RESUMO A densidade de plantas e o espaçamento correto são fatores fundamentais para alcançar produtividade rentável e qualidade dos frutos em culturas agrícolas. Este estudo teve como objetivo avaliar a produtividade do tomateiro de crescimento determinado e as características físico-químicas dos frutos, em diferentes arranjos de plantio e densidades de plantas. Foram realizados dois experimentos, sendo que no primeiro experimento e no segundo experimento foram utilizados os híbridos CVR-2909 (CVR Plant Breeding) e HMX 7885 (Agristar), respectivamente. Os experimentos foram conduzidos em delineamento de blocos casualizados, com quatro repetições. Foram avaliados dez tratamentos em esquema fatorial duplo (2 × 5). No primeiro fator, foram avaliados dois arranjos de plantio: linhas simples e linhas duplas. No segundo fator, foram avaliadas cinco densidades de plantas: 15, 20, 25, 30 e 35 mil plantas ha-1. Para o híbrido CVR-2909, o cultivo em linhas simples proporcionou maior produtividade, já as maiores densidades de plantas resultaram em menor produção e número de frutos por planta. Para o híbrido HMX-7885, maiores densidades de plantas proporcionaram maior produtividade, porém com menor produção por planta, massa média e número de frutos por planta. Para esse híbrido o arranjo de plantio proporcionou maior taxa de frutos verdes. agrícolas físicoquímicas físico químicas CVR2909 CVR 2909 CVR-290 Breeding 788 Agristar, Agristar , (Agristar) respectivamente casualizados repetições 2 ( 5. 5 . 5) fator duplas 15 20 25 3 ha1. ha1 ha 1. 1 ha-1 CVR2909, 2909, planta HMX7885, HMX7885 7885, HMX-7885 verdes CVR290 290 CVR-29 78 (Agristar ha- HMX788 HMX-788 CVR29 29 CVR-2 7 HMX78 HMX-78 CVR2 CVR- HMX7 HMX-7 HMX-

ABSTRACT Plant density and correct row spacing are fundamental factors for achieving profitable yield and fruit quality in crops. This study aimed to evaluate the yield of tomato plants of determinate growth and the physicochemical characteristics of the fruits in different planting arrangements and plant densities. Two experiments were conducted using the hybrids CVR-2909 (CVR Plant Breeding) and HMX 7885 (Agristar) in the first and second experiments, respectively. The experiments were conducted in a randomized block design with four replicates. Ten treatments were evaluated in a double factorial scheme (2 × 5). Two planting arrangements were evaluated in the first factor: single and double rows. The second factor comprised five plant densities: 15, 20, 25, 30, and 35 thousand plants ha-1. For the CVR-2909 hybrid, single-row cultivation resulted in the highest yield, while higher planting densities gave the lowest yield and number of fruits per plant. For the HMX-7885 hybrid, it was found that higher densities gave higher yields but caused a decreasing effect on fruit production per plant, average fruit mass, and number of fruits per plant. For this hybrid, the planting arrangement provided a higher rate of green fruits. crops CVR2909 CVR 2909 CVR-290 Breeding 788 Agristar (Agristar respectively replicates 2 ( 5. 5 . 5) rows 15 20 25 30 3 ha1. ha1 ha 1. 1 ha-1 hybrid singlerow HMX7885 HMX-788 mass CVR290 290 CVR-29 78 ha- HMX788 HMX-78 CVR29 29 CVR-2 7 HMX78 HMX-7 CVR2 CVR- HMX7 HMX-

RESUMO O balanço hídrico é uma ferramenta com diversas aplicações na agricultura, incluindo a avaliação da adequação de um ambiente para o cultivo de uma determinada cultura, através da compreensão de como os recursos hídricos operam no sistema. Esta informação é vital para determinar se a água disponível satisfaz a necessidade da cultura. Assim, objetivou-se calcular o balanço hídrico em um Argissolo Vermelho-Amarelo para o cultivo de Coffea canephora no município de Cruzeiro do Sul, Acre, utilizando uma série histórica de 36 anos para avaliar o potencial e as restrições da cultura de acordo com a água disponível. Os resultados mostraram que, de forma geral, o cultivo de Coffea canephora é adequado para a região de estudo. Os períodos de déficit hídrico e de excesso de água são bem definidos, ocorrendo de abril a agosto e de setembro a março, respectivamente. Verificou-se que apenas a fase de floração do cafeeiro coincide com o período de déficit hídrico na região, exigindo assim irrigação para evitar comprometer essa etapa do desenvolvimento do fruto. Em relação ao Indice de Satisfação da Necessidade de Água (ISNA), observou-se que, quando calculado em uma escala mensal, indica baixo risco climático para o cultivo de Coffea canephora na região. No entanto, quando calculado em uma escala diária, o ISNA indica risco climático médio a alto para o cultivo durante vários períodos. O ISNA mostrou ser uma ferramenta adequada para a tomada de decisão quanto à adoção de técnicas de irrigação. agricultura sistema Assim objetivouse objetivou VermelhoAmarelo Vermelho Amarelo Sul Acre 3 geral estudo definidos março respectivamente Verificouse Verificou fruto ISNA, , (ISNA) observouse observou mensal entanto diária (ISNA

ABSTRACT Water balance is a tool that has various applications in agriculture, including assessing whether an environment is suitable for growing a specific crop by providing information on how water resources function in the system. This information is essential for determining whether the available water satisfies the crop’s demand. Thus, the objective of this work was to calculate the water balance of Typic Hapludults for growing coffee (Coffea canephora) crops in Cruzeiro do Sul, Acre, Brazil, using a 36-year historical series to assess the potential and limitation of the crop according to the water availability. The results showed that coffee crops are, in general, suitable for growing in the study region. Water deficit and water surplus periods are well-defined, from April to August and September to March, respectively. Flowering was the only stage of coffee crops that coincides with the water deficit period in the region; thus, irrigation is necessary to prevent compromising this stage and fruit development. The Water Requirement Satisfaction Index (WRSI), calculated on a monthly basis, indicates a low climate risk for coffee crops in the region. However, when calculated on a daily basis, the WRSI shows a medium to high climate risk for coffee crops in several periods. The WRSI proved to be an adequate tool for assisting in decision-making regarding the adoption of irrigation. agriculture system s demand Thus Coffea canephora Sul Acre Brazil 36year year 36 availability general region welldefined, welldefined well defined, defined well-defined March respectively thus development WRSI, , (WRSI) basis However decisionmaking decision making 3 (WRSI

RESUMO: O uso de métodos não destrutivos e de baixo custo para determinação de área foliar tem ganhado importantes aplicações. Os objetivos da pesquisa foram (i) propor um método não destrutivo para estimar a área foliar da cultura da mamona e (ii) construir equações que estimem com precisão e rapidez a área foliar da espécie. Foram coletadas mil folhas sadias e expandidas de cinco cultivares de mamona (New Zealand Purple, Sipeal, Carmencita, Amarelo de Irecê e IAC-80), sendo coletadas 200 folhas de cada uma. O comprimento máximo, largura máxima e área foliar foram calculados para cada folha. Foi calculado o produto entre comprimento e largura (LW). Foram realizados testes com diferentes modelos de regressão linear e não linear entre área foliar e dimensões lineares das folhas de cada cultivar. Os modelos utilizados foram linear, linear sem intercepto e potência. Os critérios para escolha dos melhores modelos para estimar a área foliar da mamona foram maior coeficiente de determinação, maior coeficiente de correlação linear de Pearson, menor critério de informação de Akaike, maior índice de concordância de Willmott e menor raiz do erro quadrático médio. As equações que apresentaram melhores critérios para estimativa da área foliar das cultivares de mamona foram aquelas que utilizaram o produto entre comprimento e largura, em comparação às equações que utilizaram apenas uma dimensão foliar. O modelo ŷ = 0,439 × LW pode ser utilizado para estimar com precisão e rapidez a área foliar da mamona por meio de medidas lineares das folhas, utilizando o produto entre comprimento e largura (LW), independente da cultivar escolhida. RESUMO aplicações i (i ii (ii espécie New Purple Sipeal Carmencita IAC80, IAC80 IAC 80 , IAC-80) 20 máximo folha LW. . (LW) potência Pearson Akaike médio 0439 0 439 0,43 LW, escolhida IAC8 8 IAC-80 2 (LW 043 43 0,4 IAC-8 04 4 0, IAC-

ABSTRACT: Using non-destructive and low-cost methods to determine leaf area has gained important applications. The research objectives were (i) to propose a non-destructive method to estimate the leaf area of castor bean crops and (ii) to build equations that accurately and quickly estimate the leaf area of specie. One thousand healthy and expanded leaves of five castor bean cultivars (New Zealand Purple, Sipeal, Carmencita, Amarelo de Irecê, and IAC-80) were collected, and 200 leaves were collected from each. The maximum length, maximum width, and leaf area were calculated for each leaf. The product between length and width (LW) were calculated. We performed tests with different linear and non-linear regression models between leaf area and linear leaf dimensions of each cultivar. The models used were linear, linear without intercept, and power. The criteria for choosing the best models to estimate the leaf area of castor beans were a higher coefficient of determination, more elevated Pearson’s linear correlation coefficient, lower Akaike information criterion, higher Willmott agreement index, and smallest root mean square error. The equations that presented the best criteria for estimating the leaf area of castor bean cultivars were those that used the product between length and width, compared to equations that used only one leaf dimension. The model ŷ = 0.439 × LW can be used to accurately and quickly estimate the castor bean leaf area through linear measurements of the leaves, using the product between length and width (LW), regardless of the cultivar chosen. ABSTRACT nondestructive non destructive lowcost low cost applications i (i ii (ii specie New Purple Sipeal Carmencita Irecê IAC80 IAC 80 IAC-80 20 (LW nonlinear intercept power determination Pearsons Pearson s criterion index error dimension 0439 0 439 0.43 LW, , chosen IAC8 8 IAC-8 2 043 43 0.4 IAC- 04 4 0.

ABSTRACT Cobalt (Co) and molybdenum (Mo) are essential elements with a fundamental role in biological nitrogen fixation in legumes. Vitamins such as thiamine, despite being required in small quantities, influence plant growth. This study aimed to assess the efficiency of different doses of thiamine applied as seed treatment, combined or not with Co and Mo, in enhancing the development of soybean crops. The experiment was conducted in a greenhouse according to a randomized block design with a 6 × 2 factorial arrangement, comprising six thiamine doses (0, 10, 25, 50, 100, and 200 mg kg-1) in the presence or absence of Co and Mo at the recommended rate of 100 mL ha-1. At 40 days after sowing, plants were analyzed for root length, root dry weight, shoot length, shoot dry weight, nodule number, and nodule dry weight. Principal component analysis showed that combined application of Co and Mo with thiamine was negatively associated with all variables and that the thiamine doses most positively associated with the analyzed variables were 50 and 200 mg kg-1. In treatments containing thiamine alone, there was a linear direct relationship between thiamine dose and nodule dry weight. Root and shoot lengths and dry weights were highest in plants treated with thiamine only at a dose of 122 mg kg-1. Application of Co and Mo combined with thiamine via seed treatment does not promote the development of soybean crops. Thiamine application is a promising treatment to increase shoot length, root dry weight, and nodule dry weight in soybean. (Co (Mo legumes quantities growth crops arrangement 0, 0 (0 10 25 20 kg1 kg 1 kg-1 ha1. ha1 ha 1. ha-1 4 sowing length number 5 kg1. alone 12 ( kg- ha-

Seeking a viable alternative to fossil fuels as the primary energy source, bioethanol has emerged as a promising second-generation fuel derived from lignocellulosic biomass. With Brazil ranking pineapple as the third most produced fruit in temporary crops, this study aims to assess the impact of chemical pretreatment techniques, specifically organosolv and diluted acid, on the residual biomass of Pérola pineapple peel to enhance bioethanol production. Employing an experimental design that incorporates temperature, reaction time, and varying concentrations of organic solvent, the study examines their effects on the susceptibility of the substrate to saccharification for future bioethanol generation. Factors such as alphacellulose, hemicellulose, and lignin were evaluated in triplicate and subjected to statistical analysis using the Tukey test with a confidence level of 95%. Upon application of the pretreatment methods, it was observed that the organosolv solvent approach (utilizing water and ethanol) with sulfuric acid exhibited superior sugar conversion, yielding the highest concentration of xylose at 9.13 g L-1. Additionally, the pretreated biomass contained 1.38 g L 1 of cellobiose, 3.11 g L-1 of arabinose, and 3.76 g L-1 of glucose. This technique demonstrates promising potential for obtaining fermentable sugars crucial for bioethanol production. source secondgeneration second generation crops techniques production temperature time alphacellulose hemicellulose 95 95% methods utilizing ethanol conversion 913 9 13 9.1 L1. L1 1. Additionally 138 38 1.3 cellobiose 311 3 11 3.1 L- arabinose 376 76 3.7 glucose 91 9. 31 3. 37 7

ABSTRACT The search for more sustainable systems of rice cultivation, especially in relation to water use, has included the evaluation of more-efficient irrigation systems in addition to alternative water sources. The aim of this study was to conduct a phytosociological survey of weeds in rice crops irrigated by subsurface drip with different concentrations of treated dairy effluent, maintaining the soil moisture at saturation or field capacity. A pilot scale experiment was carried out in a protected environment using a randomised block design in a 5 x 2 factorial scheme, with four replications. The IAC 301 cultivar (Arborio rice) was chosen. The phytosociological surveys were carried out on four different dates, and considered the composition as well as the distribution of plant species in each of the applied treatments, using the importance value index (IVI) to evaluate the influence of each treatment. The results showed that cultivating irrigated rice, giving priority to water management, altered the ecology of invasive plants. Fourteen weed species were identified, distributed over 10 families. The effluent dose did not alter the incidence of invasive plants, and only at the final evaluation was there a reduction in the IVI value at effluent concentrations of 50% and 75%. For soil moisture, the highest IVI values occurred on the first two days of the survey under saturated conditions; this result was reversed closer to plant maturity, when the IVI values were higher at field capacity. cultivation use moreefficient efficient sources capacity scheme replications 30 Arborio chosen dates treatments (IVI treatment management plants identified 1 families 50 75 75% conditions maturity 3 7

RESUMO Na agricultura irrigada, é comum a aplicação de água no solo cultivado sem critério, resultando em uso ineficiente ou não otimizado da água. Em muitos casos, a relação solo-água-planta, bem como as potencialidades e limitações dos sistemas de irrigação são ignoradas. A agricultura irrigada sustentável requer o desenvolvimento de um sistema de monitoramento da umidade do solo que evite a perda de água e melhore a eficiência do uso. O objetivo deste estudo foi desenvolver e avaliar a eficiência de um sistema inteligente de monitoramento da umidade do solo. O sistema é composto por duas estações: a primeira coleta os dados sobre parâmetros de umidade aparente do solo usando sensores, enquanto a segunda transmite esses dados para uma estação de processamento central. O sistema determina precisamente os valores atuais de umidade do solo, permitindo estimar o volume de água de irrigação necessário para atender à demanda hídrica da cultura com base na capacidade de campo. Os resultados da curva de calibração dos sensores indicam que o sistema pode medir com precisão a umidade do solo atual, auxiliando no manejo da irrigação. Para áreas irrigadas em condições de solo não saturado, recomenda-se o uso de tensiômetros devido à sua maior confiabilidade entre a capacidade de campo e o ponto de murcha permanente, garantindo práticas de irrigação mais precisas. critério casos soloáguaplanta, soloáguaplanta planta, planta solo-água-planta ignoradas estações central atual saturado recomendase recomenda se permanente precisas

ABSTRACT Water application to cultivated soil is often done without careful consideration in irrigated agriculture, leading to inefficient or suboptimal water usage. In many instances, the intricate relationship between soil, water, and plants, as well as the potential and limitations of irrigation systems, is overlooked. Sustainable irrigated agriculture necessitates the development of a soil moisture monitoring system that curtails water loss and enhances overall efficiency. This study aimed to develop and assess the efficiency of an intelligent system for monitoring soil moisture. The system comprises two stations: the first collects data on apparent soil moisture parameters using sensors, while the second transmits this data to a central processing station. The system precisely determines current soil moisture values, enabling estimation of the required irrigation water volume to meet the crop’s water demand based on field capacity. Results from the calibration curve of the sensors indicate that the system can measure current soil moisture precisely, aiding in irrigation management. For irrigated areas under unsaturated soil conditions, it is recommended to use tensiometers due to their higher reliability between field capacity and permanent wilting point, ensuring more accurate irrigation practices. usage instances plants systems overlooked stations station values crops crop s management conditions point practices

ABSTRACT The mechanized cutting of sugarcane requires improvements, as cutting tools can affect the longevity of sugarcane fields and increase production costs. Furthermore, these tools can increase the energy demand of machines in the field. This study evaluated the sugarcane harvester performance equipped with different basal cutting devices: impact cutting (blades) and continuous cutting (saws) in three commercial sugarcane production areas. The experimental design was completely randomized in a 3 × 2 factorial scheme with six repetitions. Effective fuel consumption and harvesting capacity were evaluated. The saws increased fuel consumption per area by 3.9 and 8.9% per Mg harvested. The crop’s yield characteristics determine harvesting systems’ energy demand. For yields above 90 Mg ha-1, energy demand has stabilized up to 120 Mg ha-1. The fuel demand for harvesting ranged between 1.0 and 1.2 L Mg-1 of harvested material. Regardless of the cutting system, each Mg requires 37.3 kJ of energy to be removed from the field. improvements costs Furthermore field devices blades (blades (saws areas repetitions 39 9 3. 89 8 8.9 crops crop s systems ha1, ha1 ha 1, 1 ha-1 12 ha1. 1. 10 0 Mg1 Mg- material system 373 37 37. 8. ha-

RESUMO O corte mecanizado da cana-de-açúcar necessita de aprimoramentos, visto que as ferramentas de corte podem afetar a longevidade dos canaviais e aumentar os custos de produção. Além disso, essas ferramentas podem aumentar a demanda energética das máquinas no campo. Este estudo avaliou o desempenho de colhedoras de cana-de-açúcar equipadas com distintos mecanismos de corte basal: corte por impacto (lâminas) e corte contínuo (serras) em três áreas comerciais de produção de cana-de-açúcar. O consumo efetivo de combustível e a capacidade efetiva de colheita das máquinas foram avaliados em cada tratamento. O delineamento experimental adotado foi inteiramente casualizado em esquema fatorial 3 × 2 com seis repetições. As serras aumentaram o consumo de combustível por área em 3,9 e 8,9% por Mg colhido. As características produtivas da cultura determinam a demanda energética dos sistemas de colheita. Para produtividades acima de 90 Mg ha-1, a demanda energética estabilizou-se até 120 Mg ha-1. A demanda de combustível para a colheita variou entre 1,0 e 1,2 L Mg-1 de material colhido. Os resultados mostram que independente do sistema de corte, cada Mg de cana colhida necessita em média de 37,3 kJ de energia para ser retirado do campo. canadeaçúcar açúcar aprimoramentos disso campo basal lâminas (lâminas (serras canadeaçúcar. açúcar. tratamento repetições 39 9 3, 89 8 8,9 colhido ha1, ha1 ha 1, 1 ha-1 estabilizouse estabilizou se 12 ha1. 1. 10 0 Mg1 Mg- 373 37 37, 8, ha-

ABSTRACT In regions with water shortages, detailed planning on water resource use is essential. The use of climate models for short- and medium-range forecasts is an important strategy for obtaining early information on the water requirements of crops and the water regime of a particular basin. This study aimed to assess the performance of seasonal climate forecasts and their applicability in estimating irrigation needs. To that end, the Simulation Model for Irrigation Strategies and climate forecast data derived from the Eta model were used. To analyze simulations, five members (days 13, 14, 15, 16 and 17) of the seasonal forecasts of rainfall and reference evapotranspiration for every month between 2001 and 2012 were used. The spread for reference evapotranspiration demonstrated that the model was unable to reproduce the behavior of this variable during the dry period. Comparison between forecasts months in advance showed no significant differences between the rainfall and the reference evapotranspiration forecasts. However, the results obtained for a one-month lead-time forecast exhibited superior performance. shortages essential short mediumrange medium range basin needs end used simulations days 13 14 15 1 17 200 201 period However onemonth one leadtime lead time 20 2

RESUMO Em regiões com baixa disponibilidade hídrica é de grande importância um planejamento mais detalhado sobre o uso de recursos hídricos. A utilização de modelos climáticos destinados às previsões de curto e médio prazo se apresenta como uma estratégia importante para se obter informações antecipadas acerca da demanda hídrica de culturas e do regime hídrico de determinada bacia. Objetivou-se, neste estudo, avaliar o desempenho das previsões climáticas sazonais e sua aplicabilidade na estimativa da demanda de irrigação. Para tanto, utilizou-se o Modelo de Simulação de Estratégias de Irrigação e dados de previsão climática derivados do modelo Eta. Para análise das simulações, foi utilizado um conjunto de cinco membros (dias 13, 14, 15, 16 e 17) de previsão sazonal de precipitação e evapotranspiração de referência para cada mês entre o período de 2001 a 2012. O espalhamento para a evapotranspiração de referência demonstrou que o modelo não foi capaz de reproduzir o comportamento desta variável durante o período seco. Comparação entre previsões com os meses de antecedência não demonstraram diferenças significativas entre previsões da precipitação e da evapotranspiração de referência. Contudo, os resultados obtidos para as previsões com um mês de antecedência apresentaram melhor desempenho. hídricos bacia Objetivouse, Objetivouse Objetivou se, Objetivou-se estudo irrigação tanto utilizouse utilizou Eta simulações dias 13 14 15 1 17 200 2012 seco Contudo 20 201 2

ABSTRACT Traditional agroecosystems (TA) are considered more resilient to climatic extremes due to higher crop diversity and agroecological approach. The TA of Tének were studied to evaluate their drought tolerance. Open-ended questionnaire surveys, field visits, and botanical collections, with the participation of local farmers, were considered. Cultivated plant diversity was analyzed using the Shannon-Wiener diversity index (H’), and the Morisita-Horn index (CMH) in ten different agroecosystems in April and August. Remote sensing methods included the triangular greenness index (TGI). Additionally, normalized difference vegetation index (NDVI) and standardized precipitation index (SPI) were determined, covering the period from 2013 to 2022. The cultivated plant richness (P > 0.5382) and their abundance (P > 0.3622) did not change from April to August considering the total analyzed parcels. However, differences between types of agroecosystems were observed because higher diversity corresponded to managed jungle (teʼlom) (Hʼ = 1.5-1.7), and some parcels cultivated with maize (milpa) (Hʼ = 1.02-1.54). Nevertheless, in August, lower similarity was observed in milpa (CMH = 0.23-0.87) due to the absence of maize (Zea mays L.) and other herbaceous annual crops. Landscape interconnection can be affirmed with TGI correlations obtained by comparison of different TA. The negative SPI values were associated with a decrease of NDVI, but Tének polyculture agroecosystems maintained higher NDVI values compared to rainfed monocropping during the analyzed period. Tének polyculture agroecosystems exhibited higher drought tolerance, although maize and other herbaceous plants are susceptible to disappearing during prolonged drought events, thereby increasing food insecurity.

Abstract Rural roads serve as pivotal conduits for the transportation of harvested crops to distribution hubs in Guarapuava-PR, a national agricultural focal point. This study evaluated the impact of incorporating brick kilns ashes(BKA) into the lateritic soil of an unpaved roadway. Mixtures of soil and BKA with three distinct granulometries were formulated, featuring substitution rates of 25%, 50%, and 75% ash relative to the total mixture mass,characterized in terms of: particle size distribution, liquid limit (LL), plastic limit (PL), and the optimum point on the compaction curve under modified energy conditions (optimal moisture content and maximum dry bulk density). Results revealed that BKA inclusion led to increases in LL, PL, OMC, CBR, alongside a reduction of MDD and expansion for the majority of mixtures, particularly within granulometry C1 at a 25% content. Finer ashes exhibited prominence in ISC and expansion outcomes. Substitutions of 75% BKA detrimentally affected geotechnical properties; however, granulometric stabilization with BKA proved feasible, particularly in soil-C2 mixtures designated for use as a sub-base. These mixtures met recommended LL and PL parameters, providing effective waste mitigation and presenting an alternative for soil improvement in pavement applications. GuarapuavaPR, GuarapuavaPR Guarapuava PR, PR Guarapuava-PR ashesBKA ashes(BKA roadway formulated 25 50 50% 75 masscharacterized mass characterized , (LL) (PL) optimal density. density . density) OMC CBR C outcomes properties however feasible soilC2 soilC C2 soil-C subbase. subbase sub base. base sub-base parameters applications 2 5 7 (LL (PL

Resumo Estradas vicinais são muito utilizadas para o escoamento da safra da área da colheita até os centros de distribuição na cidade de Guarapuava-PR, referência nacional no setor agrícola. Esta pesquisa avaliou o efeito da adição de cinzas de fornos de olarias (CFO) ao solo laterítico de uma estrada não pavimentada. Foram produzidas misturas de solo e CFO de três diferentes granulometrias, nos teores de substituição de 25%, 50% e 75%, de cinza em relação à massa total da mistura, caracterizadas quanto à:granulometria, limite de liquidez (LL), limite de plasticidade (LP) e ponto ótimo da curva de compactação sob energia modificada (umidade ótima (wot) e peso específico aparente seco máximo (ρdmáx)). Os resultados obtidos mostraram que a adição da CFO foi responsável por aumentos nos parâmetros LL, LP, wot, ISC, bem como pela redução do ρdmáx e da expansão da maioria das misturas, principalmente para a granulometria C1, no teor de 25%. Cinzas mais finas destacaram-se nos resultados de ISC e expansão. Substituições de 75% de CFO prejudicaram as propriedades geotécnicas, mas a estabilização granulométrica com CFO revelou-se viável, especialmente em misturas solo-C2 para utilização como sub-base, atendendo aos parâmetros recomendados de LL e LP, proporcionando mitigação de resíduos e uma alternativa para melhoramento de solos para pavimentação. GuarapuavaPR, GuarapuavaPR Guarapuava PR, PR Guarapuava-PR agrícola (CFO pavimentada granulometrias 25 25% 50 75 mistura àgranulometria, àgranulometria granulometria, à:granulometria , (LL) LP (LP umidade wot (wot ρdmáx. . (ρdmáx)) C1 C destacaramse destacaram se geotécnicas revelouse revelou viável soloC2 soloC C2 solo-C subbase, subbase sub base, base sub-base pavimentação 2 5 7 (LL (ρdmáx) (ρdmáx

Abstract Introduction. Weeds are one of the main problems in agricultural productivity due to their interactions with crops, such as alelopatic effects on germination. Objective. To evaluate the allelopathy of kikuyo grass (Cenchrus clandestinus) on the germination of beans (Phaseolus vulgaris L.) variety ICA Cerinza. Materials and methods. The study was conducted at the Quality Control Laboratory of the Universidad de Pamplona, Central Campus, Pamplona, Norte de Santander, Colombia, from May to August 2022. To each experimental unit (Petri dishe) with 12 been seeds, 6 mL of kikuyo aqueous extract (leaf, stem, and root) at three concentrations (1, 2.5, and 5 %), plus a control (0 %), were added, totaling 12 treatments. From day 0 to 12, the number of germinated seeds (NGS) was recorded, and the germination rate index (GRI) and germination index (IG) were calculated. The biomolecular profile of the aqueous extract was determined using the Fourier-transform spectroscopy. A completely randomized experimental design with a factorial arrangement (3x4), with repeated measures in each experimental unit, was employed. The intersuject factors were the organ type and concentration, while the intrasubject factor was the evaluation time (12 days). Results. Significant differences (p<0.001) were observed for NSG among treatments due to the concentration of the aqueous extract, as well as for IG, while GRI depended on the organ (p<0.05) and concentration (p<0.001), both negatively affected as the concentration increased. The infrared spectrum of the extract determined the presence of polyphenols, nitriles, and siloxanes. Conclusión. C. clandestinus affected NGS, GRI, and GI of P. vulgaris, with an allelopathic effect of the leaf aqueous extract at higher concentrations. Polyphenols, nitriles, and siloxanes associated with allelopathic effects were identified in the aqueous extracts.

Resumen Introducción. Las arvenses son uno de los principales problemas en la productividad agrícola, debido a interacciones con el cultivo, como efectos alelopáticos sobre la germinación. Objetivo. Evaluar la alelopatía del pasto kikuyo (Cenchrus clandestinus) en la germinación de frijol (Phaseolus vulgaris L.) variedad ICA Cerinza. Materiales y métodos. El estudio se realizó en el laboratorio de Control de Calidad de la Universidad de Pamplona, Campus Central, Pamplona, Norte de Santander, Colombia, en mayo-agosto 2022. A cada unidad experimental (caja de Petri) con doce semillas de frijol se le agregó 6 mL de extracto acuoso de kikuyo (hoja, tallo y raíz) en tres concentraciones (1, 2,5 y 5 %), más un testigo (0 %), para un total de doce tratamientos. En el lapso de 0 a 12 días, se registró el número de semillas germinadas (NSG), se calculó el índice de tasa de germinación (ITG) y el índice de germinación (IG), y se determinó el perfil biomolecular del extracto acuoso mediante la técnica de espectroscopia transformada de Fourier. Se utilizó un diseño experimental completamente al azar con arreglo factorial (3x4), con medidas repetidas en cada unidad experimental. Los factores intersujetos fueron el tipo de órgano y concentración, y el factor intrasujeto fue el tiempo (12 días) de evaluación. Resultados. Se observaron diferencias significativas (p<0,001) para NSG entre tratamientos por efecto de la concentración del extracto acuoso al igual que para IG, mientras que ITG dependió del órgano (p<0,05) y la concentración (p<0,001); ambos fueron afectados de forma negativa conforme aumentó la concentración. En el espectro infrarrojo del extracto se determinaron polifenoles, nitrilos y siloxanos. Conclusión. C. clandestinus afectó NSG, el ITG e IG de P. vulgaris, con efecto alelopático del extracto acuoso de hoja en mayor concentración. En los extractos acuosos se determinaron polifenoles, nitrilos y siloxanos, asociados a efecto alelopático.

Abstract Introduction. The main control measure for brown spot (BS) caused by Septoria glycines is through the application of foliar fungicide. However, the management of the disease could be accomplished through cultural and genetic practices. Objective. To analyze the evolution of BS in soybean under different production systems. Materials and methods. This study was conducted for two consecutive years (2020 and 2022), in Pergamino, Buenos Aires, using the soybean cultivar DM46i20. The management variables studied were cover crops (CC), rotations (Rt), and timing of foliar fungicide application (MAFF). The evaluated pathometric variable was the area under the progress curve of plant height with symptoms (ABCPAPS), and the quantitative physiology variable was grain yield (R) in kg/ha. Results. Agronomic management practices had a significant effect (p≤0.05) on R and ABCPAPS. CC and MAFF were independent variables and showed a significant response (p<0.0001) on R. On the other hand, there was a significant triple interaction (p<0.0001) among CC, Rt, and MAFF for ABCPAPS, and therefore, the data were explained based on this relationship. Conclusions. The implementation of cover crops, crop rotations, and foliar fungicide significantly reduced (p≤0.05) the evolution of BS in soybean cultivation. There was a significant negative correlation (p≤0.05) between soybean yield and the area under the progress curve of the plant height with BS symptoms.

Resumen Introducción. La principal medida de control de la mancha marrón (MM) causada por Septoria glycines, se realiza mediante la aplicación de fungicida foliar, sin embargo, el manejo de la enfermedad podría realizarse con prácticas de manejo cultural y genético. Objetivo. Analizar la evolución de la MM de la soja en diferentes sistemas de producción. Materiales y métodos. Este estudio se llevó a cabo durante dos años consecutivos (2020 y 2022), en la localidad de Pergamino, Buenos Aires, sobre un cultivar de soja DM46i20. Las variables de manejo fueron cultivos de cobertura (CC), rotaciones (Rt), momento de aplicación del fungicida foliar (MAFF). La variable patométrica evaluada fue el área bajo la curva de progreso de la altura de la planta con síntomas (ABCPAPS) y como variable cuantitativa fisiología sobre el cultivo el rendimiento (R) en granos en kg/ha. Resultados. Las prácticas de manejo agronómico tuvieron un efecto significativo (p≤0,05) sobre el R y el ABCPAPS. Las variables CC y MAFF fueron independientes y presentaron una repuesta significativa (p<0,0001) sobre el R. En cambio, hubo una triple interacción significativa (p<0,0001) entre los CC, las Rt y el MAFF para el ABCPAPS y, por lo tanto, los datos fueron explicados con base en esta relación. Conclusiones. La implementación de cultivos de cobertura, de rotaciones de cultivo y de fungicida foliar, redujeron significativamente (p≤0,05) la evolución de la MM en el cultivo de soja. Hubo una correlación negativa y significativa (p≤0,05) entre el rendimiento en soja y el área bajo la curva de progreso de la altura de la planta con síntomas de la MM.

Abstract Introduction. Pesticides are used to control pests and diseases in agricultural activities. Improper management of these products poses a potential risk to human health and the environment. Objective. To evaluate the (eco)toxicological pressure exerted by synthetic pesticides on tobacco crops (Nicotiana tabacum) in the province of Sancti Spíritus, Cuba. Materials and methods. A database from the Provincial Directorate of Plant Health for the period 2016-2019 was used, where the pesticides assigned to the province for this crop were compared with those reported by interviewed farmers. The dual indicator POCER was used to obtain the results, determining the pressure exerted by different pesticides and their harmful reference on humans and the environment. Results. The trend in pesticide consumption (summarized in tables and graphs) showed 50 % decrease, corresponding to the country’s crop protection policy. Farmers mentioned the use of authorized and unauthorized active ingredients in the conducted surveys, and sixteen high-risk active ingredients were detected in the analyzed samples. Evaluating the POCER results and analyzed samples, a significant (eco)toxicological pressure was observed on both the environment and human health, exerted by a group of high-toxicity active ingredients used in tobacco cultivation in the province. Conclusion. Using the dual indicator POCER provides an evaluation of the (eco)toxicological pressure exerted by synthetic pesticides used in the tobacco cultivation (Nicotiana tabacum) in the province of Sancti Spíritus, Cuba, for the study period.

Resumen Introducción. Los plaguicidas son utilizados para controlar las plagas y enfermedades en las actividades agrícolas. El manejo inadecuado de estos productos constituye un riesgo potencial para la salud humana y el medio ambiente. Objetivo. Evaluar la presión toxicológica (eco) ejercida por los plaguicidas sintéticos en los cultivos de tabaco (Nicotiana tabacum) en la provincia de Sancti Spíritus, Cuba. Materiales y métodos. Se utilizó una base de datos de la Dirección Provincial de Sanidad Vegetal para el período 2016-2019, donde se tomaron los plaguicidas asignados a la provincia para este cultivo y se compararon con los declarados por los agricultores entrevistados. Para la obtención de los resultados se utilizó el indicador dual POCER, que determinó la presión ejercida por los diferentes plaguicidas y su referencia nociva sobre el ser humano y el medio ambiente. Resultados. La tendencia del consumo de plaguicidas (resumida en tablas y gráficos) mostró una disminución del 50 %, que corresponde a la política de protección de los cultivos del país. Los agricultores mencionaron el uso de ingredientes activos autorizados y no autorizados en las encuestas realizadas, y en las muestras analizadas se detectaron dieciséis ingredientes activos de alto riesgo. Al evaluar los resultados de POCER y muestras analizadas se observó que existe una gran presión (eco)toxicológica tanto para el medio ambiente como para la salud humana ejercida por un grupo de ingredientes activos de alta toxicidad utilizados en el cultivo de tabaco de la provincia. Conclusión. Con la utilización del indicador dual POCER, se obtiene una evaluación de la presión (eco)toxicológica ejercida por los plaguicidas sintéticos utilizados en el cultivo del tabaco (Nicotiana tabacum) en la provincia de Sancti Spíritus, Cuba para el período de estudio.

Abstract Introduction. The soil and climatic conditions of Ecuador are ideal for rice cultivation, yields are higher than the world average, but agronomic management leads to an increase of cadmium in the soil, which can reach the grain by translocation, which affects its safety. Objetive. To evaluate the absorption of cadmium through the omission of macronutrients technique in six soils of Ecuador and its effect on the vegetative development of rice crops. Materials and methods. The trial was carried out at the Pichilingue Tropical Experimental Station of the National Institute of Agricultural Research, Ecuador, during 2018. Nine treatments were studied: 1) Without fertilization and without Cd (control 1), 2) without fertilization and with Cd (Control 2), 3) Complete fertilization and six omission treatments of one nutrient at a time, a completely randomized block design of experiments, divided plots and three repetitions was used. The variables evaluated were those related to the production of dry matter in the root and aerial part. For the comparison between means, the Tukey test was used (p<0.05). Results. Nutrients omissions (N and P) led to reduced Cd absorption, which decreased dry matter production, particularly in very acidic or alkaline soils such as in Sucumbíos (pH 4) and Guayas (pH 7, 9), respectively. Conclusions. The absorption of cadmium in rice plants was reduced to a greater extent with the omission of the macronutrients N and P, mainly in the soils of Sucumbíos, Los Ríos, El Oro and Manabí, the nutrient omission technique also affecting the production of dry matter and yields, also observing that a pH below 5 or higher than 7.9 affects the absorption of cadmium in the soils studied.

Resumen Introducción. Las condiciones edafoclimáticas del Ecuador son ideales para el cultivo del arroz, los rendimientos son mayores al promedio mundial, pero su manejo agronómico conlleva a un aumento de cadmio en el suelo, que puede llegar al grano por translocación, lo cual afectan su inocuidad. Objetivo. Evaluar la absorción de cadmio mediante la técnica de omisión de macronutrientes en seis suelos del Ecuador y su efecto sobre el desarrollo vegetativo del cultivo de arroz. Materiales y métodos. El ensayo se realizó en la Estación Experimental Tropical Pichilingue del Instituto Nacional de Investigaciones Agropecuarias, Ecuador, durante el año 2018. Se estudiaron nueve tratamientos 1) Sin fertilización y sin Cd (testigo 1), 2) sin fertilización y con Cd (Testigo 2), 3) Fertilización completa y seis tratamientos de omisión de un nutriente a la vez, se usó un diseño de experimentos de bloques completamente al azar, parcelas divididas y tres repeticiones. Las variables evaluadas fueron las relacionadas a la producción de materia seca en raíz y parte aérea. Para la comparación entre medias, se utilizó la prueba de Tukey (p<0,05). Resultados. Las omisiones de los nutrientes (N y P) llevaron a la reducción de la absorción del Cd, que disminuyó la producción de materia seca, en particular en los suelos muy ácidos o alcalinos como en Sucumbíos (pH 4) y Guayas (pH 7,9), respectivamente. Conclusiones. La absorción de cadmio en plantas de arroz se redujo en mayor medida con la omisión de los macronutrientes N y P, principalmente en los suelos de Sucumbíos, Los Ríos, El Oro y Manabí, afectando también la omisión de nutrientes a la producción de materia seca y los rendimientos, observándose además que un pH por debajo de 5 o superior a 7,9 afecta la absorción de cadmio en los suelos estudiados