English

Fábio Luíz Checchio Mingotte,Leandro Borges Lemos,Marcela Midori Yada,Maryna Helena Garcia Gonçalves,Domingos Fornasieri Filho

doi:10.14393/bj-v31n1a2015-26074

Abstract

This study aimed to evaluate the agronomic efficiency and grain quality of rice cultivars to nitrogen application in upland conditions with supplemental sprinkler irrigation. The experiment was carried out in 2012/13 at Jaboticabal-SP on a randomized block and split plots design with four replications. The plots were composed of twelve rice cultivars (BRS Aroma, BRS Monarca, BRS Primavera, BRS Sertaneja, BRSMG Curinga, Caiapo, CIRAD 141, Guarani, IAC 165, IAC 201, IAC 202, and IAC 25), and two levels of nitrogen application (0 and 100 kg N ha -1 ) in topdress at the R 1 stage (panicle differentiation) as subplots. The N application intensifies the degree of lodging, mainly at Caiapo, Guarani, IAC 165, IAC 201 and IAC 25 cultivars. The N application affects the number of sterile spikelets per panicle, mainly in CIRAD 141, BRS Sertaneja, IAC 202, and BRS Aroma cultivars. Caiapo cultivar shows higher grain yield and agronomic efficiency in function of N application, followed by BRS Monarca, BRSMG Curinga, IAC 165, and IAC 202. Although Caiapo, CIRAD 141, Guarani, IAC 165, IAC 202, and IAC 25 cultivars present better results, all the others cultivars also present acceptable values of milling yield, without N application effects. The grain protein content in rice is increased by the N topdressing application.

Highlights

In Latin America, Brazil stands out as the only region with potential to increase rice production and meet the future demand, corresponding to 1.53% of area and 1.69% of world production, and is the largest producer among the South American countries, accounting for 55% of the production (USDA, 2013)
Once the production per unit area of lowland rice (5,779 kg ha-1) is higher than that produced in upland conditions (1,472 kg ha-1), the irrigated system contributed to 77.4% of the total production in the country (11,600.3 tons) (CONAB, 2013)
This study aimed to evaluate the agronomic efficiency and grain quality of commercial rice cultivars as a function of nitrogen topdressing application in upland conditions with supplemental sprinkler irrigation

Summary

Introduction

In Latin America, Brazil stands out as the only region with potential to increase rice production and meet the future demand, corresponding to 1.53% of area and 1.69% of world production, and is the largest producer among the South American countries, accounting for 55% of the production (USDA, 2013). Due to the fact that there is no availability to create new agricultural lands for lowland rice production, the upland rice is the alternative to meet the needs of Brazilian consumers and generate exportable surpluses, for its potential growth exceeding 50 million hectares for expansion, especially in climatically favored regions with supplemental sprinkler irrigation. This system requires cultivars with some basic features such as: low/intermediate height, narrow, short and straight leaves, short cycle, lodging resistance, high yield potential, fine-long grain, good milling yield, and good cooking behavior (FORNASIERI FILHO; FORNASIERI, 2006), as well as adaptation of cultural practices that make the system more efficient. Nitrogen (N), considered as the main factor limiting the productivity of rice under conditions of adequate water availability, deserves special attention (FAGERIA; BARBOSA FILHO, 2001; DAWSON et al, 2008)

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Conclusion