RESUMO O pimentão, cultura de importância nutricional, destaca-se por seu valor de vitamina C. Diante da necessidade de práticas agrícolas sustentáveis, o estudo explorou o uso de biocarvões derivados de resíduos regionais como alternativa na cultura de pimentão. Nesse contexto, objetivou-se avaliar o efeito de biocarvões provenientes de cama de frango, fibra de coco e palha de arroz, nas características biométricas e físico-químicas de frutos de pimentão verde, na produção de frutos por planta e na produtividade. A pesquisa foi conduzida em campo no delineamento em blocos casualizados, em esquema fatorial 5 × 3 + 1, referentes a cinco doses de biocarvão (0, 3, 6, 9 e 12 t ha-1) e três tipos de biocarvão (fibra de coco, cama de aviário e palha de arroz) com quatro repetições, mais um tratamento adicional (adubação mineral). Foram avaliadas variáveis biométricas (comprimento e diâmetro dos frutos, espessura da casca, número de frutos, massa do fruto) e físico-químicas dos frutos (sólidos solúveis, acidez titulável, pH, vitamina C e teor de cinzas), produção e produtividade dos frutos. A produção de frutos de pimentão verde não foi influenciada pelos biocarvões, porém as doses de biocarvões influenciaram todas as variáveis analisadas com exceção da espessura da casca. Os teores de vitamina C e de sólidos solúveis foram maiores nos tratamentos com biocarvões e menores com adubação mineral. A maior influência na acidificação dos frutos foi com o biocarvão produzido com palha de arroz. nutricional destacase destaca se sustentáveis contexto objetivouse objetivou frango arroz físicoquímicas físico químicas casualizados 1 0, 0 (0 6 ha1 ha ha-1 repetições mineral . mineral) comprimento casca fruto titulável pH cinzas, cinzas , cinzas) ( ha-

ABSTRACT Bell pepper, a crop of nutritional importance, stands out for its vitamin C content. Given the need for sustainable agricultural practices, the present study explored the use of biochars derived from regional waste as an alternative in bell pepper cultivation. In this context, the present study aimed to evaluate the effect of biochars from poultry litter, coconut fiber, and rice straw on the biometric and physicochemical characteristics of bell pepper fruits, on fruit production per plant and on fruit yield. The experiment was performed in the field in a randomized block design, in a 5 × 3 + 1 factorial scheme, referring to five doses of biochar (0, 3, 6, 9, and 12 t ha-1) and three types of biochar (coconut fiber, poultry litter, and rice straw) with four repetitions, plus an additional treatment (mineral fertilization). Biometric variables (fruit length and diameter, skin thickness, number of fruits, fruit mass) and physicochemical variables of the fruits (soluble solids, titratable acidity, pH, vitamin C, and ash content), production and yield of the fruits were evaluated. The production of bell pepper fruits was not influenced by biochars, but the doses of biochars influenced all variables analyzed with the exception of skin thickness. Vitamin C and soluble solids contents were higher in treatments with biochar and lower with mineral fertilizer. Biochar produced from rice straw had the greatest influence on fruit acidification. importance content practices cultivation context litter fiber design scheme 0, 0 (0 6 9 ha1 ha ha-1 repetitions fertilization. fertilization . fertilization) diameter thickness mass acidity pH content, , content) evaluated fertilizer acidification ( ha-

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.

ABSTRACT Fossil fuels, particularly oil, face sustainability challenges due to depletion and their role in increasing atmospheric CO2 levels, contributing to climate change and impacting global agriculture. Renewable energy sources like solar power offer a viable alternative. This study explores the feasibility of agro-photovoltaic (APV) systems, which integrate solar panels with agricultural land to generate electricity while cultivating crops. Specifically, the impact of APV systems on rice production and quality was investigated. Solar modules with a total capacity of 99.84 kW were installed on a 2580 m2 site, with two module configurations tested. Two rice (Oryza sativa L.) cultivars, Woonkwang and Saenuri, were transplanted and monitored for growth characteristics, chlorophyll content, and fluorescence, as well as yield and quality. Growth analysis of rice under APV systems showed minimal impact on plant height and tiller numbers, though chlorophyll content analysis indicated delayed leaf aging and extended maturation time. Rice yield decreased due to altered panicle and spikelet numbers. Quality analysis revealed changes in head rice rate and broken rice, stressing optimal harvest timing in APV systems. Shading conditions also affected physicochemical properties and taste profiles. Yields dropped by about 20% under APV systems, but the financial returns from electricity generation significantly outweighed the crop revenue loss. Despite the high initial installation costs and regulatory challenges, APV systems present a promising dual-use approach for enhancing farm income and promoting renewable energy. Continued research and investment are essential for optimizing APV systems and expanding their adoption.

ABSTRACT Lowland rice in Santa Catarina (SC), Brazil, is grown as a sole crop, which has aggravated problems with weeds. In this context, the objective of this study was to evaluate the efficacy of weed management systems in soybean crops to decrease weed infestation in lowland rice production areas, using pre- and post-emergence herbicides. The experiment was conducted in Turvo, SC, from August 2021 to April 2022. A randomized block design with four replications was used, in a 6 × 5 factorial arrangement. The factors consisted of six pre-emergence herbicides treatments (S-metolachlor, diclosulam, sulfentrazone, sulfentrazone + diuron, pyroxasulfone + flumioxazin, and a control without herbicide), and five post-emergence herbicide treatments: control without herbicide, glyphosate at two rates (930 and 1,550 g a.e. ha-1), applied alone or in combination with clethodim. The herbicide sulfentrazone caused persistent phytotoxicity and resulted in the lowest soybean grain yield. The herbicide S-metolachlor was ineffective in controlling weed species, except barnyard grass, even when combined with post-emergence application. The poor control of these weed species does not result in significant interference, causing no significant decreases in grain yield of soybean crops grown in floodplain soils. The use of S-metolachlor, diclosulam, and pyroxasulfone + flumioxazin, combined with post-emergence application of glyphosate (930 g a.e. ha-1), resulted in highly effective control of barnyard grass, inhibiting weed seed production. Only the combination of glyphosate (1,550 g a.e. ha-1) with clethodim can suppress barnyard grass seed production without using pre-emergence herbicides. SC , (SC) Brazil crop weeds context areas pre postemergence post emergence Turvo 202 2022 used arrangement preemergence Smetolachlor, Smetolachlor S metolachlor, metolachlor (S-metolachlor diclosulam diuron flumioxazin herbicide) 930 (93 1550 1 550 1,55 ae e a.e ha1, ha1 ha interference soils (1,55 ha-1 (SC 20 93 (9 155 55 1,5 (1,5 ha- 2 9 ( 15 1, (1, (1

RESUMO O arroz irrigado em Santa Catarina é cultivado em monocultivo, o que tem agravado os problemas com plantas daninhas. Deste modo, o objetivo deste estudo foi avaliar a eficiência de sistemas de manejo de plantas daninhas na cultura da soja sobre a redução da infestação de plantas daninhas em uma área de produção de arroz irrigado, utilizando para isso herbicidas em pré e/ou pós-emergência da soja. O experimento foi conduzido no município de Turvo - SC no período de agosto de 2021 a abril de 2022. Utilizou-se o delineamento de blocos casualizados com tratamentos organizados em esquema fatorial 6 × 5, com quatro repetições. O fator A constou de seis tratamentos aplicados em pré-emergência, os herbicidas utilizados foram: S-metolachlor, diclosulam, sulfentrazone, sulfentrazone + diuron, pyroxasulfone + flumioxazin, além de uma testemunha sem herbicida. Já o fator B constou de cinco tratamentos aplicados em pós-emergência: testemunha sem herbicida, gyphosate em duas doses (930 e 1550 g e.a. ha-1), aplicadas de forma isoladas ou em associação com clethodim. O herbicida S-metolachlor foi ineficiente para o controle de outras plantas daninhas, mesmo quando combinado com a aplicação em pós-emergência. O controle deficiente destas espécies não resulta em significativa interferência, não causando decréscimo na produtividade de grãos da soja, em ambientes de terras baixas. O uso dos herbicidas S-metolachlor, diclosulam e pyroxasulfone + flumioxazin, combinados com a aplicação em pós-emergência de glyphosate (930 g e.a. ha-1) resultou em controle eficiente de capim-arroz e inibiu a produção de sementes. Apenas a associação de glyphosate (1550 g e.a. ha-1) com clethodim suprimiu a produção de sementes de capim-arroz, sem a aplicação de herbicidas em pré-emergência. monocultivo modo eou pósemergência pós emergência 202 2022 Utilizouse Utilizou se 5 repetições préemergência, préemergência emergência, pré-emergência foram Smetolachlor, Smetolachlor S metolachlor, metolachlor diuron flumioxazin 930 (93 155 ea e.a ha1, ha1 ha 1 , pósemergência. emergência. interferência baixas ha-1 capimarroz capim (155 capimarroz, arroz, préemergência. 20 93 (9 15 ha- (15 2 9 ( (1

Abstract Introduction. Saline soils are a threat to crop productivity, which occurs in the rice-growing areas of Ecuador. Objective. To assess the changes in the chemical properties of 3 experimental soils caused by the effect of the application of mineral amendments, particularly the effects on the variables related to salinity. Materials and methods. The calcium amendments tested (CaCO3, Ca(OH)2, CaSO4.2H2O, Ca2SiO4) and a zeolite, were applied in five doses to the rice crop. The experimental design was completely randomized, with a 3 x 5 x 5 x 3 factorial arrangement of the treatments. Each treatment was repeated three times. Results. The treatments caused changes in the electric conductivity (EC) and pH of the soil solution and in soil fertility. The salinity of the soils in the study area is due to the presence of Na+, K+, Ca2+ and mainly Mg2+. Conclusions. the use of amendments: CaSO4, zeolite and Ca(OH)2, improved the chemical properties of the soils by decreasing the EC of the soil solution.

Resumen Introducción. Los suelos salinos son una amenaza para la productividad de los cultivos, lo que ocurre en las zonas arroceras del Ecuador. Objetivo. Evaluar los cambios en algunas propiedades químicas en 3 suelos debido al efecto de la aplicación de 5 enmiendas minerales, particularmente los efectos sobre las variables relacionadas con la salinidad. Materiales y métodos. Las enmiendas cálcicas ensayadas (CaCO3, Ca(OH)2, CaSO4.2H2O, CaSiO4) y una zeolita, se aplicaron en 5 dosis al cultivo de arroz. El diseño experimental fue completamente al azar, con arreglo factorial 3 x 5 x 5 x 3 de los tratamientos. Cada tratamiento se repitió 3 veces. Resultados. Los tratamientos provocaron cambios en la Conductividad eléctrica (CE) y pH de la solución del suelo y en la fertilidad del suelo. La salinidad de los suelos en la zona de estudio se debe a la presencia de Na+, K+, Ca2+ y principalmente Mg2+ en el extracto de saturación de los suelos. Conclusiones. El uso de enmiendas en general, específicamente CaSO4, zeolita y Ca(OH)2, mejoraron las propiedades químicas de los suelos al reducir la CE de la solución del suelo.

Abstract Rice (Oryza sativa L.) is an important source of energy in the human diet; and, in Nicaragua, it constitutes a substantial component of the population's diet. The present study was exploratory, and aimed to determine the diversity of arthropods associated with rice cultivation in the municipality of Sébaco, an intensive rice production region, in the 2022-2023 agricultural cycle. Production systems with extensions over 100 hectares, where equal agronomic and phytosanitary management was used, were selected. For entomofauna monitoring, ten points were randomly selected in each production system, and at each point, and 20 double zigzag passes with entomological nets were used at each point. The number of individuals per order and family was quantified. For the diversity analysis, they were grouped according to their feeding habits. Abundance and richness information was analyzed using descriptive analysis, analysis of variance, and Shannon Weaver and Simpson's diversity index. Seven orders, 13 families, and 16 genera were found, most of them of the phytophagous habit. The highest abundance corresponded to the species T. orizicolus Muir (n = 46,663), reported in the reproductive and maturation phases. Likewise, Hydrellia sp (n = 5,229) presented the largest populations in the vegetative phase. Among the beneficial organisms, siders (n = 1,523) and Atrichopogum sp (n = 419) stood out. Diversity indices were low both in the production systems and in the different phenological phases of the crop.

Resumen El cultivo de arroz (Oryza sativa L.) representa una fuente de energía de importancia en la dieta humana, y en Nicaragua constituye un sustancial componente de la dieta de la población. El presente estudio fue exploratorio y tuvo como objetivo determinar la diversidad de artrópodos asociada al cultivo de arroz en el municipio de Sébaco, en el ciclo agrícola 2022-2023, una región intensiva en la producción de arroz. Se seleccionaron sistemas productivos con extensiones mayores a 100 hectáreas, en donde se empleó igual manejo agronómico y fitosanitario. Para el monitoreo de la entomofauna, en cada sistema productivo se seleccionaron diez puntos al azar y en cada punto se emplearon 20 pases dobles en forma de zig-zag con red entomológica. Se cuantifico el número de individuos por orden y familia; para el análisis de diversidad se agruparon por sus hábitos alimenticios. La información de la abundancia y riqueza se analizó mediante estudio descriptivo, análisis de varianza e índice de diversidad de Shannon Weaver y Simpson. Se encontraron siete órdenes, 13 familias y 16 géneros, la mayoría del hábito fitófago. La mayor abundancia correspondió a la especie T. orizicolus Muir (n=46.663), reportada en la fase reproductiva y maduración. Así mismo, Hydrellia sp (n=5.229), presentó las mayores poblaciones en la fase vegetativa. Dentro de los organismos benéficos sobresalieron las arañas (n=1.523) y Atrichopogum sp (n=419). Los índices de diversidad fueron bajos tanto en los sistemas productivos como en las diferentes fases fenológicas del cultivo.

Abstract Rice farming in Madiun Regency implements three different management systems, that is organic, semi-organic, and conventional. The different implementation of these rice field management systems impacts soil fertility index and rice productivity. This purpose of this research was to know the effect of rice field management systems on soil fertility index and rice productivity in the Madiun Regency. The research uses an explorative descriptive qualitative method with a survey approach. Soil samples were taken using a random sampling method and 3 types of soil management systems (conventional, semi-organic and organic), and rice production samples were taken using an estimation method. The research results show that the soil fertility index ranges from 0.78 to 0.82, which is high. The highest soil fertility index is in the semi-organic management system and the lowest is in the organic management. The management system of semi-organic gave a response to the highest rice production of 6.89 tons/ha. Management system of semi-organic is a better management for increasing and maintaining soil fertility and crop production than conventional or organic. Farming activities results show that organic management systems increase the highest income, increasing 115.58% and 53.30% in semi-organic compared to conventional. The rice field management system has the effect of increasing the worm population density with the highest in the organic system, namely 4.19 individuals m-2. The Pontoscolex worm type dominates the three management systems. There is a correlation between organic matter content and earthworms.

ABSTRACT: The aim of this research was to isolate and characterize bacteria from rice crop soils to determine their prospective biotechnological potential. Therefore, seven morphologically different bacteria were isolated and their physiological characteristics, antimicrobial sensitivity and ability to degrade different substrates were determined. The bacteria grew optimally between 20 and 37 °C, at pH between 5.0 and 10.0. Regarding antimicrobial sensitivity profiles; one, three, one, one, one and one strain showed resistance to 11, 12, 8, 7 and 4 antimicrobials, respectively. Molecular identification was performed by amplification and sequencing of the 16S ribosomal genes, obtaining similarity with the genera Acinetobacter, Bacillus, Staphylococcus, Comamonas and Aeromonas. The bacteria, according to their hydrolytic activity, formed five groups: three degraded gelatin, skim milk, casein, olive oil, starch, cellulose, pectin, and tributyrin; one, olive oil and tributyrin; one, gelatin, skim milk, olive oil and tributyrin; one, gelatin, olive oil, starch, tributyrin; and one, gelatin, skim milk, casein, olive oil and tributyrin. The isolated bacteria show great potential as inoculants for the enrichment and bioremediation of agricultural soils.

RESUMEN: El objetivo de la presente investigación fue aislar y caracterizar bacterias provenientes de suelos de cultivos de arroz para determinar su potencial biotecnológico prospectivo. Para ello, se recolectaron suelos de cultivos de arrozales del distrito de Rioja, Región de San Martín, aislaron siete bacterias morfológicamente diferentes y determinaron sus características fisiológicas, sensibilidad antimicrobiana y capacidad de degradar diferentes sustratos. Las bacterias crecieron óptimamente entre 20 y 37 °C, a pH entre 5,0 y 10,0. Respecto a los perfiles de sensibilidad antimicrobiana; una, tres, una, una y una cepa presentaron resistencia a 11, 12, 8, 7 y 4 antimicrobianos, respectivamente. La identificación molecular se realizó mediante la amplificación y secuenciación de los genes ribosómicos 16S, obteniendo similitud con los géneros Acinetobacter, Bacillus, Staphylococcus, Comamonas y Aeromonas. Las bacterias, según su actividad hidrolítica, formaron cinco grupos: tres degradaron gelatina, leche descremada, caseína, aceite de oliva, almidón, celulosa, pectina, y tributirina; una, aceite de oliva y tributirina; otra, gelatina, leche descremada, aceite de oliva y tributirina; una, gelatina, aceite de oliva, almidón, tributirina; y una, gelatina, leche descremada, caseína, aceite de oliva y tributirina. Las bacterias aisladas presentan gran potencial como inoculantes para el enriquecimiento y la biorremediación de suelos agrícolas.

ABSTRACT: The seedbed phase is decisive in the use of quality seedlings for transplanting. This research aimed to evaluate the differentiated vegetative response of tomato cultivars (Solanum lycopersicum L.) to two substrates under tray conditions. The experiment was carried out at the University of Pinar del Río, Cuba. The cultivars 'Celeste', 'Desquite', 'Grandioso' and 'Radiante' were used in a completely randomized design with factorial arrangement (factors: substrate and cultivar). The substrates were made from Fersialitic soil, organic materials (humus or peat) and rice husks. Sowing was carried out in trays with 40 alveoli (tubes), with a capacity for 70 g of substrate each. The substrates used guaranteed adequate morphophysiological development of tomato seedlings, regardless of the cultivar evaluated, although 'Desquite' presented the lowest absolute growth rate. With the use of the substrate based on soil, humus and rice husk, the number of seedlings useful for transplanting increased by 5%, which guarantees a reduction in the number of trays and volume of substrate used in this phase of crop.

RESUMEN: La fase de semillero es determinante en la utilización de plántulas con calidad para el trasplante. Esta investigación tuvo como objetivo evaluar la respuesta vegetativa diferenciada de cultivares de tomate (Solanum lycopersicum L.) a dos sustratos en condiciones de bandejas. El experimento se ejecutó en la Universidad de Pinar del Río, Cuba. Se utilizaron los cultivares ‘Celeste’, ‘Desquite’, ‘Grandioso’ y ‘Radiante’, en un diseño completamente al azar con arreglo factorial (factores: sustrato y cultivar). Los sustratos se elaboraron a base de suelo Fersialítico, materiales orgánicos (humus o turba) y cascarrilla de arroz. La siembra se realizó en bandejas de 40 alvéolos (tubetes), con capacidad para 70 g de sustrato cada uno. Los sustratos empleados garantizaron un adecuado desarrollo morfofisiológico de las plántulas de tomate, independientemente del cultivar evaluado, aunque ‘Desquite’ presentó la menor tasa absoluta de crecimiento. Con el empleo del sustrato a base de suelo, humus y cascarilla de arroz, se incrementó en 5% las plántulas útiles para el trasplante, lo que garantiza una reducción en el número de bandejas y volumen de sustrato empleados en esta fase del cultivo.

Abstract Climate change poses a significant threat to the agricultural sector around the world, and it could impact the rice crop yields of the Philippines's major rice-producing provinces in Central Luzon; thus, there is a need to investigate the possible influence, both in the near and long term, of climate change on rice crop yields in these major rice-producing provinces. This paper presents the use of random forest, gradient boosting, regression analysis, and artificial neural network (ANN) methods for modeling climate factors (pressure, temperature, relative humidity, rainfall, wind, cloudiness, and sunshine) and rice crop yield (RCY) data from Central Luzon, Philippines, covering the years 2009 to 2018. The projected temperature and rainfall for Representative Concentration Pathways 4.5 and 8.5 (RCP4.5 and RCP8.5, respectively) scenarios were used as input to the models to estimate the possible influence of climate change on the rice crop yields in the rice-producing provinces in Central Luzon. The results suggest an increase in temperature of 1.14 °C in RCP4.5, which surges to 1.62 °C in RCP8.5, and an increase in rainfall by a mean of 3.70 mm in RCP4.5 and 12.28 mm in RCP8.5. Furthermore, three of the models: ANN, random forest (RF), and gradient boosting (GB) showed an increase in RCY, while linear regression (LR) showed a decrease in RCY for both the RCP4.5 and RCP8.5 scenarios compared to the current RCY. Therefore, it is uncertain whether climate change, as characterized by rainfall and temperature, will have a positive or negative impact on rice crop yields in Central Luzon, Philippines.

Resumen El cambio climático representa una amenaza significativa para el sector agrícola en todo el mundo, y podría afectar los rendimientos del cultivo de arroz en las principals provincias productoras de arroz de Filipinas en Luzón Central, por lo que es necesario investigar la posible influencia, tanto a corto como a largo plazo, del cambio climático en los rendimientos del cultivo de arroz en estas principales provincias productoras de arroz. Este artículo presenta el uso de Random Forest, Gradient Boosting, Análisis de Regresión y Redes Neuronales Artificiales (ANN) en la modelización de factores climáticos (presión, temperatura, humedad relativa, lluvia, viento, nubosidad y luz solar) y datos de rendimiento del cultivo de arroz de Luzón Central, Filipinas, que cubren los años 2009 a 2018. Se utilizaron las proyecciones de temperatura y lluvia para los escenarios de Ruta de Concentración Representativa 8.5 y 4.5 (RCP4.5 y 8.5) en los modelos para estimar la posible influencia del cambio climático en los rendimientos del cultivo de arroz en las provincias productoras de arroz de Luzón Central. Los resultados sugieren un aumento de la temperatura de 1,14 °C en RCP4.5, y aumenta a 1,62 °C en RCP8.5; y un aumento en la lluvia en una media de 3,70 mm en RCP4.5 y 12,28 mm en RCP8.5. Además, tres de los modelos (ANN, RF y GB) mostraron un aumento en los rendimientos del cultivo de arroz (RCY), mientras que LR mostró una disminución en RCY; tanto para los escenarios RCP4.5 y 8.5 en comparación con los RCY actuales. El estudio concluye que es incierto si el cambio climático, caracterizado por la lluvia y la temperatura en este estudio, ha tenido un impacto positivo o negativo en los rendimientos del cultivo de arroz semilla.

Abstract Weed control is one of the major challenges in rice production, being the most important agronomic constraint. The apple snail (Pomacea maculata) is the main gastropod pest in rice fields predating rice seedlings in juvenile stages. The purpose of this research is to evaluate the biological use of the apple snail to control weeds in rice. Field trials were carried out to evaluate new techniques of capture and management of the mollusc for optimal weeding of rice fields with different rice cultivation techniques, such as dry seeding, wet seeding and transplanting. Combinations of these techniques are evaluated for their effect on snail control, weed control and effects on rice production, using plots treated with the molluscicide saponin (Camelia sp. seed extract) as a control. In dry sowing, good crop development and a good contribution of apple snails were obtained both when using snail traps (77.4% weed reduction) and when not using them (96.77% reduction). In wet seeding and transplanting, a solid contribution of the apple snail was obtained in the reduction of weeds of 100%; although in transplanting it is necessary to eliminate the snail captured with traps to avoid affecting the rice. The apple snail management is an agroecological alternative for the control of weeds plants, especially in the case of rice.

Resumen El control de malas hierbas es uno de los mayores desafíos en la producción de arroz, siendo la limitación agronómica más importante. El caracol manzana (Pomacea maculata) es la principal plaga de gasterópodos en arrozales depredando las plántulas de arroz en estadios juveniles. El propósito del estudio es evaluar la utilidad del uso del caracol manzana para controlar las malas hierbas en el cultivo del arroz, para ello se realizaron ensayos en los que se evaluó nuevas técnicas de captura y gestión del molusco para el óptimo desherbado de los campos de arroz con distintas técnicas de cultivo, como son la siembra en seco, la siembra en inundación y el trasplante. Las combinaciones de dichas técnicas son evaluadas en cuanto a su efecto tanto en el control del caracol, como en el control de malas hierbas y los efectos sobre la producción del propio arroz, usando como control parcelas tratadas con extracto de saponinas de Camelia sp.. En siembra en seco se obtiene un buen desarrollo del cultivo y una buena aportación de caracol manzana tanto cuando se usan trampas para regular las poblaciones del caracol (reducción de malas hierbas del 77,4%), como cuando no (reducción de 96,77%). Mientras que, en siembra en inundación y trasplante, se obtiene un valor cercano de eliminación del 100% de las malas hierbas. El caracol manzana resulta ser una alternativa agroecológica adecuada para el control de malas hierbas, en especial en siembra en seco y trasplante.

Abstract The golden apple snail (Pomacea canaliculata) (Lamarck) is the pest that has caused the most problems in recent years in rice crops. This pest has significantly reduced the productivity of rice worldwide. The present work was carried out on the Salitre-Baba highway, at km 38 in the province of Guayas, Ecuador 2020. It was an experimental trial at the field level, where different doses were applied (one liter of copper chelate + ozonated water/hectare) and (two liters of copper chelate + ozonated water/hectare). For this, a randomized complete block design (RCBD) and 4 treatments, 1 control, and 4 repetitions were used. Once the rice was harvested, statistical data related to yield were collected. The results show that the yield is not affected by the application of copper chelate and ozone and although there was no significant difference between all treatments, it was observed that the best treatment was T4, which corresponds to the dose of 2 L ha-1 of copper chelate mixed with ozonated water with 2 ppm concentration, where the yield was 3 827.5 ±877.8 kg ha-1, higher compared to T5 (control), which reflected a yield of 1 488.7 ±596.4 kg ha-1 significantly lower due to the presence and effects of the snail. It was concluded that copper chelate with ozonated water can control the golden apple snail in rice crops, and an increase in grain yield was observed.

Resumen El caracol manzana (Pomacea canaliculata) (Lamarck) es la plaga que más problemas ha causado en los últimos años en los cultivos de arroz. Esta plaga ha reducido significativamente la productividad del arroz en todo el mundo. El presente trabajo se realizó en vía Salitre-Baba, en el km 38 en la provincia del Guayas, Ecuador 2020. Fue un ensayo experimental a nivel de campo donde se aplicaron diferentes dosis (un litro de quelato de cobre + agua ozonizada/hectárea) y (dos litros de quelato de cobre + agua ozonizada/hectárea). Para lo cual se utilizó un diseño de bloque completo al azar (DBCA) y 4 tratamientos, 1 testigo y 4 repeticiones. Una vez cosechado el arroz, los datos estadísticos relacionados con el rendimiento fueron recolectados. Los resultados demuestran que el rendimiento no se ve afectado por la aplicación de quelato de cobre y ozono y aunque no hubo diferencia significativa entre todos los tratamientos se observó que el mejor tratamiento fue el T4, que corresponde a la dosis de 2 L ha-1 de quelato de cobre mezclado con agua ozonizada con 2 ppm de concentración donde el rendimiento fue de 3 827.5 ±877.8 kg ha-1, mayor comparado con el T5 (testigo) que reflejo un rendimiento de 1 488.7 ±596.4 kg ha-1 significativamente inferior por la presencia y efectos del caracol. Se concluyó que el quelato de cobre con el agua ozonizada puede controlar el caracol manzana en el cultivo del arroz, además se observó un aumento de rendimiento en el grano.

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 The crop-livestock farming system in paddy fields is integrated between rice crops and beef cattle (rice-beef cattle CLFS). Rice plants will produce straw and rice bran that can be used for animal feed, and livestock will produce compost/manure that can be used for rice nutrition. Some other benefits of implementing CLFS are increasing crop productivity, increasing the value of farmers' income, farming cost efficiency, and preserving the environment. The probability of the sustainability of CLFS application in paddy fields can be measured by calculating the system proximity index ratio using the SPIR formula. This research aims to demonstrate the accuracy of the SPIR formula in predicting the probability of CLFS sustainability in paddy fields. This study compares CLFS programs in several regions in Indonesia. It uses an independent sample t-test analysis tool with one-way rejection criteria to see the difference in SPIR scores on sustainable and unsustainable CLFS. The results showed that the SPIR formula could predict the sustainability of the CLFS program in Indonesia. However, further studies are needed to prove its ability to predict CLFS sustainability in other parts of the world. croplivestock ricebeef . CLFS) feed compostmanure compost manure nutrition productivity farmers income efficiency environment Indonesia ttest t test oneway one way However world

Resumen El sistema agrícola en cultivos de arroz es un sistema integrado entre cultivos de arroz y ganado vacuno (arroz-vacuno CLFS). Las plantas de arroz producirán paja y salvado de arroz que se pueden usar como alimento para animales, y el ganado producirá compost/estiércol que se puede usar para la nutrición del arroz. Algunos de los otros beneficios de implementar CLFS son el aumento de la productividad de los cultivos, el aumento del valor de los ingresos de los agricultores, la eficiencia de los costos agrícolas y la preservación del medio ambiente. La probabilidad de sostenibilidad de la aplicación de CLFS en los campos de arroz se puede medir calculando la relación del índice de proximidad del sistema utilizando la fórmula SPIR. El objetivo de esta investigación es demostrar la precisión de la fórmula SPIR para predecir la probabilidad de sostenibilidad de CLFS en arrozales. Este estudio compara los programas CLFS en varias regiones de Indonesia y utiliza una herramienta de análisis de prueba t de muestra independiente con criterios de rechazo unidireccionales para ver la diferencia en las puntuaciones SPIR en CLFS sostenible e insostenible. Los resultados mostraron que la fórmula SPIR puede predecir la sostenibilidad del programa CLFS en Indonesia. Sin embargo, se necesitan más estudios para demostrar su capacidad para predecir la sostenibilidad de CLFS en otras partes del mundo. arrozvacuno CLFS. . CLFS) animales compostestiércol compost estiércol agricultores ambiente arrozales insostenible embargo mundo

ABSTRACT Rice (Oryza sativa) is among the most important crops worldwide; however, rice crops demand high water consumption. Future projections indicate reduced water availability and severe drought events, which may affect rice crops as the cereal is highly sensitive to drought stress. Thus, cultivars with lower water demand for irrigation or drought escape capacities are among the strategies to address this issue. This study aimed to assess five mutant rice genotypes in terms of growth cycle length, other agronomic interest traits, and drought response in the reproductive stage. The mutant genotypes evaluated showed a shortening of the growth cycle compared to the original cultivar, BRS Pampeira, representing a drought escape strategy. In addition, mutations did not negatively affect plant height and crop yield. However, similar to the original cultivar, mutants are not tolerant to water deficit in the reproductive stage. The genotypes evaluated have potential to be released as early cycle cultivars, which can reduce water demand during the harvest season while presenting a drought escape strategy. Oryza sativa worldwide however consumption events stress Thus issue length traits stage cultivar Pampeira strategy addition yield However