Resumen

ORTIZ DOMINGUEZ, Aída  y  GARCIA, Oscar. Efecto del ácido Giberélico sobre el rendimiento de la variedad de arroz Araure 4. Agronomía Trop. [online]. 2002, vol.52, n.4, pp.485-495. ISSN 0002-192X.

SUMMARY     With the objective of evaluating the effect of Activol growth regulator (gibberellic acid) in rice, a study was performed in a rice lot of Araure 4 variety of Portuguesa State, Venezuela. The experimental desing used was a random block with 4 replicates and 6 treatments according to the amount of active ingredient used (T1= 0 g ha^-1; T2= 2 g ha^-1; T3= 3 g ha^-1; T4= 4 g ha^-1; T5 = 5 g ha^-1; T6= 6 g ha^-1). The product was sprayed to 30 m² per treament and only 15 m² were harvested. Applications were done when the crop had 15 a 20% of panicles emerged using a Gloria type hand sprinkler with constant flow (100 l ha^-1). Variables evaluated were: yield (kg ha^-1), number of panicles per m2, number of grains per panicle, sterility percentage, weight of 1000 grains; panicle length, panicle exertion, grain specific weight and percentages, of whole grains, white belly grains and chalky grains. Analysis of variance was applied to data and variables that showed statistical differences were subjected to Duncan´s Multiple Range Test at 5%. Results showed that treatments with gibberellic acid produced higher yields than control (without Activol), and increased weight of 1000 grains, exertion and length of panicle. Treatment T5 (= 5 g ha^-1), showed highest yield in summer and rainy season with values of 6.505,2 kg ha^-1 y 6.350 kg ha^-1, respectively. T1 (without Activol) had the lowest yield in both seasons, with an average of 6.505,2 kg ha^-1 y 6.350 kg ha^-1, respectively. Milling quality was not affected by the application of gibberellic acid.

Palabras clave : Rice; Oryza sativa L; growth regulador.