Diagnóstico e manejo da irrigação na cultura do mamoeiro na região norte do Estado do Espírito Santo

• Autor(a) principal: Cordeiro, Elio de Almeida
• Data de Publicação: 2006
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/666
• topic: Mamão; Irrigação; Uniformidade; Carica papaya; Papaya; Irrigation; Carica papaya; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENGENHARIA DE AGUA E SOLO

The papaya tree (Carica papaya L.) it is a typical fruit bowl of tropical and subtropical areas and Brazil stands out as the largest world producer of papaya, with 26% of the world offer. Espirito Santo State is the second largest producing with a planted area of 11,500 there is and a production of 530,000 t, standing out as the largest exporter with 24,509 t exported in 2003. The bad distribution of rains in the area producing of Espirito Santo State turns the indispensable irrigation to the cultivation of the papaya tree. Recent work accomplished by technicians of INCAPER revealed that 87% of the properties that produce papaya irrigate based on the farmer's experience. The present work was developed in two stages; in the first stage evaluations of irrigation systems and handling were acco mplished in 29 properties and it had as objective to accomplish a diagnosis of the irrigation in the culture of the papaya tree in the North area of Espirito Santo State, in the period of September 3, 2004 to July 26, 2005, being appraised seventeen irrigation systems for microaspersão, seven for central pivot, four for leak and a micro spray. The uniformity coefficients were: coefficient of uniformity of Christiansen (CUC), coefficient of distribution uniformity (CDU) and the statistical Coefficient of uniformity (ECU). For evaluation of the irrigation, they were retired samples of soils before the irrigation, in all the appraised properties, in the layers 0-20, 20-40 and 40-60 cm of depth, for determination of the current humidity of water in the soil, it curves of retention of water in the soil and apparent density of the soil. The obtained results were: in 27% of the irrigation systems the values of found CUC went superiors at 90%, 69% of the systems presented values of reasonable considered CDU the excellent ones and the values of CUE were considered acceptable the excellent for 79% of the systems. The results of the evaluations accomplished in the irrigation systems showed that in 10% of the properties the accomplished irrigations were appropriate. In the other systems the irrigations were excessive or it was not enough to elevate the humidity of the soil to the field capacity. The analysis of the results allowed the following conclusions: the best uniformities of application of water were observed for micro aspersion systems, for the pivot systems they were, in its majority, reasonable and the worst results went to irrigation systems for dripping. In most of the cases, the irrigations were made after the appropriate moment and the sheet of applied irrigation went smaller than to necessary sheet to elevate the humidity of the soil to the field capacity. The irrigations accomplished counting with the experience of the producer don t just allow to quantify in an appropriate way the irrigation sheet to be applied. It can increase the productivity of the culture of the papaya tree with a program of irrigation handling. In the second stage, it settled an experiment in the municipal district of Linhares-ES with the objective of evaluating the development and the productivity of the culture of the papaya tree with and without irrigation handling. The experiment was set up in outline of subdivided portions, with two treatments of irrigation handling in completely randomized design, with six repetitions. In the first treatment the irrigations were accomplished following the responsible technician s recommendation for the irrigation of the farm, based on observation of the field (Trat. Field). In the second treatment, the daily handling of the irrigation values obtained by the software being used Irriga-Gesai (Trat. ETc), it was based on data of medium temperature, relative humidity, speed of the wind, precipitation and solar radiation collected in a close installed automatic meteorological station to the experiment. The appraised parameters were: plant height, stem diameter, number of leaves, number of flowers, number of fruits for plant, number of picked fruits, weigh medium of fruits and productivity of the culture for each treatment. The irrigations accomplished in the field treatment didn't assist the demand hydric of the culture, in several occasions the deficit of water in the soil surpassed the limit of 80% of the total readiness of water in the soil, committing the productivity. All the appraised parameters presented better results in Trat. ETc. The total of fruits picked in Trat. Field was of 6,099 and in Trat. ETc it was of 6,622. The medium weight of fruits picked in Trat. Field was of 357 g and in Trat. ETc of 390 g. The medium productivity for plant in Trat. Field was of 973 g and in Trat. ETc of 1,141 g and the productivity in Trat. Field was of 74.92 t ha-1 against 87,62 t ha-1 in Trat. ETc. The irrigations with base just in the field experience they don't assist the needs hydrics of the culture satisfactorily, they can provoke deficit of water in the soil and to reduce the productivity of the culture. The adapted handling of the irrigation provides better development of the plant providing better production and larger productivity.