Made available in DSpace on 2016-04-28T14:58:33Z (GMT). No. of bitstreams: 1 2007- Marcio Emanoel de Lima.pdf: 716082 bytes, checksum: 776f00d9f4cf02d4e31b2cbd8d2f14ab (MD5) Previous issue date: 2007-02-28 / The present work had like objective study the effect of different levels of irrigation handled on the basis of the evaporation of the tank Class TO in the growth and performance of the lettuce (Lactuca sativa) cultivated in different epochs of the year in soil with and without utilization of dead cover. They were driven two series of experiments evaluating the effect of different levels of water in the first phase they determined itself the growth rates of the culture and in the second one evaluated the performance of the lettuce cultivated in a soil with and without utilization of dead cover. Both the series were carried out in the experimental area of the SIPA (System Integrated of output Agroecol?gica), located in the town of Serop?dica-Rio de Janeiro. The experimental delineation adopted in the first essay was in randomized blocks, with 5 handlings (25, 50, 80, 100 and 115% of the evapotranspira??o of the culture - ETc) and four repetitions, totalling up 20 experimental units containing 44 plants by installment. They were carried out collections of the plants during the cycle of the culture to the 10, 16, 22, 28 and 32 days after transplant (DAT), with an aim to determine the growth rates of them plants by the functional approach, being analyzed the variables area foliar and batter drought of the plants. To the 32 DAT was characterized the productivity of the culture by the analysis of the variables area foliar, fresh batter, number of sheets and diameter of the head. The culture presented a slow growth to the cultivation day 22o, being observed, from this date, a bigger accumulation of biomassa and increase of area foliar. The handling that replaced a sheet of 80% ETc provided a better performance of the culture regarding the productivity in all the variables analyzed, but was not possible observe significant differences between the handlings, due to humidity of soil to remain homogeneous during the conduction of the experiment. In the second phase, were driven two simultaneous experiments, being applied 5 levels of irrigation (25, 50, 80, 100 and 115% ETc), in two conditions of cover of him soil: soil n? and soil covered with straw of leguminous plant gliric?dia (Gliricidia sepium). The delineation adopted was in randomized blocks, with 5 handlings (sheets of irrigation) and 4 repetitions. After it attend all the of the statistical viewpoint, was carried out a joint analysis of the facts, with regression for the irrigation level variable, and test F for the variable dead cover. For the variables analyzed, in the system of plantation with dead cover had an increase in the area foliar, fresh batter and number of sheets to the level of 100% ETc and for the level of 115%, had a decrescimento of the same, due to the excess of humidity. Utilizing the equations adjusted, the maximum values of the variables studied were observed in the break of the sheets of irrigation 80 and 100% of the ETc. In the system of plantation without dead cover, the levels of irrigation analyzed were not sufficient for manifest the maximum performance of the culture. In the joint analysis for the variable fresh batter, the system of cultivation with utilization of dead cover was over the without cover differentiating estatisticamente level with 5% probability by the test F. Only not they were observed statistical differences between the corresponding sheets to 25 and 115% ETc, showing that only the utilization of dead cover is not sufficient for obtaining of better productivity. / O presente trabalho teve como objetivo estudar o efeito de diferentes n?veis de irriga??o manejada com base na evapora??o do tanque Classe A no crescimento e desempenho da alface (Lactuca sativa) cultivada em diferentes ?pocas do ano em solo com e sem utiliza??o de cobertura morta. Foram conduzidas duas s?ries de experimentos avaliando o efeito de diferentes n?veis de ?gua, na primeira etapa determinaram-se as taxas de crescimento da cultura e na segunda avaliou o desempenho da alface cultivada em um solo com e sem utiliza??o de cobertura morta. Ambas as s?ries foram realizadas na ?rea experimental do SIPA (Sistema Integrado de produ??o Agroecol?gica), localizado no munic?pio de Serop?dica-RJ. O delineamento experimental adotado no primeiro ensaio foi de blocos casualizados, com 5 tratamentos (25, 50, 80, 100 e 115 % da evapotranspira??o da cultura - ETc) e quatro repeti??es, totalizando 20 unidades experimentais contendo 44 plantas por parcela. Foram realizadas coletas das plantas durante o ciclo da cultura aos 10, 16, 22, 28 e 32 dias ap?s transplantio (DAT), com vista a determinar as taxas de crescimento das plantas pelo m?todo funcional, sendo analisadas as vari?veis ?rea foliar e massa seca das plantas. Aos 32 DAT foi caracterizada a produtividade da cultura pela an?lise das vari?veis ?rea foliar, massa fresca, n?mero de folhas e di?metro da cabe?a. A cultura apresentou um crescimento lento at? o 22o dia de cultivo, sendo observado, a partir desta data, um maior ac?mulo de biomassa e aumento de ?rea foliar. O tratamento que repunha uma l?mina de 80% ETc proporcionou um melhor desempenho da cultura em rela??o ? produtividade em todas as vari?veis analisadas, mas n?o foi poss?vel observar diferen?as significativas entre os tratamentos, devido a umidade do solo permanecer homogenia durante a condu??o do experimento. Na segunda etapa, foram conduzidos dois experimentos simult?neos, sendo aplicados 5 n?veis de irriga??o (25, 50, 80, 100 e 115 % ETc), em duas condi??es de cobertura do solo: solo n? e solo coberto com palha de leguminosa gliric?dia (Gliricidia sepium). O delineamento adotado foi de blocos casualizados, com 5 tratamentos (l?minas de irriga??o) e 4 repeti??es. Ap?s atender todas as pressuposi??es do ponto de vistas estat?stico, foi realizada uma an?lise conjunta dos dados, com regress?o para a vari?vel n?vel de irriga??o, e teste F para a vari?vel cobertura morta. Para as vari?veis analisadas, no sistema de plantio com cobertura morta houve um aumento na ?rea foliar, massa fresca e n?mero de folhas at? o n?vel de 100 % ETc e para o n?vel de 115%, houve um decrescimento das mesmas, devido ao excesso de umidade. Utilizando as equa??es ajustadas, os valores m?ximos das vari?veis estudadas foram observados no intervalo das l?minas de irriga??o 80 e 100 % da ETc. No sistema de plantio sem cobertura morta, os n?veis de irriga??o analisados n?o foram suficientes para manifestar o m?ximo rendimento da cultura. Na an?lise conjunta para a vari?vel massa fresca, o sistema de cultivo com utiliza??o de cobertura morta foi superior ao sem cobertura diferenciando estatisticamente ao n?vel de 5 % probabilidade pelo teste F. Somente n?o foram observadas diferen?as estat?sticas entre as l?minas correspondentes a 25 e 115 % ETc, demonstrando que somente a utiliza??o de cobertura morta n?o ? suficiente para obten??o de melhores produtividades.