Grain yield of dual-purpose wheat cultivars as affected by nitrogen and cuttings

Abstract

The aim of this work was to evaluate the effect of nitrogen fertilization and aerial part cuts on yield components, grain yield and quality of the grains for dual-purpose wheat cultivars. The experiment was carried out between May and November 2007 and the experimental design was randomized complete blocks with three replications. The main causes of variation were dual-purpose wheat cultivars (BRS Figueira, BRS Umbu, BRS Guatambu and BRS Tarumã), nitrogen doses (0, 45, 90, 135 and 180 kg ha -1 ) and cut systems. Each plot was subdivided by cut management (without cut, one cut and two cuts). Spike mass, number of spikelets per spike, number of grains per spikelet, grain yield and hectoliter weight were evaluated. Nitrogen fertilization did not affect the performance of wheat genotypes, but there was interaction between the management systems and the cultivars. The shorter-cycle cultivars (Figueira and Umbu) presented greater grain yield than the others when they were not cut. As quality and yield fell when Figueira and Umbu were cut, the later cultivars (Tarumã and Guatambu) are more adapted to cut (grazing). The lack of an effect from nitrogen dose and application strategy on the variables studied was influenced by the ecological conditions prevailing during the experimental period.Key words: Triticum aestivum, winter cereal, crop-livestock integration.Trigo duplo propósito submetido a regimes de corte: produção de grãos ) e os regimes de corte. As parcelas foram subdivididas conforme os manejos (sem corte, um corte e dois cortes). As variáveis avaliadas foram: massa da espiga, número de espiguetas por espiga, número de grãos por espigueta, rendimento de grãos e peso do hectolitro. A adubação nitrogenada não alterou o desempenho dos genótipos de trigo, porém houve interação entre os manejos e as cultivares. As cultivares de ciclo mais curto (Figueira e Umbu) porporcionam maior rendimento de grãos que as demais quando não submetidas ao corte, porém têm sua qualidade e o rendimento reduzidos quando foram cortadas, demonstrando que as cultivares tardias (Tarumã e Guatambu) são mais adaptadas ao corte (pastejo). A falta de efeito da dose e do manejo de aplicação do nitrogênio nas variáveis avaliadas foi influenciada pelas condições edafoclimáticas reinantes durante o desenvolvimento da pesquisa.

Urease inhibitor (NBPT) and efficiency of single or split application of urea in wheat crop

“…Several studies have been conducted to evaluate the correct time of nitrogen fertilization on wheat crop under Brazilian tropical conditions (Silva et al, 2008;Megda et al, 2009;Espindula et al, 2010;Hastenpflug et al, 2011;Teixeira Filho et al, 2011Espindula et al, 2013. These studies take into account the application of nitrogen fertilizer at sowing and topdressing and suggest that N application just at sowing is enough to provide N during crop cycle.…”

Productivity and the presence of mycotoxins in oats, wheat, and triticale subjected to grazing

“…In Paraná, there are three different regions that produce wheat, and BRS Tarumã wheat is recommended only for region 1 (South-Central region and southeast Paraná, represented by Ponta Grossa, Guarapuava, and Palmas), while western Paraná, in the Marechal Cândido Rondon region, belongs to region 3, suitable for producing wheat adapted warm weather, moderately dry climate, and low altitude (MONTECELLI et al, 2014). Hastenpflug et al (2011) reported BRS Tarumã wheat productivities of 1362.15 kg ha -1 , 1175.25 kg ha -1 , and 891.44 kg ha -1 without cuts, with one cut, and with two cuts, respectively, in Pato Branco (PR, Brazil). These results were superior to the productivity in this experiment.…”

“…It is also important that there is no excessive trampling so that the soil porosity is not compromised, as this consequently impairs water infiltration and soil aeration, which contribute to the development of the summer crops' deep roots. In addition, the end of the grazing period must be before the elongation of the internodes of the plants, and must be timed so that the residual height of the crops assures a minimum of 2 t ha -1 of haystack on the stubble (BARTMEYER et al, 2011;CRUZ et al, 2010;HASTENPFLUG et al, 2011).…”

“…During leaf growth, there is a mobilization of carbohydrates and a progressive increase in the absorption of nitrogen, which reaches its peak during the reproductive stage and decreases during the grain-filling phase (HASTENPFLUG et al, 2011).…”

“…These production components are directly related to the yield and quality of the winter crop grains (HASTENPFLUG et al, 2011). Grazing must be continued, regardless of the system put into place, whether rotated or continuous, until the plants reach the recommended height for the species, so that there is high performance and high forage quality.…”