Cultivares de arroz de terras altas afetadas pelo manejo do solo

Abstract

A identificação de cultivares melhores adaptadas a cada tipo de manejo do solo, poderá favorecer o aumento da produtividade da cultura do arroz de terras altas. O objetivo do trabalho foi estudar o desempenho de genótipos de arroz de terras altas em dois sistemas de manejo do solo, preparo convencional com arado de aiveca (PC) e sistema plantio direto (SPD) nas condições do Cerrado. O estudo foi conduzido em dois locais no município de Ipameri, GO, ano 2008/2009. O delineamento experimental foi em blocos ao acaso, no esquema fatorial 2 x 5, com cinco repetições. O primeiro fator foi o sistema de manejo do solo (PC e SPD) e o segundo era constituído das cultivares (BRS Sertaneja, BRS Primavera, BRS MG Curinga, Caiapó e BRS Bonança). As cultivares de arroz BRS Sertaneja, BRS MG Curinga, Caiapó e BRS Bonança tiveram maiores produtividades no PC que no SPD. A cultivar BRS Primavera teve produtividade semelhante nos dois sistemas de manejo do solo. A cultivar BRS Primavera foi a mais produtiva no SPD, e no PC as cultivares tiveram desenvolvimento semelhante. A produtividade de grãos do arroz foi maior na UEG-Ipameri que na Fazenda Santa Brígida. Palavras-chave: arado de aiveca, Oryza sativa, produtividade, sistema plantio direto Cultivars of upland rice as affected by soil management

Genotype selection and addition of fertilizer increases grain yield in upland rice in Suriname

“…Plant height (PH) was measured as the distance between the soil surface and the height of the tallest panicle on plants at the time when the crop was at the phenological stage of milky grains. The grain yield of rice is determined by three components: (i) the number of panicles per unit area, (ii) the number of grains per panicle, and (iii) the mass per 1 000 grains (Yoshida 1981;Nascente et al 2013). So, the number of panicles per unit area (PAN) was determined by counting their number within a 1 m length of one of the rows, randomly selected in the usable area of each plot.…”

“…Number of grains per panicle (GRAIN), was determined by counting the number of grains in 10 panicles randomly sampled in the usable area and divided by 10. The mass of 1 000 grains (MGRAIN) was determined by weighing grains from a random collection with a correction to 13% of water content (Yoshida 1981;Nascente et al 2013). Total grain yield (YIELD) for each plot was determined by weighing all the harvested grain from each plot, corrected to 13% water content.…”

“…However, to recommend the use of the most appropriate cultivars for each region, seeds from different sources need to be evaluated by growing them in locations with a range of climate conditions and at different times throughout the year. The behavior of cultivars can vary in relation to the environment in which they are grown (Nascente et al 2013). However, in Suriname there has been virtually no work on breeding for improved cultivars of upland rice.…”

Seed treatment, soil compaction and nitrogen management affect upland rice

“…NTS facilitates crop rotation with soybean and corn (Nascente et al 2011), but upland rice does not show good development or yield under this system (Olofintoye & Mabbayad 1980, Kluthcouski et al 2000, Nascente et al 2011, Nascente et al 2013b. Therefore, it is important to develop technologies to improve rice grain yield under NTS, aimed at sustainable agriculture, higher food production and water conservation (Farooq et al 2009).…”

“…According to Moura Neto et al (2002), Guimarães et al (2006), Nascente et al (2011) and Nascente et al (2013b), producers should observe which genotypes produce more in each soil management, when they grow rice, in order to maximize yield.…”