Basal and supplementary nitrogen applications on bread wheats (Triticum aestivum L.). II. Effect on grain quality

Mario Mellado Z.1 y Denise Granger Z.2

Six field trials under irrigated conditions were carried out during 1991, 1992 and 1993 at Quilamapu Regional Research Center of the "Instituto de Investigaciones Agropecuarias" (INIA), Chillán, (360 31' S, 71 0 55' W, and 217 m.a.s.I.), in order to evaluate the effect of basal and supplementary nitrogen application on the grain quality of two wheat varieties with different growing behavior. An split plot desing with four replications was used, with two treatments and four subtreatments. Treatments: basal nitrogen aplication of 150 kg/ha. T1= all nitrogen at sowing. T2= half nitrogen at sowing and half at end of tillering stage: Subtreatments: suplementary application rates of 50 kg/ha N in four development stages. t1 = during jointing. t2 = during heading. t3 = during flowering. t4 = during milk grain. The results showed that the most effective way to increase grain quality in winter and spring wheats was to apply a supplementary nitrogen rate between heading and flowering. This tendency was c1earer in winter than in spring wheat.

Keywords: bread wheat, Tríticum aestívum L., nitrogen split application, grain quality.
1 Centro Regional de Investigación Quilamapu (INIA), Casilla 426, Chillán, Chile.
2 Centro Regional de Investigación La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.