Fertilization with Nitrogen, Phosphorus and Potassium in Upland Rice Cultivars in the Southern Region of Rondônia, Brazil

The upland rice productivity in the state of Rond?nia is still low, in view of the potential of culture. The use of cultivars adapted to different regions and more responsive to fertilizer employed is an essential practice which can change that. The aim of this study was to evaluate the agronomic characteristics and productivity of two upland rice cultivars with nitrogen, phosphorus and potassium (N-P-K) doses in two municipalities in the southern state of Rondonia region. The experimental design was a randomized block design with four replications in a factorial 2 × 2 × 5, with the first factor composed of two cultivars (hybrid Ecco and conventional farming AN Cambará), the second factor, the environment of the two municipalities, Cerejeiras and Vilhena and the third factor of five doses of N-P-K (0-0-0, 30-40-30, 60-60-60, 90-90-90 and 120-100-120 kg·ha-1). The characteristics evaluated were: tillering, number of integers and sterile grains per panicle, weight of 1000 grains, grain yield (kg·ha-1) and whole grain yield. There was no triple interaction between the three factors for any of the traits. The hybrid Ecco has higher tillering ability than AN Cambara and presents fewer sterile grains per panicle, heavier 1000 grains and hence greater productivity. For both cultivars, the highest yields are obtained with a dose of 120-100-120 kg·ha-1 N-P-K. For the Ecco, the productivity is achieved with this dose and the dose of 90-90-90 kg·ha-1 is statistically similar. There is no difference in productivity between the municipalities when the dose of N-P-K is less than 60-60-60 kg·ha-1. The highest yield of whole grains in function of N-P-K fertilization is obtained in Cerejeiras.

Agronomic Performance of Cultivars of Upland Rice in the Southern of the Region of Rondonia,Brazil

The upland rice is grown in most Brazilian states. However, in many of them the yield obtained is low. The choice of cultivar more suited to a particular environment can contribute to increased productivity of this crop. This research aimed to evaluate the performance of a hybrid cultivar of upland rice (Ecco) and five conventional cultivars (BRS Monarca, BRS Primavera, AN Cambará, BRS Sertaneja and BRS MG Curinga) in two environments (Vilhena and Cerejeiras). The tests were conducted in the agricultural year 2010/2011. We evaluated the following characteristics: tillering, panicle number per unit area, number of filled grains per panicle sterile, mass of grains per panicle, 1000 grain weight, grain yield (kg·ha-1) and whole grain yield. There was no cultivar x environment interaction for all traits. Greater tillering, higher panicle number per area, higher productivity and yield of whole grains in the municipality of Cerejeiras were observed, while the highest number of sterile grains per panicle was obtained in Vilhena. The hybrid Ecco highlighted in relation to all other cultivars is in relation to tillering, panicle number per area and grain yield. The municipality of Cerejeiras is the most suitable for the cultivation of upland rice.