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| Faria,R.T. de; Folegatti,M.V.; Frizzone,J.A.; Saad,A.M.. |
| The economical benefits of different irrigation strategies were assessed by long term simulation (20 years) for dry beans in Paraná, Brazil. The model BEANGRO was used to simulate crop yield and irrigation requirements assuming eight levels of irrigation threshold (20 to 90% of the remaining soil available water in steps of 10%), in addition to a level considering no irrigation. Net return was the objective function to select the optimum irrigation management strategy, assuming fixed and stochastic distributions of historical product price. The results showed that yield was significantly increased by irrigation despite a high variability for all the simulation strategies, due to variations on growth conditions over the years. Although the net return was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Irrigation; Modeling; Economical analysis. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161997000300018 |
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| Ferrarezi,Rhuanito Soranz; Bataglia,Ondino Cleante; Furlani,Pedro Roberto; Schammass,Eliana Aparecida. |
| For high technology seedling production systems, nutrition plays an important role, mainly the fertigation with iron chelates to prevent its deficiency. This study had the goal of searching for alternative iron sources with the same nutrient efficiency but lower cost in relation to nutrient solution total cost. An experiment was carried out in 56 cm³-conic-containers tilled with a pine bark/ vermiculite mixed substrate using Fe-DTPA, Fe-EDDHA, Fe-EDDHMA, Fe-EDTA, Fe-HEDTA, FeCl3, FeSO4, FeSO4+citric acid plus a control, and the rootstocks Swingle, Rangpur, Trifoliata and Cleopatra, in a randomized complete block design, with four replicates. Seedlings were evaluated for height, relative chlorophyll index, total and soluble iron leaf concentrations.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Seedling production; Chelates; Fertigation; Economical analysis. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162007000500010 |
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