Morfofisiologia e produção da mamoneira cultivada com águas salinas e doses de nitrogênio.

Abstract

The castor bean is an oil of relevant economic and social importance, whose products and by-products are used in castor chemical industry and agriculture. In this sense, objetivou- to evaluate the growth and production of castor bean components cv. BRS Energy, irrigated with water of different salinities and fertilized with different nitrogen rates, which was grown in lysimeters under field conditions. We studied the effect of ave leveis of electrical conductivity of irrigation water - CEa (0.31 1.21 2.11 3.0 and 3.9 dS m-l) associated with four doses of fertilizer nitrogenada- DN (701 1001 130 and 160% of the recommended dose for N tests vasos- 100 mg kg-l). We used the experimental design of randomized blocks in a factorial arrangement 5x4. with three replications. resulting in 20 treatments, and experimental units distributed in single row spaced 0.9 m between rows and 0.7 m between plants within the row . The irrigation with saline waters reduces the growth and production of castor bean, observed by reduced plant height, stem diameter, leaf área, Seed mass of primary raceme the most affected variable. The absolute and relative growth rate of plants increased respectively with saline water leveis from 1.9 to 3.9 dS m-l in the range of 30 to 40 days after sowing. Increasing nitrogen leveis up to 160% of the recommended dose provides increased leaf área of castor bean BRS Energy. The saline irrigation water increased prolongs the period for issuing the primary raceme of castor, being increased in ten days when using CEa of water equal to 3.9 dS m-1.