Evaluación agronómica de seis variedades de arroz (Oryza sativa L.) sembradas en dos épocas bajo riego, en el municipio de San Buenaventura, Bolivia

Rice constitutes the food base of large developed and developing regions; increasing its production is an essential element in the fight against hunger and malnutrition. In this sense, the objective of the research is to carry out the agronomic evaluation of six rice varieties planted in two seasons, under irrigation, in the municipality of San Buenaventura. The research was carried out in the Santa Rosita community, San Buenaventura canton, department of La Paz, Bolivia. The factors used were rice varieties (SAAVEDRA 27, MAC-18, CAISY 50, IAC-103, EPAGRI-109 and PAITITÍ) and sowing seasons (dry and wet), resulting in 12 treatments; the response variables were days to flowering, days to harvest, number of tillers per plant, plant height, panicle length, number of panicles, number of grains per panicle, percentage of mature grains, weight of 1000 grams and yield. The varieties CAISY 50 and EPAGRI-109 showed the same behavior and a higher number of days to flowering and days to harvest than the other varieties, which shows that they have a longer biomass formation time. Yields in dry season (5 054.52 kg ha-1) and wet season (3 340.50 kg ha-1) differed considerably, the yields obtained in dry season were statistically similar, affirming that any variety is recommended in dry season; in wet season there were differences, with the CAISY 50 variety having the highest recommended yield (3 340.50 kg ha-1). The new high-yielding varieties and the use of improved rice cultivation practices have shown that in areas with sufficient water availability, it is possible to obtain high yields, giving farmers the possibility to be competitive and efficient.