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| Author(s): |
Manuel Antonio Navarro Vasquez
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Piracicaba. , gráficos, ilustrações, tabelas. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2003-08-29 |
| Examining board members: |
Marcos Vinicius Folegatti;
Rubens Duarte Coelho;
Sergio Nascimento Duarte;
Fernando Felipe Ferreyra Hernandez
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| Advisor: | Marcos Vinicius Folegatti |
| Field of knowledge: | Agronomical Sciences - Agricultural Engineering |
| Indexed in: | Banco de Dados Bibliográficos da USP-DEDALUS; Biblioteca Digital de Teses e Dissertações - USP |
| Location: | Universidade de São Paulo. Biblioteca Central da Escola Superior de Agricultura Luiz de Queiroz; ESALQ-BC/t635.61; N322f 82049 |
| Abstract | |
The objectives of this work were: a) to determine the effect of two dripper installation depths, three irrigation depths and four potassium doses applied in surface and subsurface (SDI) irrigation on the productivity and quality of muskmelon frutis under protected conditions, b) to evaluate the water and potassium dynamics in the soil and c) to determine the muskmelon evapotranspiration (ETc) and crop coefficient (Kc) at different growth stages. The experiment was realized between September/2001 and January /2002, at ESALQ/USP Experimental Field, in Piracicaba - São Paulo State, Brazil (Latitude 22o42'30"S, Longitude 47o38'00"W). The statistical test was realized in a randomized blocks with three repetitions, arranged in factorial outline of 2x3x4. The treatments resulted from the combination among two depths of installation of the dripline, three irrigation levels and four potassium doses: Dripline depths were positioned 0,0 and 0,2 m from soil surface (P1 and P2); the irrigation levels L1, L2 and L3 were 33, 67 and 100 percent of daily evaporation from a modified pan, and the potassium doses K0, K1, K2 and K3 (0, 6, 9 and 12 g of K2O pl-1). The fertirrigation was applied every two days based on nutrient absorption curves. Tensiometers and solution extractors, were used to monitor soil moisture and to evaluate the potassium concentration in the soil. The total evaporation from the modified pan during the crop cycle was of 417,32 mm. For the values of matric potential, the irrigation level L2 in the position P2 and L3 at both driplines depths (P1 and P2), maintained the best water conditions. The potassium doses, the irrigation levels and the driplines depths influenced the concentration and the spatial and time distribution of the K+ ion. The application of the potassium doses K1 and K2 (6 g of K2O pl-1 and 9 g of K2O pl-1) in combination with the irrigation levels L3 (417,32 mm) and dripline position P2 (0,2 m) resulted the best total productivity (65.108,33 kg ha-1 and 69.646,00 kg ha-1) and marketable productivity (61.427,60 kg ha-1 and 66.224,31 kg ha-1). The Kc and ETc of the melon crop under greenhause conditions can be well estimated considering plant leaf area along the vegetative cycle. (AU) | |