Response of some rice cultivars to different rates and split applications of nitrogen

• Main Authors: Leilah, A.A, El Kalla, S.E. (Mansoura Univ., Mansoura (Egypt). Agronomy Dept.)
• Format: Conference Proceeding
• Language: English
• Published: Los Banos, Laguna (Philippines) IRRI 1989
• Subjects: ABONOS NITROGENADOS; ENGRAIS AZOTE; METHODE D'APPLICATION; METODOS DE APLICACION; ORYZA SATIVA; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; VARIEDADES; VARIETE

Two field experiments at Mansoura Experimental Station [Egypt] during the 1985 and 1986 seasons studied the effect of rates and split applications of N fertilizer on the performance of four rice cultivars. The main findings may be summarized as: a) Rice cultivars differed in their response to N. The grain yield increased with increase in the rate of applied N, up to 60 kg N/feddan in the tall variety Giza 171, and 75 kg N/feddan in the dwarf varieties IR28, IR50, and IR9752. b) IR28 was the highest yielder, closely followed by IR50; Giza 171 was the lowest yielder. c) Split applications of N fertilizer in two or three equal portions (1/2 on dry soil before transplanting and 1/2 at tillering stage or 1/3 on dry soil before transplanting, 1/3 at tillering, and 1/3 at panicle initiation stages) slightly increased grain yield, especially in Giza 171, compared with a single dose on dry soil before transplanting. d) The highest grain yield of 10.5 t/ha was obtained from IR28 fertilized with 135 kg/ha added in 2 equal portions: 1/2 before transplanting on dry soil and 1/2 at tillering stage. The lowest grain yield of 5.4 t/ha was obtained from Giza 171 fertilized with 72 kg N/ha, added in a single dose before transplanting on dry soil.