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Sugarcane harvesting requires improvements, particularly in cutting tools. Continuous cutting saws have been introduced as a solution to this issue. This study evaluates the performance of two basal sugarcane cutting systems in different fields: a traditional impact cut system (ICS) with knives and a continuous cut system (CCS) with saw blades. Tests were conducted during two crop cycles in three areas, using a 3 × 2 factorial design with two cutting devices and four replications per treatment. Cut quality indices and ratoon damage were analyzed using descriptive statistics. Raw material losses were subjected to the Shapiro–Wilk normality test, ANOVA, and Tukey’s test at 5% probability. Significant differences in cutting quality were found across different areas. The total crop productivity influenced sugarcane cut quality, with the CCS showing (0.8 Mg ha−1) visible losses in higher productivity areas, which is a 74% increase compared to the ICS. In lower productivity areas, the CCS demonstrated better loss performance (0.8 Mg ha−1). Additionally, the stumps damage rate for the CCS was lower than that for the ICS (0.15 and 0.28, respectively), indicating that saws can preserve cane fields and enhance longevity.

Made available in DSpace on 2022-05-01T16:48:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Sugarcane is one of the most important agricultural crops in the Brazilian trade economics, however, this crop presents challenges in maintaining the physical structure of the soil throughout the production cycle. The ground cover has a direct interference in the compaction processes. However, the amount to be kept in the field remains a difficult to discover unknown. The aim of this study was to evaluate the tread–soil interaction and penetration resistance provided by 600/50–22.5 bias-ply agricultural tire, under three different amounts of straw on the surface: 0, 15 and 30 Mg ha−1. The tests were carried out at the Nempa Center Testing of Agroforestry Machines and Tires, UNESP/Botucatu–SP. The Fixed Tire Testing Unit was used, applying a constant and controlled load to the tire on standardized soil with different amounts of straw on the surface. The response to variables analyzed was the settlement contact area and the resistance soil penetration (RSP). The findings of the study showed that amount of straw on the ground attenuates the impact of wheelset on the soil and linearly increases the area of wheelhouse–soil interaction (r2 = 0.98), contact width (r2 = 0.97), contact length (r2 = 0.86) and depth (r2 = 0.99). The RSP is linearly inverse (r2 = 0.97) to the amount of straw in the covering, where 15 Mg ha−1 was found adequate to maintain soil quality due to machine traffic under the conditions analyzed. Rural Engineering and Agricultural Mechanization Department College of Agricultural Sciences São Paulo State University - UNESP, Av. Universitária, 3780, SP Statistic and Informatic Department Technological Center University of Santa Catarina - UFSC, Bairro Trindade, SC Cassilândia University Unit Agronomy Department Mato Grosso Do Sul State University - UEMS, 306 Road, Km 6, Mato Grosso do Sul Rural Engineering and Agricultural Mechanization Department College of Agricultural Sciences São Paulo State University - UNESP, Av. Universitária, 3780, SP

Soil compaction is one of the great obstacles in modern agriculture. With the increase in size, weight and intensity of use of machines in crops in recent decades, the soil has suffered damage to its structure, compromising the productivity of vegetable crops. One of the ways to indirectly obtain the compaction state of the soil is through the resistance to penetration imposed by it on a standardized metal rod. Invariably, commercial equipment for this purpose is expensive. The objective of this study was to develop a low-cost system for evaluating the resistance to soil penetration, using a prototyping platform and specific sensors. The developed equipment, when compared with a calibrated standard equipment, presented a high correlation in the results of resistance to penetration in two soil conditions. The development cost of the proposed equipment was 800% lower than the average value of commercial equipment available on the market, so the measurements met the purpose of the project, showing the possibility of developing low-cost solutions through prototyping platforms, for the assessment of resistance to soil penetration. Soil compaction is one of the great obstacles in modern agriculture. With the increase in size, weight and intensity of use of machines in crops in recent decades, the soil has suffered damage to its structure, compromising the productivity of vegetable crops. One of the ways to indirectly obtain the compaction state of the soil is through the resistance to penetration imposed by it on a standardized metal rod. Invariably, commercial equipment for this purpose is expensive. The objective of this study was to develop a low-cost system for evaluating the resistance to soil penetration, using a prototyping platform and specific sensors. The developed equipment, when compared with a calibrated standard equipment, presented a high correlation in the results of resistance to penetration in two soil conditions. The development cost of the proposed equipment was 800% lower than the average value of commercial equipment available on the market, so the measurements met the purpose of the project, showing the possibility of developing low-cost solutions through prototyping platforms, for the assessment of resistance to soil penetration.

Constant exposure to high noise levels can cause health problems for agricultural machinery operators. Machines equipped with closed cabs can attenuate noise and preserve the operator from an unhealthy condition. Some studies show that in cabin tractors it is possible to renounce the use of hearing protection, however indoor equipment and air conditioning can reach high levels of noise, which need to be further investigated. The present study aimed to evaluate the noise emitted by a cabined agricultural tractor, in different points, inside and outside cabin, in the engine rotations of 800rpm, 2180rpm and 2500rpm. In each reading, 100 noise intensity values were automatically collected, over two minutes with the aid of a digital decibel meter device. The results were compared with the levels assumed by Annex 1 of the regulatory Brazilian standard NR 15, and it was found that the cabin was able to isolate the noise emitted by the engine and its external components in 15%, however, the internal noise reached 81dB(A). The cabin can attenuate external noise and offer a healthy working environment, however, in long working hours it is recommended to use personal protective equipment such as ear protectors.

A coleta de dados e o monitoramento ambiental na agricultura são atividades de alta complexidade, demandando normalmente equipamentos de alto custo. A coleta de dados deve ser realizada preferivelmente próxima ao estrato das culturas vegetais, pois desta forma obtém-se dados fidedignos do microambiente ao qual a planta está inserida. Objetivou-se desenvolver um sistema de coleta de dados, de baixo custo, para a obtenção de parâmetros relacionados à luminosidade, umidade do solo, umidade do ar e temperatura em ambiente agrícola. Utilizou-se a metodologia específica de desenvolvimento de produtos e, plataforma de prototipagem Arduino para montagem do sistema Datalogger. Foram realizados testes de funcionamento em duas casas de vegetação A1 e A2 pelo período de 24 horas. A concepção do sistema, com a utilização de suportes de sensores, permitiu a coleta de dados sem interrupção e com adequada acurácea. A plataforma Arduíno e sensores acessórios mostraram-se perfeitamente aplicáveis para a aquisição e armazenamento de dados em casas de vegetação. O protótipo de Datalogger desenvolvido apresentou redução de custo de 600 até 3000% em relação aos componentes disponíveis no mercado com funcionalidades semelhantes.

O FORMATO DAS SEMENTES PODE INFLUENCIAR A PLANTABILIDADE DO MILHO EM DOSADORES PNEUMÁTICOS? JÚLIO CÉSAR SANTOS PEREIRA1, ALDIR CARPES MARQUES FILHO1, GUINTHER HUGO GRUDTNER2, PAULO ROBERTO ARBEX SILVA1 1 Departamento de Engenharia Rural, Universidade Estadual Paulista, UNESP/Botucatu, av. Universitária, 3780, Altos do Paraíso, 18610-034, Botucatu, São Paulo, Brasil - julio.spereira@outlook.com; aldir.marques@gmail.com; paulo.arbex@unesp.br 2 Departamento de Engenharia Rural, Universidade Federal de Santa Catarina, UFSC/Florianópolis, Rod. Admar Gonzaga, 1346, Itacorubi, 88034-000, Florianópolis, Santa Catarina, Brasil - guinther_grudtner@hotmail.com RESUMO: A cultura do milho (Zea mays L.) apresenta grande importância econômica para o agronegócio brasileiro. As sementes de milho apresentam características distintas em formato e massa específica de acordo com a cultivar e o local de formação da semente na espiga. O objetivo do presente trabalho foi avaliar a influência do formato de sementes de milho, na qualidade da distribuição longitudinal, com o uso de dosador do tipo pneumático. O presente trabalho foi realizado no Núcleo de Ensaios de Máquinas e Pneus Agroflorestais (NEMPA), pertencente à Faculdade de Ciências Agronômicas, da Universidade Estadual Paulista (UNESP), no município de Botucatu-SP. Foram utilizadas sementes de três híbridos comerciais de milho, em que se avaliou o formato e índice de esfericidade. O delineamento experimental utilizado foi o inteiramente casualizado (DIC), totalizando 15 tratamentos, compostos pelos três híbridos comerciais e cinco pressões de vácuo no dosador. Os resultados demonstraram que o formato de sementes pode influenciar a deposição longitudinal pelo dosador pneumático. Os melhores resultados de deposição de sementes foram obtidos com o híbrido V3, de formato arredondado, estas apresentaram maior índice de espaçamentos aceitáveis, menor ocorrência de falhas e duplas. A pressão de vácuo de 7kPa propiciou 98% de espaçamentos aceitáveis para o híbrido V3. Para os híbridos V1 e V2, as pressões de 4kPa e 3kPa, demonstraram respectivamente 96% e 87% de espaçamentos aceitáveis. Palavras-chave: semeadura, esfericidade, pressão de vácuo, espaçamento. CAN THE SEED FORMAT INFLUENCE THE PLANTABILITY OF MAIZE IN PNEUMATIC DOSERS? ABSTRACT: Corn (Zea mays L.) is of great economic importance for Brazilian agribusiness. Corn seeds have different characteristics in shape and specific mass according to the cultivar and place of seed formation on the corn cob. This research aimed to evaluate the influence of the shape of corn seeds, in the longitudinal distribution, with the use of a pneumatic doser. This study was conducted at the Agroforestry Machinery and Tire Testing Center (NEMPA), belonging to the Faculty of Agronomic Sciences, of the University State of São Paulo (UNESP), in the municipality of Botucatu-SP. Seeds from three commercial corn hybrids were used, in which the shape and sphericity index were evaluated. The experimental design used was completely randomized (DIC), totaling 15 treatments, composed of three varieties of corn, and five vacuum pressures in the doser. Our findings demonstrated that the seed shape influences the longitudinal deposition by the pneumatic feeder. The best results of seed deposition were obtained using the rounded V3 hybrid, which presented a higher index of acceptable spacing, less occurrence of flaws and doubles. The vacuum pressure of 7 kPa provided 98% of acceptable spacing for the V3 hybrid. For the V1 and V2 hybrids, the pressures of 4 kPa and 3 kPa demonstrated 96% and 87% of acceptable spacing, respectively. Keywords: physical characteristics, sphericity, vacuum pressure, spacing.

PLANTABILIDADE E DISTRIBUIÇÃO LONGITUDINAL DE SEMENTES DE ALGODÃO COM DIFERENTES CONJUNTOS DISCO-ANEL EM DOSADOR MECÂNICO ALDIR CARPES MARQUES FILHO1, LUIZ HENRIQUE MENCK RUSCONI1, PAULO ROBERTO ARBEX SILVA1 1 Departamento de Engenharia Rural, Universidade Estadual Paulista, UNESP/Botucatu, av. Universitária, 3780, Altos do Paraíso, 18610-034, Botucatu, São Paulo, Brasil) aldir.marques@gmail.com; luizhmenck@gmail.com; paulo.arbex@unesp.br RESUMO: A tecnologia em semeadura ou “plantabilidade” é um tema bastante abordado na atualidade e representa a adoção de boas práticas na implantação de lavouras agrícolas. Entre diversos fatores que afetam a qualidade de semeadura está a escolha do conjunto disco e anel dosadores de sementes, como fator de interferência direta na distribuição longitudinal das plantas. Este trabalho teve como objetivo avaliar a interferência da aplicação de dois conjuntos disco-anel de tamanhos diferentes na distribuição longitudinal das sementes na cultura do algodão. O ensaio foi realizado em sistema simulador de semeadura, pertencente ao Núcleo de Ensaios de Máquinas e Pneus Agroflorestais, no Grupo de Plantio Direto (GPD) da UNESP/Botucatu. Os resultados do trabalho mostraram que a seleção adequada do conjunto disco-anel afeta a qualidade da semeadura, sendo que o tratamento T2 apresentou acréscimo de 5% nas falhas e redução de 1% em espaçamentos aceitáveis para a cultura do algodão em semeadura mecânica, assim o percentual de falhas representou um total de 5500 falhas de deposição na lavoura por cada hectare de cultivo. Recomenda-se o uso do conjunto disco-anel T1 (6mm) por ter apresentado os melhores resultados para a variedade de sementes utilizada no experimento. Palavras-chave: mecanização, tecnologia em semeadura, Gossypium hirsutum L. PLANTABILITY AND LONGITUDINAL DISTRIBUTION OF COTTON SEEDS WITH DIFERENTS DISC - RING SET IN MECHANICAL DOSER ABSTRACT: Sowing technology, or “Plantability” is a topic that is widely discussed today and represents the adoption of good practices in the implantation of agricultural crops. Among several factors that affect the quality of planting, the choice of the disc/ring set directly interferes in the longitudinal distribution of plants. This work aimed to evaluate the interference of the application of two disc / ring sets of different sizes in the longitudinal distribution of seeds in cotton crop. Test carried out in a sowing simulator system belonging to the Agroforestry Machinery and Tire Testing Center and the no tillage group (GPD), UNESP/Botucatu. The results of our research showed that the correct selection of the disk-ring set affects the quality of the sowing, and the T2 treatment showed an increase of 5% in the failures and a reduction of 1% in acceptable spacing for the cotton culture in mechanical sowing, as well as the percentage of failures represented 5500 failures of deposition in the field for each hectare of cultivation. It is recommended to use the T1 disk-ring set (6mm) as it has shown the best results for the variety of seeds used in the experiment. Keywords: mechanization, sowing technology, Gossypium hirsutum L

Made available in DSpace on 2022-04-28T19:51:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 In sowing operation, it is essential to control the factors that can affect the quality of seed and fertilizer deposition. These factors range from the correct choice of dosing mechanisms to machine regulation and operating speed control. The present research aimed to analyze the influence of sowing speed on the productive performance of the corn crop. The study was carried out at Fazenda São Geraldo, in the municipality of Boracéia, São Paulo. Four operating speeds 3, 5, 7 and 9 km h-1 were applied in a seeder, with a mechanical horizontal seed meter. The experimental design was carried out in strips. The results showed that sowing operational speed directly influences the final corn yield. There is a positive correlation between sowing speed and reduction in seedling emergence. The speed of 3.0 kmh-1 showed the best results for seed deposition and yield. The speeds of 5, 7 and 9 km h -1 presented a reduction of 14.8, 42.5 and 67.2 bags per hectare. Universidade Estadual Paulista Júlio de Mesquita Filho Campus Botucatu, São Paulo Faculdades Integradas de Bauru, Bauru, São Paulo Universidade Estadual Paulista Júlio de Mesquita Filho Campus Botucatu, São Paulo

Machine tests are standardized procedures that aim to present reliable and impartial information of the evaluated machines. The agricultural tractor is the main source of power in the agricultural setting. Therefore, to acquire an in-depth knowledge of the operational and performance characteristics of these machines, a tractor test is necessary as this will help in achieving higher yields in the field. Performance of tests of tractors and agricultural machinery is usually the responsibility of the manufacturers, official government agencies, and research institutions. New machines and technologies are being developed; therefore, information on the current status of tractor testing and the procedures and advances in the methodologies used for the evaluation of machines is fundamental in today’s agriculture 4.0. This review aims to examine the current state of agricultural tractor testing worldwide, with special focus on that in Brazil. Agriculture 4.0, or intelligent agriculture, incorporates new and advanced resources, such as computers, sensors, and actuators, which are used in operational performance and efficiency testing, thus contributing to the modernization of technology and improvement of machines. New methods of performance assessment and data collection are under consideration and should be established through clear and specific standards. RESUMO Os ensaios de máquinas em geral são procedimentos padronizados que objetivam apresentar informações confiáveis e imparciais a respeito dos espécimes avaliados. O trator agrícola é a principal fonte de potência no meio agrícola e os ensaios de tratores permitem conhecer profundamente as características construtivas dessa máquina, conferindo a estes maiores rendimentos no campo. A realização de ensaios em tratores e máquinas agrícolas normalmente é de responsabilidade de órgãos governamentais oficiais ou instituições de pesquisa, além dos próprios fabricantes. Novas máquinas e tecnologias estão sendo desenvolvidas e, conhecer a situação atual dos ensaios de tratores, detalhar seus procedimentos e avançar na elaboração de metodologias voltadas para avaliação de máquinas é fundamental na atual agricultura 4.0. Esta revisão buscou apresentar o estado da arte na realização de ensaios com tratores agrícolas no mundo e, particularmente, no Brasil. A agricultura 4.0 ou agricultura inteligente, incorpora novos e avançados recursos, tais como a computação embarcada, os sensores e os atuadores aos ensaios de desempenho operacional e de eficiência, contribuindo assim com a modernização da tecnologia e o aprimoramento das máquinas. Novas formas de avaliação do desempenho e coleta de dados estão latentes e precisam ser estabelecidas através de normas claras e específicas.

Made available in DSpace on 2022-04-28T19:51:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Brazil stands out among the world's largest soy producers.The uniformity in the deposition of seeds and the correct distribution of plants are important factors for the crop to express its maximum productive potential. The present study aimed to evaluate the influence of the lubricant agent “graphite”, applied during and after the chemical treatment ofsoybean seeds in function ofits longitudinal distribution at different operating speeds.Forthis purpose, a seeder with mechanical type feeder was used, at three working speeds: 4, 6 and 8 km h-1 and conducted in a strip design, organized in a 2x3 factorial scheme, with two different modes of application of graphite and 3 operating speeds. The results presented showed that the addition of graphite concomitantly with the seed treatment,increases the unevenness of sowing, the same occurs in relation to the increase in the speed of operation. Graphite loses lubricating action when added to the seed treatment, increasing the number of failures. Universidade Estadual Paulista Júlio de Mesquita Filho Câmpus de Botucatu, São Paulo Universidade Estadual Paulista Júlio de Mesquita Filho Câmpus de Botucatu, São Paulo

AVALIAÇÃO DO DESEMPENHO DE UMA PLANTADORA DE MANDIOCA SOB SISTEMA DE PLANTIO DIRETO TRACIONADA POR TRATOR DE RABIÇAS ALBERTO KASUSHI NAGAOKA1, FERNANDO CÉSAR BAUER2, GUINTHER HUGO GRUDTNER3, ALDIR CARPES MARQUES FILHO4, NUNO CAMPOS FILHO5 1 Departamento de Engenharia Rural, Centro de Ciências Agrárias, UFSC, (Rua Admar Gonzaga, 1346 –Itacorubi, Florianópolis, 88034-000), alberto.nagaoka@ufsc.br 2 Departamento de Engenharia Rural, Centro de Ciências Agrárias, UFSC, (Rua Admar Gonzaga, 1346 –Itacorubi, Florianópolis, 88034-000), Fernando.bauer@ufsc.br 3 Departamento de Engenharia Rural, Centro de Ciências Agrárias, UFSC, (Rua Admar Gonzaga, 1346 –Itacorubi, Florianópolis-SC, 88034-000), guinther_grudtner@hotmail.com 4 Departamento de Engenharia Rural, Universidade Estadual Paulista, UNESP, (Rua José Barbosa de Barros, 1780, Jd. Paraíso- Botucatu-SP, 18610-034), aldir.marques@gmail.com 5 Departamento de Engenharia Rural, Centro de Ciências Agrárias, UFSC, (Rua Admar Gonzaga, 1346 –Itacorubi, Florianópolis, 88034-000), nuno.campos@ufsc.br RESUMO: A produção de mandioca possui grande importância nas regiões onde predomina a agricultura familiar em pequenas propriedades rurais, assim a mecanização do cultivo pode promover o incremento de produtividade e otimizar o rendimento operacional. O objetivo deste trabalho foi avaliar o desempenho de uma plantadora de mandioca em sistema de plantio direto, tracionada por um trator de rabiças, através de dois ensaios de campo. No primeiro ensaio a plantadora foi avaliada em função de três velocidades distintas, obtendo dados de potência exigida pelo conjunto trator-plantadora e por cada parte constituinte da máquina. No segundo ensaio, avaliou-se a plantadora sob duas velocidades, dois modelos de discos de corte, dois modelos de rodas compactadoras e a potência exigida para tracioná-la, além da distribuição longitudinal das plantas de mandioca. Os resultados do primeiro ensaio mostraram que a marcha de menor velocidade exigiu menor potência do trator. Já os resultados do segundo ensaio, demonstraram que a potência exigida do trator variou em função do tipo de disco de corte e de roda compactadora da plantadora. Para a avaliação da distribuição longitudinal, a plantadora avaliada não apresentou diferenças estatísticas na percentagem de espaçamentos aceitáveis, falhos e duplos entre as linhas de plantio. Palavras-chave: manihot esculenta crantz, mecanização, máquina. EVALUATION OF PERFORMANCE OF CASSAVA IN NO TILLAGE, WITH TRACTOR OF HANDLEBARS ABSTRACT: Cassava production is one of the greatest important in regions where family agriculture and small farms are predominant. The aim of this research was to evaluate the performance of a no-till cassava planter traced by a tractor of handlebar, through two field trials. In the first trial the planter was evaluated according to three speeds, obtaining data of power required by the tractor-planter assembly and each constituent part of the planter. In the second test, the planter was evaluated under two speeds, two models of cutting discs, two models of compacting wheels and the power required drawing it, besides the longitudinal distribution of cassava. The results of the first test showed that lower speed gear required less tractor power. The results of the second test, however, showed that the required power of the tractor varied according to the type of cutting disc and the compactor wheel of the planter. For the evaluation of longitudinal distribution, the planter evaluated did not present statistical differences in the percentage of acceptable, faulty and double spacing between the planting lines. Keywords: manihot esculenta crantz, mechanization, machine.

A racionalizacao no aproveitamento de recursos energeticos e fundamental em todos os setores da agricultura. O conhecimento relacionado ao controle micro ambiental em casas de vegetacao requer mao de obra qualificada, o que e um entrave em muitas regioes do Brasil. Objetivou-se com o presente trabalho, desenvolver um sistema eletronico para controle microclimatico interno em casas de vegetacao, com o diferencial de possuir em sua programacao, algoritmos relacionados a fisiologia dos vegetais, bem como verificar se o sistema de controle afeta a produtividade da cultura da alface “lactuca sativa”. O sistema de controle foi desenvolvido tendo como base a plataforma de prototipagem Arduino™ Mega 2560 e transdutores compativeis. O software de funcionamento foi desenvolvido em linguagem C/C++, contendo informacoes relativas ao estadio fenologico da cultura vegetal, e proporcionando atraves de atuadores condicoes ideais de temperatura, umidade relativa do ar, umidade do solo e radiacao global. Foi realizada uma analise experimental a campo ao longo de um ciclo produtivo para duas variedades de alface. Os resultados experimentais apontaram que equipamento projetado funcionou de acordo com o algoritmo de programacao implementado, controlou corretamente os atuadores e incrementou em 26.7% a produtividade da alface tipo Americana e 29% a produtividade da alface tipo crespa

Made available in DSpace on 2021-06-25T11:05:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Sugarcane is highlighted in Brazilian agribusiness; however, some operations must be investigated from a technical and economic point of view, such as harvesting. The objective of this work was to estimate the cost of a sugarcane harvester as a function of its operational performance. The experiment was carried out in a sugar and alcohol unit in Tietê-SP/Brazil. The harvest occurred without prior burning of sugarcane field, in an area with an estimated productivity of 92.5 Mg ha−1. The operational and energetic performance of the machine were evaluated and the cost of operation at three working speeds (3.0, 5.0 and 7.0 km h−1) was estimated. It was observed that the work speed is related to the operational costs, volumetric fuel consumption accounted for 41–49% of total operation costs, while depreciation of the machine accounted for 14–17%, and repair and maintenance costs 11–14%. Results showed that the average speed of 7 km h−1 was the one that presented the best economic performance in harvesting operation. Travel speeds significantly affected the operational performance of sugarcane harvester and showed a positive correlation with volumetric fuel consumption. Field capacity and variable costs were proportional to the working speeds. The biggest impact on harvester costs were the volumetric fuel consumption, the depreciation of the agricultural machine and the costs with repairs and maintenance of the harvester. Agronomy Department Mato Grosso do Sul State University – UEMS Cassilândia University Unit, 306 Road, Km 6 Rural Engineering and Socioeconomics Department College of Agricultural Sciences UNESP – São Paulo State University, Av. Universitária, 3780 Rural Engineering and Socioeconomics Department College of Agricultural Sciences UNESP – São Paulo State University, Av. Universitária, 3780

Made available in DSpace on 2021-06-25T11:20:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 The objective of this study was to develop an electronic controller for microclimate control in greenhouses, as well as to verify if the automated control system affects the productivity of two varieties of lettuce Lactuca sativa. The control system was developed based on the Atmega 2560 and compatible transducers. An experimental field analysis was carried out over a production cycle for two lettuce varieties. The experimental results showed that the designed equipment worked according to the implemented programming algorithm. However, the ventilation, nebulization and shading actuators did not control environmental variables, due to under sizing. The irrigation process was correctly controlled throughout the experimental period. The electronic controller promoted increase in the productivity of lettuce varieties. There was increase of 28% in total fresh weight; 10% in stem diameter; 7 and 8% in height gain and average diameter, respectively. Univ Estadual Paulista, Campus Botucatu, Botucatu, SP, Brazil Inst Fed Santa Catarina, Campus Florianopolis, Florianopolis, SC, Brazil Univ Fed Santa Catarina, Campus Florianopolis, Florianopolis, SC, Brazil Univ Estadual Paulista, Campus Botucatu, Botucatu, SP, Brazil