, a fenologia, a biomassa da matéria seca da parte aérea e a produtividade de cada cultivar. Os resultados mostraram uma leve superestimativa dos estádios R1, R4 e R9; no entanto, no geral, o modelo SimulArroz apresentou bom desempenho na simulação da fenologia do arroz para os três genótipos estudados. Além disso, o modelo teve uma precisão razoável em simular matéria seca da parte aérea e produtividade. A raiz quadrada do erro quadrático médio (RMSE) para matéria seca da parte aérea (folhas, caules, panículas e grãos) variou de 0,5 a 3,0 Mg ha-1. Para produtividade, a RMSE variou de 0,8 a 1,3 Mg ha-1. A calibração do modelo SimulArroz é eficiente em simular o crescimento, o desenvolvimento e a produtividade de grãos das cultivares de arroz irrigado mais importantes no Sul do Brasil e pode ser utilizada para estimar a previsão de safra e o potencial de produtividade, bem como para estudos de lacunas de produtividade

Densidade agronômica ótima de milho em ambientes subtropicais

The objective of this work was to determine the agronomic optimal plant density (AOPD) for corn (Zea mays) in environments with a high, medium, and low grain yield, as well as to define which yield component is the most sensitive to variations in plant density. On-farm experiments were conducted in the municipalities of Júlio de Castilhos, in the 2018/2019 growing season, and of Entre-Ijuís, Jóia, Agudo, and Júlio de Castilhos, in the 2019/2020 growing season, in the state of Rio Grande do Sul, Brazil. The production environments were classified as having a low ( 16 Mg ha-1) grain yield. Júlio de Castilhos was identified as a site of high yield; Jóia and Entre-Ijuís, as of medium yield; and Agudo, as of low yield. The AOPDs ranged from 60,000 to 140,000 plants per hectare in the different production environments. The AOPD was of 110,300 to 116,200 plants per hectare for the high-yield environment, 101,000 plants per hectare for the medium-yield environment, and 60,000 plants per hectare for the low-yield environment. The number of grains per row is the yield component that is the most sensitive to variations in plant density in all production environments.O objetivo deste trabalho foi determinar a densidade agronômica ótima de plantas (DAOP) para o milho (Zea mays), em ambientes de alta, média e baixa produtividade de grãos, bem como definir qual componente da produtividade é mais sensível às variações de densidade de plantas. Experimentos em fazenda foram conduzidos nos municípios de Júlio de Castilhos, na safra de 2018/2019, e de Entre-Ijuís, Jóia, Agudo e Júlio de Castilhos, na safra de 2019/2020, no estado do Rio Grande do Sul, Brasil. Os ambientes de produção foram classificados como de baixa ( 16 Mg ha-1) produtividade. Júlio de Castilhos foi identificado como ambiente de alta produtividade; Jóia e Entre-Ijuís, como de média produtividade; e Agudo, como de baixa produtividade. As DAOPs variaram de 60.000 a 140.000 plantas por hectare nos diferentes ambientes de produção. A DAOP foi de 110.300 a 116.200 plantas por hectare para o ambiente de alta produtividade, de 101.000 plantas por hectare para o ambiente de média produtividade e de 60.000 plantas por hectare para o ambiente de baixa produtividade. O número de grãos por fileira é o componente de rendimento mais sensível às variações de densidade de plantas, em todos os ambientes de produção

Sowing date and maturity group in soybean grown in lowlands

ABSTRACT It is projected an increase of about 30% in the world population by 2050 and a food demand increase by 60%, mainly vegetable proteins. Due to this, soybean is being introduced in new production systems, such as in rotation with irrigated rice in lowlands. Irrigated and non-irrigated experiments were conducted in order to determine the influence of irrigation on maturity groups, on yield components and yield in lowlands. Five soybean cultivars with maturity groups (MG) ranging from 4.8 to 7.8 were used, representing the cultivars sowing in southern Brazil, and three sowings were performed (October, November and January). A decrease in the number of pods m-2 was observed with the delay in the sowing date in both water regimes and MG, except MG 4.8 and 5.5, which had a higher number of pods m-2 when irrigated and sown in November. The leaf area index (LAI) was higher under the irrigated condition, for all MGs and sowing dates. The interaction between the yield components can be maximized by the combination of supplemental irrigation, anticipation of sowing date and the choice for cultivars with MG from 6.2 to 6.8 for lowland environments

Introdução da perda de produtividade de arroz pela competição com plantas daninhas no modelo SimulArroz

The objective of this work was to model weedy rice (Oryza sativa) and barnyard grass (Echinochloa spp.) competition with flood-irrigated rice, introducing it as a submodule into the SimulArroz model. The competition of both weeds with irrigated rice was modeled using the rectangular hyperbola equation. The “i” and “a” coefficients of the rectangular hyperbola for each of these weeds were obtained from the literature and from field experiments carried out in the state of Rio Grande do Sul, Brazil. In SimulArroz, yield loss was applied to penalize yield in all three technological levels (high, medium, and low) of physiological maturity. For weedy rice, the coefficient values of imean for the high, medium, and low technological levels were 1.04, 1.50, and 3.57 respectively, and, for barnyard grass, 4.70, 10.49, and 15.51 respectively. Coefficient “a” was 100 for weedy rice, and amean values for barnyard grass were 101.63, 104.92, and 96.88 for the high, medium, and low levels, respectively. The yield loss approach was suitable to model the competition of weedy rice and barnyard grass with irrigated rice. The submodule yield loss caused by the competition of weedy rice and barnyard grass with irrigated rice improves the predictive capacity of the SimulArroz model.O objetivo deste trabalho foi modelar a competição de arroz-daninho (Oryza sativa) e capim-arroz (Echinochloa spp.) com o arroz irrigado por inundação e introduzi-la como um submodelo no modelo SimulArroz. A competição das duas ervas daninhas com o arroz irrigado foi modelada com o uso da equação da hipérbole retangular. Os coeficientes “i” e “a” da hipérbole retangular referentes a cada erva foram obtidos na literatura e em experimentos de campo conduzidos no Rio Grande do Sul. No SimulArroz, a perda de produtividade foi aplicada para penalizar a produtividade nos três níveis tecnológicos (alto, médio e baixo) para maturidade fisiológica. Para o arroz-daninho, os valores do coeficiente imédio, para os níveis tecnológicos alto, médio e baixo, foram 1,04, 1,50 e 3,57, respectivamente, e, para o capim-arroz, foram 4,70, 10,49 e 15,51, respectivamente. O coeficiente “a” foi 100 para o arroz-daninho, e o amédio, para o capim-arroz, foi 101,63, 104,92, 96,88 para os níveis tecnológicos alto, médio e baixo, respectivamente. A abordagem de perda de produtividade foi adequada para modelar a competição de arroz-daninho e capim-arroz com o arroz irrigado. O submodelo de perda de produtividade pela competição de arroz-daninho e capim-arroz com o arroz irrigado melhora a capacidade preditiva do modelo SimulArroz