Growth of Jatropha curcas plants submitted to water deficit and increasing nitrogen doses

Abstract

The objective of the present study was to assess the severity of water deficit in Jatropha curcas plants under different nitrogen doses. The experiment was set up in a randomized complete block design with a 5 x 2 factorial [five doses of urea with 45% nitrogen (0; 300; 600; 900; 1200 mg per pot)] and two water supply levels, irrigated and water deficit, and four replications. The Jatropha curcas seeds were sown in 5 L pots with substrate consisting of oxisol, sand and manure at the ratio 3: 1: 0.5, respectively. The nitrogen was added as organic matter in the soil may have contributed to absence of interaction between the factors water deficit and nitrogen dose because it already supplied the minimum nitrogen for the plant metabolism. The nitrogen doses studied did not interfere in the water deficit severity in Jatropha curcas plants, but the plants presented tolerance to water deficit and used delayed dehydration as tolerance strategy. Jatropha curcas plant production in substrate containing red-yellow latossol, sand and manure at the ratio 3:1:0.5, respectively, and organic matter content similar or equal to 1.9% did not require nitrogen fertilization.