ABSTRACT The estimation of evapotranspiration (ET) and crop water requirements are crucial for the proper management and allocation of water resources in terms of quantity, quality, and timeliness. Therefore, remote sensing estimation of ET using the SEBAL algorithm (Surface Energy Balance Algorithm for Land) can provide spatio-temporal, non-punctual data, unlike traditional calculations relying on the nearest meteorological station. This research analyzed ET using SEBAL, based on ten Landsat 8 satellite images processed with a program developed in the Model Builder of ArcGis® version 10.2. The analysis was conducted during the vegetative period of starchy corn from May to October 2016. Validation of the results happened with a drainage lysimeter installed in a monitoring plot. Additionally, the statistical indices - such as percentage relative error (PRE) (0,09), root mean square error (RMSE) (0,30), R2 (0,92), and Nash-Sutcliffe efficiency (NASH) (0,91) - indicated a good correlation of ET for starchy corn in the central highlands of Peru. The ET identified at ten monitoring points ranged from 1,05 to 7,79 mm d-1. (ET quantity quality timeliness Therefore Surface Land spatiotemporal, spatiotemporal spatio temporal, temporal spatio-temporal nonpunctual non punctual data station ArcGis 102 10 2 10.2 2016 plot Additionally PRE (PRE 0,09, 009 0,09 , 0 09 (0,09) RMSE (RMSE 0,30, 030 0,30 30 (0,30) R 0,92, 092 0,92 92 (0,92) NashSutcliffe Nash Sutcliffe NASH (NASH 0,91 091 91 (0,91 Peru 105 1 05 1,0 779 7 79 7,7 d1. d1 d 1. d-1 10. 201 00 0,0 (0,09 03 0,3 3 (0,30 0,9 9 (0,92 (0,9 1, 77 7, d- 20 0, (0,0 (0,3 (0, (0 (

RESUMO Os modelos de balanço hídrico do solo podem ser uma boa opção para estudar o crescimento das culturas e as respostas de rendimento sob diferentes níveis de fornecimento de água. O objetivo deste estudo foi avaliar os efeitos de diferentes estratégias de irrigação na produtividade do girassol e na produtividade da água usando experimentos de campo e simulações de balanço hídrico do solo. Dois experimentos de campo foram realizados. Em 2018/19, foram utilizadas quatro estratégias de irrigação (mantida a água disponível no solo em 80, 70, 60 e 50% da água total disponível). Em 2020/21 foi utilizado um tratamento irrigado e de sequeiro. O modelo SIMDualKc foi calibrado e validado para simular o balanço hídrico do solo e derivar os coeficientes duais usando variáveis da planta a partir de observações de campo. A produtividade de grãos foi maior no tratamento mantido a 70% do total de água disponível no Estudo I, sugerindo que a redução da reposição de água pode ser uma alternativa para o manejo da irrigação, principalmente em locais onde a água é escassa. Os indicadores estatísticos mostraram um bom desempenho do modelo na simulação da água disponível no solo, com coeficiente de determinação > 0,90 e eficiência de modelagem acima de 0,86 para todos os casos. O estudo permitiu a calibração do coeficiente de cultura simples e basal do girassol, que são parâmetros importantes para o manejo da irrigação. realizados 201819 2018 19 2018/19 mantida 80 70 6 50 disponível. . disponível) 202021 2020 21 2020/2 sequeiro I escassa 090 0 90 0,9 086 86 0,8 casos 20181 201 1 2018/1 8 7 5 20202 202 2 2020/ 09 9 0, 08 20 2018/

ABSTRACT Soil water balance models can be a good option for studying crop growth and yield responses under different water supply levels. The aim of this study was to evaluate the effect of different irrigation strategies on sunflower yield and water productivity using field experiments and soil water balance simulations. Two field experiments were performed. In 2018/19, four irrigation strategies (aimed at maintaining soil available water at 80, 70, 60, and 50% of total available water) were evaluated. In 2020/21 an irrigated and a rain-fed treatment were evaluated. The SIMDualKc model was calibrated and validated to simulate soil water balance and derive the dual coefficients using plant variables from field observations. Grain yield was highest in the treatment maintained at 70% of total available water in Study I, suggesting that a water replenishment reduction strategy may be an alternative to irrigation management, especially in locations where water is scarce. The statistical indicators showed good performance of the model in simulating the water available in the soil, with the coefficient of determination > 0.90 and modeling efficiency above 0.86 for all cases. The study allowed the calibration of the single and basal crop coefficients of sunflower, which are important parameters for irrigation management. levels simulations performed 201819 2018 19 2018/19 aimed 80 70 60 50 evaluated 202021 2020 21 2020/2 rainfed rain fed observations I management scarce 090 0 90 0.9 086 86 0.8 cases 20181 201 1 2018/1 8 7 6 5 20202 202 2 2020/ 09 9 0. 08 20 2018/

RESUMO A cultura do sorgo é considerada uma das mais importantes do mundo devido a sua versatilidade de utilização. No entanto, o estresse hídrico pode ser considerado uma ameaça significativa para sua produtividade. A busca por produtos mitigadores do estresse hídrico é uma área de pesquisa crucial na agricultura e na gestão de recursos hídricos. Assim, o objetivo deste trabalho foi avaliar a viabilidade do uso do ácido salicílico como atenuante de estresse hídrico na cultura do sorgo. O experimento foi conduzido em ambiente telado, em delineamento em blocos ao acaso com esquema fatorial 4 × 2, com quatro repetições. Foram avaliados quatro níveis hídricos (40, 60, 80 e 100% da evapotranspiração) e duas concentrações de ácido salicílico (0 e 2,76 g L-1). Foram analisados a altura das plantas, diâmetro do caule, número de folhas, trocas gasosas, pigmentos fotossintéticos e fluorescência da clorofila a. A aplicação de lâminas de irrigação deficitárias reduziu a altura da planta, diâmetro do colmo, número de folhas e clorofila total no sorgo. No entanto, quando essas lâminas foram associadas ao ácido salicílico, foi observado que houve atenuação dos danos, especialmente em relação a clorofila a e b. Além disso, o ácido salicílico quando aplicado isoladamente, contribuiu para redução da temperatura da folha e aumento da eficiência de uso da água. Assim, o ácido salicílico pode ser usado para mitigar os efeitos do estresse salino em plantas de sorgo. utilização entanto produtividade Assim telado 2 repetições 40, 40 (40 60 8 100 evapotranspiração 0 ( 276 76 2,7 L1. L1 L 1 . L-1) caule gasosas planta colmo danos b disso isoladamente água (4 6 10 27 7 L-1 L-

ABSTRACT The sorghum crop is considered one of the most important worldwide due to its versatility. However, water stress can be considered a significant threat to its yield. The search for products that mitigate water stress is a crucial area of research in agriculture and water resources management. Thus, the objective in this study was to evaluate the feasibility of using salicylic acid as a water stress attenuator in sorghum. The experiment was conducted in a screened environment in a randomized block design with a 4 × 2 factorial scheme, with four replicates. Four levels of water (40, 60, 80, and 100% of evapotranspiration) and two concentrations of salicylic acid (0 and 2.76 g L-1) were evaluated. Plant height, stem diameter, number of leaves, gas exchange, photosynthetic pigments, and chlorophyll a fluorescence were analyzed. Application of deficit irrigation depths reduced plant height, stem diameter, number of leaves, and total chlorophyll in sorghum. However, when these depths were associated with salicylic acid, it was observed that the damage was attenuated, especially in chlorophyll a and b. Furthermore, salicylic acid reduced leaf temperature and increased water use efficiency when applied alone. Thus, salicylic acid can be used to mitigate the effects of salt stress on sorghum plants. versatility However yield management Thus scheme replicates 40, 40 (40 60 80 100 evapotranspiration 0 ( 276 76 2.7 L1 L 1 L-1 evaluated height diameter leaves exchange pigments analyzed attenuated b Furthermore alone plants (4 6 8 10 27 7 2. L-

Abstract Introduction. Estimating crop evapotranspiration (ETc) helps determine water requirements, enabling the proposal of irrigation techniques that save water. Objective. To use remotely piloted aircraft system (RPAs) for greater precision in measuring evapotranspiration in rice fields, aiming to reduce water consumption. Materials and methods. The study utilized a randomized complete block design with a factorial structure of two experiments: flooded irrigation (E1) and irrigation with controlled drying (E2), and three rice varieties (IR43, IR71706, Sahod Ulan 12). The study was conducted at the Experimental Irrigation Area (AER) of the Universidad Nacional Agraria La Molina, Peru. Eight RPAS flights were carried out between January and February 2019, distributed between the tillering and cotton point stages. Results. The combined analysis of treatments using analysis of variance (ANOVA) and Duncan’s test with p < 0.05 revealed a significant difference in ETc between E1 and E2. However, no significant difference was found between the rice varieties. Maximum values of ETc and yield were obtained for E1 at 4.50 mm/day and 10389 kg/ha, and for E2 at 3.7 mm/day and 9710 kg/ha, respectively. Conclusions. The use of a remotely piloted aircraft system improved the temporal and spatial resolution of multispectral and thermal images, providing greater accuracy in crop evapotranspiration (ETc) under two irrigation regimes. Controlled drying irrigation resulted in a A 24% reduction in ETc, allowing for a water saving of 855 m3/ha.

Resumen Introducción. La estimación de la evapotranspiración del cultivo (ETc) permite conocer los requerimientos de agua del cultivo, que ayudan a proponer técnicas de riego con ahorro de agua. Objetivo. Usar el sistema de aeronave pilotada remotamente (RPAs) para mayor precisión de la evapotranspiración en arrozales a fin de reducir el consumo de agua. Materiales y métodos. Para el estudio la distribución de parcelas siguió un diseño de bloques completamente al azar con estructura factorial de dos experimentos: riego inundado (E1) y riego con secas controladas (E2), y tres variedades de arroz (IR43, IR71706, Sahod Ulan 12); se llevó a cabo en el Área Experimental de Riego (AER) de la Universidad Nacional Agraria La Molina, Perú. Entre enero y febrero del 2019 se realizaron ocho vuelos, de un RPAs, distribuidos entre las etapas de macollamiento y punto de algodón. Resultados. El análisis combinado de tratamientos con análisis de varianza y prueba de Duncan con p < 0,05, reveló diferencia significativa de la ETc, entre E1 y E2. Sin embargo, no se encontró diferencia significancia entre las variedades de arroz. Se obtuvo valores máximos de ETc y rendimiento para E1 de 4,50 mm/d y 10 389 kg/ha, y para E2 de 3,7 mm/d y 9710 kg/ha, respectivamente. Conclusiones. El uso de un sistema de aeronave pilotada remotamente permitió mejorar la resolución temporal y espacial de las imágenes multiespectrales y térmicas para obtener mayor precisión en la evapotranspiración del cultivo (ETc) bajo dos regímenes de riego. En el riego con secas controladas se obtuvo una reducción del 24 % de la ETc lo que permitió un ahorro de agua de 855 m3/ha.

Summary: The middle area of the state of Sinaloa in Northwestern Mexico is characterized by a warm semi-arid climate where rainfall is insufficient for the adequate development of some introduced plant species. For example, those that correspond to the genus Brachiaria, despite technological advances in sencor development, the producers have limted access to sufficient meteorological information. Therefore, the aim in the present study is to determine water requirement, crop coefficient, and productivity of Convert 300 hybrid grass (Brachiaria sp) in a warm semiarid climate of Mexico by using the Food and Agriculture Organization (FAO56 Penman-Montiel equation) method with complete and limited data; a meteorological station was used to measure climatic parameters, and the FAO56 method with dual kc was applied to estimate crop evapotranspiration under non-standard conditions, and subsequently, water productiviy. The estimated water consumption for the Convert 330 hybrid in the warm semiarid climate of northwest Mexico was 1849 mm with measured data and 1973.5 mm with limited data. The statistical analyses yielded a coefficient of determination (R2) of 0.92, Willmott’s coefficient of agreement (d) of 0.90, RMSE of 0.694 mm d-1, BIAS of 0.380 mm d-1 and a Nash-Sutcliffe coefficient of efficiency (EF) of 0.98. The kc values were 0.49, 1.11 and 1.04 for initial, middle and end of season, respectively; the water productivity (WUE) was 2.666 kg m-3 for green forage, and 0.726 kg m-3, for dry matter, in the same way, 375.1 and 1378 L kg-1 were required to produce green forage and dry matter, respectively. To conclude, althought the ETc estimation with limited data overestimated the ETc with measured data by 6.7%, statistics showed that the procedure is reliable.

Resumen: La región central del estado de Sinaloa en el noroeste mexicano, se caracteriza por un clima semiárido cálido donde la precipitación es insuficiente para el desarrollo adecuado de algunas especies vegetales introducidas, como las correspondientes al género Brachiaria, a pesar del avance tecnológico en el desarrollo de sensores, es escaso el acceso de los productores a suficiente información meteorológica; el objetivo del presente trabajo consistió en determinar el requerimiento hídrico, coeficiente de cultivo y productividad del pasto híbrido Convert 330 (Brachiaria sp) en un clima semiárido cálido de México, utilizando el método FAO56 con datos medidos y datos limitados; se utilizó una estación meteorológica para medir los parámetros climáticos, y se aplicó el método FAO56 con kc dual para estimar la evapotranspiración de cultivo bajo condiciones no estándar, y posteriormente, la productividad del agua. El consumo de agua estimado para el pasto Convert 330 en clima semiárido cálido del noroeste de México fue de 1849 mm con datos medidos y 1973.5 mm con datos limitados; el análisis estadístico arrojó un coeficiente de determinación (R2) de 0.92, coeficiente de concordancia de Willmott (d) de 0.90, RMSE de 0.694 mm d-1, BIAS=0.380 mm d-1 y un coeficiente de eficiencia de Nash-Sutcliffe (EF) de 0.98. Los valores de kc obtenidos fueron de 0.49, 1.11 y 1.04 paras las etapas inicial, media y final, respectivamente; la productividad del agua (EUA) fue de 2.666 kg m-3 para forraje verde y 0.726 kg m-3 para materia seca; asimismo, se requirieron 375.1 y 1378 L kg-1 para la producción de forraje verde y materia seca, respectivamente. Finalmente, se concluye que, aunque la estimación de la ETc con datos limitados sobrestimó en un 6.7% la ETc con datos medidos, la estadística muestra que es confiable el procedimiento.

Abstract Introduction. The amount of usable water is currently limited due to the deterioration of its sources and indiscriminate use. An alternative to this problem is producing under green houses, where it is possible to obtain better water use efficiency (WUE) by reducing crop evapotranspiration (ETc) without compromising its productive potential. Objective. To evaluate the effect of 3 levels of volumetric moisture content depletion in coir on the vegetative-generative behavior of hydroponic tomato and sweet pepper produced under greenhouse cultivation. Materials and methods. The study was conducted during August to December 2020 and January 2021, at Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. Three treatments were applied: 11, 22 and 32% of water depletion in the substrate. Morphophysiological and reproductive parameters such as: the leaf area (AF), the number of leaves (NH), width (AH) and length of the leaf (LH), the length (LT) and the diameter of the stem (DT), the number of nodes (NN), dry matter (DM), stomatal conductance (gs), crop evapotranspiration (ETc), water use efficiency (WUE), the total yield (Rt), the commercial (Rc) of first (F1), second (F2) and third (F3) and waste fruits (Fd) were evaluated. Results. In the tomato treatments (TT) there was no effect on NH, LT, LH and NN; on the other hand, differences were reported in AH, DT and in MS, with treatment TT11 obtaining the higher values. The sweet pepper (TC), the treatment TC11 was statistically superior to the other treatments in number (NH), width (AH) and length (LH) of the leaf, in number of nodes (NN), production of fresh (MF) and dry matter (MS) and in diameter of the stem (DT), while there were no differences between treatments in stem length (LT). There were no differences in ETc and Rt, for both crops, but there was a difference in the commercial yield once it was divided by quality of fruit, TT11 presented the highest production of first and second fruit quality, while treatment TC11 presented the highest production of first, second and third fruit quality. For both crops, there were significant differences between treatments in terms of stomatal conductance. TT11 and TC11 treatments obtained the highest value of EUA with 37.32 kg.m-3 and 21.46 kg.m-3, respectively. Conclusion. In both crops, treatments with 11 and 22% water depletion showed an adequate balance between vegetative and productive growth, which was reflected in greater production of better quality commercial fruits, less waste and greater WUE.

Resumen Introducción. El uso de agua dulce en agricultura se encuentra limitado debido al deterioro de sus fuentes y su uso indiscriminado. El riego deficitario en agricultura protegida es una alternativa para mejorar la eficiencia en el uso del agua, a través de la reducción de la evapotranspiración del cultivo, sin comprometer su potencial productivo. Objetivo. Evaluar el efecto de 3 niveles de agotamiento del contenido de humedad volumétrica en un sustrato de fibra de coco, sobre el comportamiento vegetativo-generativo de los cultivos de tomate y chile dulce hidropónicos en invernadero. Materiales y métodos. El estudio se realizó en la Estación Experimental Agrícola Fabio Baudrit Moreno, Alajuela, Costa Rica. En ambos cultivos se aplicaron 3 tratamientos con 11, 22 y 32% de agotamiento hídrico en el sustrato, en un diseño experimental en bloques completos al azar. Se evaluaron parámetros morfofisiológicos y productivos tales como área foliar (AF), número de hojas (NH), ancho (AH) y longitud de hoja (LH), longitud (LT) y diámetro del tallo (DT), número de nudos (NN), materia seca (MS), conductancia estomática (gs), evapotranspiración del cultivo (ETc), eficiencia de uso de agua (EUA), rendimiento de fruto comercial (Rc) de primera (F1), segunda (F2) y tercera (F3), fruto de desecho (Fd) y rendimiento total (Rt). Resultados. En los tratamientos en tomate (TT) no hubo efecto sobre el NH, LH, LT y NN; mientras que con TT11 se obtuvieron valores superiores en AH, DT y MS. En chile dulce (TC), el TC11 obtuvo mayor NH, AH, LH, NN, DT y MS que los demás tratamientos; mientras que no hubo diferencias entre tratamientos en LT. En ambos cultivos, no hubo efecto sobre la ETc y el Rt, sin embargo, con 11% de agotamiento se obtuvo mayor producción comercial de F1 y F2 por lo que consecuentemente hubo mayor EUA con 37,32 kg.m-3 y 21,46 kg.m-3, respectivamente. Para ambos cultivos, la gs fue diferente entre tratamientos. Conclusión. En ambos cultivos, los tratamientos con 11 y 22% de agotamiento hídrico evidenciaron un adecuado balance entre crecimiento vegetativo y productivo, que se reflejó en mayor producción de frutos comerciales de mejor calidad, menos desecho y mayor EUA.

A comprehensive field investigation was conducted to enhance the productivity, profitability, and water use efficiency (WUE) of summer okra through the optimization of irrigation and nitrogen fertilizer application. The study involved 3 irrigation levels -0.75 Epan (pan evaporation) as I1, 1.00 Epan as I2, and 1.25 Epan as I3- as the main plot factors, and 4 nitrogen concentrations - 75% recommended nitrogen dose (RDN) as N1, 100% RDN as N2, 125% RDN as N3, and 150% RDN as N4- as the subplot variables. The results of the study revealed a significant influence of irrigation and nitrogen levels on various key parameters. Above-ground dry matter, yield, plant height, WUE, net returns, and benefit-to-cost ratio (B:C) exhibited an incremental trend with increasing irrigation and nitrogen levels, up to a certain threshold. Beyond this threshold, further increments in irrigation and nitrogen led to diminishing returns. The models developed for estimating crop yield, above-ground drv matter, plant height, WUE, net returns, and B:C demonstrated impressive accuracy, with high coefficients of determination (R²) and satisfactory precision. The optimized irrigation level (crop evapotranspiration, ET C) ranged from 418.39-441.23 mm. At the same time, the ideal nitrogen application rate was found to be in the range of 167.04-176.13 kg N/ha. These optimal conditions resulted in peak crop yield of 28 295 kg/ha, above-ground dry matter of 6 709.1 kg/ha, plant height of 66.3 cm, WUE of 5.26 kg/m³, B:C of 4.54, and net returns amounting to 441 133 INR/ha. In conclusion, the application of response surface methodology facilitated the identification of the impact of each factor on individual responses, as well as the determination of optimal conditions that simultaneously maximize multiple desirable outcomes. These findings hold significant promise for improving the cultivation of summer okra while optimizing resource use and economic returns.

ABSTRACT The collapse of the Fundão Dam in Mariana, MG, in 2015 introduced the challenge of using Technosol, a soil type formed by deposition of iron mining waste along the Doce River banks, for agricultural purposes. This study aimed to determine the optimal water depth for enhancing production of tropical forage, Megathyrsus maximus cv. Mombasa, when grown on iron ore tailings. Additionally, it sought to establish a crop coefficient applicable to the edaphoclimatic conditions of Viçosa, MG, Brazil. The experiment was conducted throughout the summer, fall, and winter of 2022, employing 21 drainage lysimeters. A completely randomized experimental design was adopted, featuring six treatment groups (plants in Technosol receiving water depths ranging from 20 to 120% of the crop’s evapotranspiration, as derived from the control treatment), along with a control group (plants in Latosol with a depth of 100%), each with three repetitions. Our findings showed that irrigation must replace 40% of the crop evapotranspiration. Moreover, cultivating in Technosol resulted in a reduction of productive capacity by 37.39% during the summer/fall and fall seasons. For Mombasa grass grown in Oxisol, crop coefficients of 1.2 during the summer and 1.5 during the fall and winter are advised. Mariana MG 201 banks purposes forage cv tailings Additionally Viçosa Brazil 2022 2 lysimeters adopted plants 120 crops s evapotranspiration treatment, , treatment) 100%, 100 100% 100%) repetitions 40 Moreover 3739 37 39 37.39 summerfall seasons Oxisol 12 1 1. 15 5 advised 202 10 4 373 3 37.3 37.

RESUMO O rompimento da Barragem do Fundão em Mariana, MG, ocorrida em 2015, trouxe o desafio de usar o Tecnossolo (tipo de solo) formado pela deposição do rejeito de mineração de ferro nas margens do Rio Doce para agricultura. O objetivo desta pesquisa foi obter a lâmina de água para otimizar a produção da forragem tropical Megathyrsus maximum cv. Mombaça, cultivada em rejeito de mineração de ferro e determinar seu coeficiente de cultura para as condições edafoclimáticas de Viçosa, MG. O experimento foi realizado durante as estações de verão, outono e inverno do ano de 2022, com a utilização de 21 lisímetros de drenagem. O experimento foi distribuído em delineamento inteiramente casualizado com 6 tratamentos (plantas em Tecnossolo com lâminas variando de 20 a 120% da evapotranspiração da cultura, obtida do tratamento-testemunha) e adição de uma testemunha (plantas em Latossolo com lâmina de 100%) com três repetições. Recomenda-se irrigação com reposição de 40% da evapotranspiração da cultura. O cultivo em Tecnossolo diminuiu a capacidade produtiva em 37,39% nos ciclos das estações do verão/outono e outono. Recomenda-se os coeficientes de cultura de 1,2 no verão e 1,5 no outono e no inverno, para o capim-Mombaça cultivado em um Latossolo. Mariana MG 2015 tipo solo agricultura cv Mombaça Viçosa 2022 2 drenagem plantas 120 tratamentotestemunha tratamento tratamento-testemunha 100% 100 repetições Recomendase Recomenda se 40 3739 37 39 37,39 verãooutono 12 1 1, 15 5 capimMombaça capim 201 202 10 4 373 3 37,3 37,

ABSTRACT Cowpea is a crop of high socioeconomic importance for the semi-arid region of Brazil, although facing significant yield losses due to drought, requiring management strategies to overcome this scenario. From this perspective, this study aimed to evaluate the growth and yield of cowpea genotypes under drought in different cultivation systems. The statistical design was randomized blocks arranged in a 2 × 4 × 2 factorial scheme corresponding to two cowpea genotypes (BRS Pujante and Costela de Vaca), four levels of crop evapotranspiration (40, 60, 80, and 100%), and two cultivation systems (with and without soil mulching). The BRS Pujante showed a higher leaf area and 100-grain weight than Costela de Vaca under all levels of crop evapotranspiration. The cowpea yield parameters showed the best results at 80 and 100% crop evapotranspiration. Regardless of the genotype, soil mulching provided higher cowpea 100-grain weight values. Soil mulching combined with 80% crop evapotranspiration is an appropriate strategy for cowpea production. semiarid semi arid Brazil scenario perspective Vaca, , Vaca) 40, 40 (40 60 100%, 100 100%) mulching. . mulching) 100grain grain 8 genotype values production (4 6 10 ( 1

RESUMO O feijão-caupi tem grande importância socioeconômica para o semiárido brasileiro, porém sofre perdas significativas de produção pelo estresse por seca, necessitando de estratégias de manejo para superar esse cenário. Nessa perspectiva, o presente estudo teve como objetivo avaliar o crescimento e a produção de genótipos de feijão-caupi sob estresse hídrico em diferentes sistemas de cultivo. O delineamento estatístico adotado foi o de blocos casualizados, em arranjo fatorial 2 × 4 × 2, correspondendo a dois genótipos de feijão-caupi (BRS Pujante e Costela de Vaca), quatro níveis de evapotranspiração da cultura (40, 60, 80 e 100%) e dois sistemas de cultivo (com e sem cobertura morta do solo). O genótipo de feijão-caupi BRS Pujante apresentou maior área foliar e peso de 100 grãos do que o genótipo Costela de Vaca em todos os níveis de evapotranspiração da cultura. Os parâmetros de produção do feijão-caupi apresentaram os melhores resultados a 80 e 100% da evapotranspiração da cultura. Independentemente do genótipo, a cobertura morta do solo proporcionou maiores valores de peso de 100 grãos de feijão-caupi. A cobertura do solo combinada com 80% da evapotranspiração da cultura é uma estratégia adequada para a produção de feijão-caupi. feijãocaupi feijão caupi brasileiro seca cenário perspectiva casualizados Vaca, , Vaca) 40, 40 (40 60 8 solo. . solo) 10 feijãocaupi. caupi. (4 6 1 (

ABSTRACT During the agronomic design of micro-sprinkling systems, it is difficult to guarantee the wetting of a volume of roots that allows the appropriate extraction of water and nutrients, as well as adequate anchorage. This leads to extreme precision at this stage, essentially in the estimation of crop coefficients KC, irrigation location coefficient KL and climatic variability coefficient KVC, as well as leaching requirements LR. When these are not estimated in a rigorous manner, the results can affect irrigation efficiency and the profitability of the installation. Identifying the effects of simplifications made during agronomic design on the accuracy of the capability's operating parameters is one of the ways to contribute to agricultural food production, considering the rational and efficient use of water. The research used the design procedure proposed by Keller and Rodrigo/1979, and the hypothetical-deductive method was also used to evaluate the effects of simplifications in the operating parameters of the installation. As a result, arguments were obtained that allow establishing the effects of simplifications in the rigor of the results of the agronomic design of localized irrigation systems, which allow us to conclude that the rigorous agronomic design of localized irrigation systems with micro-sprinkling leads to establishing effective installations.

RESUMEN Durante el diseño agronómico de sistemas de riego por microaspersión es difícil garantizar humedecer un volumen de raíces que permita la apropiada extracción de agua y nutrientes, así como el anclaje adecuado. Esto conlleva a extremar la precisión en esta etapa, esencialmente, en la estimación de los coeficientes de cultivo KC , de localización del riego KL y de variabilidad Climática KVC , así como de las necesidades de lavado LR. Cuando la estimación de éstos no se realiza de manera rigurosa, los resultados pueden afectar la eficacia del riego y la rentabilidad de la instalación. Identificar los efectos de las simplificaciones realizadas durante el diseño agronómico, en la precisión de los parámetros de explotación de la instalación, constituye una de las maneras de contribuir a la producción de alimentos agrícolas, considerando el uso racional y eficiente del agua. En la investigación se utilizó el procedimiento de diseño propuesto por Keller y Rodrigo/1979, se empleó además el método hipotético - deductivo, para evaluar los efectos de las simplificaciones en los parámetros de explotación de la instalación. Como resultado, se obtuvieron argumentos que permiten establecer los efectos de las simplificaciones en el rigor de los resultados del diseño agronómico de sistemas de riego localizado, los cuales permiten concluir que el diseño agronómico riguroso de sistemas de riego localizado con Microaspersores conlleva a establecer instalaciones eficaces.

ABSTRACT Population growth has led to an exponential demand for agricultural products, to meet this demand it is necessary to improve management and achieve efficient use of resources without compromising the sustainability of ecosystems, particularly agricultural ones. One of the technologies that facilitate these tasks is precision agriculture (PA), which focuses on the optimization of resources and inputs based on the compilation of precise and timely geo-information of variables of agricultural interest with high spatio-temporal variability, obtained through remote sensors of three types: images captured by satellites or airplanes, images obtained from manned and unmanned aerial vehicles (UAVs) and specific information with sensors mounted on machinery or in the field. These limitations were overcome by using multispectral images, which has increased applications for agricultural purposes. Currently, multispectral images allow quantifying soil moisture, monitoring the presence of droughts and the degree of crop water stress, estimating the temporal and spatial variability of evapotranspiration, monitoring phenology, detecting nutritional deficiencies, estimating the degree of weed infestation. and insects, calculate organic carbon and soil salinity, and estimate yields and agricultural production. The use of geospatial technologies in the PA has changed the paradigm of agriculture and today constitutes a viable alternative to face the challenges that food production demands in a world with high climate variability.

RESUMEN El crecimiento poblacional ha derivado en una demanda exponencial de productos agrícolas, para cubrir esta demanda se requiere mejorar la gestión y lograr un uso eficiente de recursos sin comprometer la sustentabilidad de los ecosistemas, en particular los agrícolas. Una de las tecnologías que facilitan estas tareas es la agricultura de precisión (AP), que se enfoca en la optimización de recursos e insumos basado en la compilación de geo información precisa y oportuna de variables de interés agrícola de alta variabilidad espacio-temporal, obtenida mediante sensores remotos de tres tipos: imágenes capturadas por satélites o aviones, imágenes obtenidas desde vehículos aéreos tripulados y no tripulados (VANT’s) e información puntual con sensores montados en maquinaria o en campo. Estas limitantes se superaron al usar imágenes multiespectrales, lo que ha incrementado las aplicaciones con fines agrícolas. Actualmente, las mágenes multiespectrales permiten cuantificar la humedad del suelo, monitorear la presencia de sequías y el grado de estrés hídrico de cultivos, estimar la variabilidad temporal y espacial de la evapotranspiración, dar seguimiento fenológico, detectar deficiencias nutricionales, estimar grado de infestación de malezas e insectos, calcular carbono orgánico y salinidad del suelo y estimar rendimientos y producción agrícola. El uso de tecnologías geoespaciales en la AP ha cambiado el paradigma de la agricultura y hoy en día constituye una alternativa viable para afrontar los retos que demanda la producción de alimentos en un mundo con alta variabilidad climática.

Abstract In view of the growing scarcity of water for agriculture, the increase in food demand and future drought scenarios posed by climate change, it is essential to design new technologies that contribute to lower water consumption. In this research, high-resolution images have been used to estimate evapotranspiration in rice fields by applying the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) energy balance model. For this purpose, 5900 m2 of crop were monitored under continuous flood irrigation (CF) and 2600 m2 under alternate wetting and drying irrigation (AWD), in addition to some plots with lateral filtration. Ten flights were conducted between tillering and flowering phases, five flights with a Matrice 210 UAV equipped with a Parrot Sequoia multispectral camera, and five flights with a Matrice 300 RTK equipped with a H20T thermal camera. Field data were collected from vegetation indices (NDVI and LAI), and readings from a radiometer, to adjust information from multispectral and thermal images, respectively, and to obtain the components of the surface energy balance. Mean values for crop evapotranspiration (ETc) of 6.34 ± 1.49 and 5.84 ± 0.41 mm d-1 were obtained for IC irrigation and AWD irrigation, respectively, obtaining a water saving of 42% with a yield reduction of 14%, providing a guide for proper irrigation management, however, it is suggested to use the model to optimize yield by obtaining critical thresholds for optimal application of AWD in the face of water resource scarcity.

Resumen Ante la creciente escasez del agua para la agricultura, el incremento de la demanda de alimentos y los futuros escenarios de sequía que nos plantea el cambio climático es indispensable diseñar nuevas tecnologías que contribuyan a un menor consumo de agua. En esta investigación se han empleado imágenes de alta resolución para estimar la evapotranspiración en arrozales aplicando el modelo de balance de energía METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration). Para ello, se monitorizaron 5900 m2 de cultivo bajo riego por inundación continua (IC) y 2600 m2 bajo la técnica de riego de alternancia humedecimiento y secado (AWD, por sus siglas en inglés), además de algunas parcelas con filtración lateral. Se realizaron 10 vuelos entre las etapas de macollamiento y floración, cinco vuelos con un VANT Matrice 210 con una cámara multiespectral Parrot Sequoia, y cinco vuelos con un Matrice 300 RTK equipado con una cámara térmica H20T. Se colectó información de campo de los índices de vegetación (NDVI e IAF), y lecturas de un radiómetro, para ajustar información de las imágenes multiespectrales y térmicas, respectivamente; y obtener los componentes del balance de energía en superficie. Se obtuvo valores medios para evapotranspiración del cultivo (ETc) de 6,34 ±1,49 y 5,84 ± 0,41 mm d-1 para riego IC y riego AWD, respectivamente, obteniéndose un ahorro de agua del 42% con una reducción del rendimiento en 14%, proporcionando una guía para la gestión adecuada del riego, sin embargo, se sugiere utilizar el modelo para optimizar el rendimiento obteniendo umbrales críticos para la aplicación óptima de AWD frente a la escasez del recurso hídrico.

Abstract This study aimed to determine the drought stress response of Fawn-tall fescue and Tekapo-orchard grass and investigate a drought stress resistance marker. Grass genotypes were grown under four Irrigation treatments I1 equivalent to 0.3 standard crop evapotranspiration (ETc), I2 equivalent to 0.65 ETc, I3 equivalent to 0.75 ETc, and I4 equivalent to 1.2 ETc. Plant height, fresh weight, dry weight were measured and the Water productivity (WP) were calculated. The results showed a reduction in the growth of both grass genotypes as the drought stress increased as indicated by the shorter plants and reduction in fresh and dry weight. However, the WP results showed that the Fawn-tall fescue endured the drought stress better than the Tekapo-orchard grass as indicated by the constant values of the plant WP across the tested irrigation treatments. The results was confirmed by the amplification of dehydrin genes where Fawn-tall fescue was found to be homozygous for dehydrin genes. Fawntall Fawn tall Tekapoorchard Tekapo orchard marker I 03 0 3 0. ETc , (ETc) 065 65 0.6 075 75 0.7 12 1 2 1. height (WP calculated However (ETc 06 6 07 7

Resumo Este estudo teve como objetivo determinar a resposta ao estresse hídrico da Festuca Fawn-tall e do Capim-pomar Tekapo e investigar um marcador de resistência ao estresse hídrico. Genótipos de gramíneas foram cultivados sob quatro tratamentos de irrigação em que I1 é equivalente a 0,3 da evapotranspiração padrão da cultura (ETc), I2 equivalente a 0,65 ETc, I3 equivalente a 0,75 ETc, e I4 equivalente a 1,2 ETc. Altura da planta, peso fresco, peso seco foram medidos e a produtividade de água (WP) foi calculada. Os resultados mostraram uma redução no crescimento de ambos os genótipos de gramíneas à medida que o estresse hídrico aumentou, conforme indicado pelas plantas mais baixas e redução no peso fresco e seco. No entanto, os resultados do WP mostraram que a espécie Festuca Fulvo-Tall suportou o estresse hídrico melhor do que a grama Capim-pomar Tekapo, conforme indicado pelos valores constantes do WP da planta em todos os tratamentos de irrigação testados. Os resultados foram confirmados pela amplificação dos genes da deidrina, em que a Festuca Fulvo-Tall foi encontrada e classificada como homozigótica para tais genes. Fawntall Fawn tall Capimpomar Capim pomar I 03 0 3 0, ETc , (ETc) 065 65 0,6 075 75 0,7 12 1 2 1, (WP calculada aumentou entanto FulvoTall Fulvo Tall testados deidrina (ETc 06 6 07 7

Abstract Onion is considered a major vegetable crops all over the world. In arid zones water deficit can affect the yield of crops such as onion. Through this research, four levels of irrigation were used (100% of the calculated crop evapotranspiration ET100, 80% of the calculated crop evapotranspiration ET80, 70% of the calculated crop evapotranspiration ET70, and 60% of the calculated crop evapotranspiration ET60) in combination with two levels of fertilization (100% of the recommended fertilization NPK100 and 75% of the recommended fertilization NPK75). The total yield (fresh weight) of each experimental unit were harvested, weighed, and then sorted into marketable and unmarketable and both the overall and the marketable water use efficiency were calculated. The results were statically analyzed using the ANOVA analysis and the means were compared using the Duncan LSD method. Principle Component Analysis (PCA) was used to classify the treatments into clusters. Results used indicated that the water use efficiency of onion increase if a mild drought stress (85% of the calculated crop evapotranspiration) were exerted on the plants at 100% of the recommended fertilization level. The availability of fertilizers helps the plant manage the drought stress while keeping an adequate level of yield. The lack of fertilizers combined with the drought stress resulted in rapid decrease in the yield thus decreasing the water use efficiency. The recommended water deficit level under these circumstances would be 88.9% of the plant water requirements. world research 100 (100 ET100 ET 80 ET80 70 ET70 60 ET60 NPK NPK10 75 NPK75. NPK75 . NPK75) fresh weight harvested weighed method PCA (PCA clusters 85% 85 (85 889 88 9 88.9 requirements 10 (10 ET10 8 ET8 7 ET7 6 ET6 NPK1 NPK7 (8 88. 1 (1 ET1 (

Resumo A cebola é considerada uma das principais hortaliças em todo o mundo. Nas zonas áridas, o déficit hídrico pode afetar o rendimento de culturas como a cebola. Nesta pesquisa foram utilizados quatro níveis de irrigação (100% da evapotranspiração calculada da cultura ET100, 80% da evapotranspiração calculada da cultura ET80, 70% da evapotranspiração calculada da cultura ET70 e 60% da evapotranspiração calculada da cultura ET60) em combinação com dois níveis de adubação (100% da adubação recomendada NPK100 e 75% da adubação recomendada NPK75). A produção total (peso fresco) de cada unidade experimental foi colhida, pesada e, em seguida, classificada em comercializável e não comercializável e calculada a eficiência geral e a comercializável do uso da água. Os resultados foram analisados estatisticamente pela análise ANOVA, e as médias foram comparadas pelo método Duncan LSD. A Análise de Componentes Principais (PCA) foi utilizada para classificar os tratamentos em clusters. Os resultados utilizados indicaram que a eficiência do uso da água pela cebola aumenta se um leve estresse hídrico (85% da evapotranspiração calculada da cultura) for exercido sobre as plantas a 100% do nível de fertilização recomendado. A disponibilidade de fertilizantes ajuda a planta a gerir o estresse hídrico, mantendo um nível adequado de rendimento. A falta de fertilizantes, combinada com o estresse hídrico, resultou numa rápida diminuição do rendimento, diminuindo assim a eficiência do uso da água. O nível de déficit hídrico recomendado nestas circunstâncias seria de 88,9% das necessidades hídricas da planta. mundo áridas 100 (100 ET100 ET 80 ET80 70 ET7 60 ET60 NPK NPK10 75 NPK75. NPK75 . NPK75) peso fresco colhida seguida ANOVA LSD PCA (PCA clusters 85% 85 (85 889 88 9 88,9 10 (10 ET10 8 ET8 7 6 ET6 NPK1 NPK7 (8 88, 1 (1 ET1 (

Abstract Excessive salts in irrigation water and water stress have a negative impact on the productive yield of agricultural crops. In this regard, the objective was to evaluate the effect of combined saline and water stress on the agronomic performance of the beet crop. The experiment was conducted in a greenhouse located at the Universidade da Integração Internacional da Lusofonia Afro-Brasileira, in Redenção, Ceará. The experimental design used was completely randomized with split-plots arrangement. The main plots were formed by the electrical conductivities of the irrigation water (0.8, 1.5, 3.0, 4.5, and 6.0 dS m-1), while the irrigation depths of 50 and 100% of the crop evapotranspiration (ETc) were the subplots, with 6 replications. Saline stress negatively affected growth, biomass, tuber root length, and productivity, while increasing the soluble solids of the beet crop. Excessive salts in the irrigation water caused reductions in physiological indices of the beet crop, although with less severity under the 100% ETc. crops regard AfroBrasileira, AfroBrasileira Afro Brasileira, Brasileira Afro-Brasileira Redenção Ceará splitplots split arrangement 0.8, 08 0 8 (0.8 15 1 5 1.5 30 3 3.0 45 4 4.5 60 6. m1, m1 m , m-1) 100 ETc (ETc subplots replications growth biomass length productivity 0.8 (0. 1. 3. 4. m-1 10 0. (0 m- (

Resumo O excesso de sais na água de irrigação e o estresse hídrico, afetam negativamente o rendimento produtivo das culturas agrícolas. Neste sentido, objetivou-se avaliar o efeito do estresse salino associado ao hídrico no desempenho agronômico da cultura da beterraba. O experimento foi conduzido em casa de vegetação, em área pertencente a Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Redenção, Ceará. O delineamento experimental utilizado foi inteiramente casualizado, em parcelas subdivididas. As parcelas foram formadas pelas condutividades elétricas da água de irrigação (0,8; 1,5; 3,0; 4,5 e 6,0 dS m-1), enquanto os regimes hídricos de 50 e 100% da evapotranspiração da cultura (Etc), foram as subparcelas, com 6 repetições. O estresse salino afetou negativamente o crescimento, a biomassa, o comprimento da raiz tuberosa e a produtividade e aumentou os sólidos solúveis da cultura da beterraba. O excesso de sais da água de irrigação provoca reduções nos índices fisiológicas da cultura da beterraba, porém com menor severidade no regime hídrico de 100% da ETc. agrícolas sentido objetivouse objetivou se beterraba vegetação AfroBrasileira, AfroBrasileira Afro Brasileira, Brasileira Afro-Brasileira Redenção Ceará casualizado subdivididas 0,8 08 0 8 (0,8 1,5 15 1 5 3,0 30 3 45 4 4, 60 6, m1, m1 m , m-1) 100 Etc, Etc (Etc) subparcelas repetições crescimento biomassa ETc 0, (0, 1, 3, m-1 10 (Etc (0 m- (