Agricultural yield components of dual purpose wheat cv. BRS Tarum under cutting and nitrogen fertilization handlings

Abstract

This experiment aimed to study the effects on grain and forage productivity in dual-purpose wheat cv. BRS Tarumã under cutting handlings and nitrogen fertilization. The experiment was conducted in area of Rhodic Hapludox in the city of Marechal Cândido Rondon, Paraná State, in a randomized block design with 12 treatments and four replications. The treatments consisted of surface nitrogen levels (0, 60, 120 and 180 kg ha -1 ) and number of cuttings accomplished (0, 1 and 2). The topdressing was split in two applications for handling of just a cutting (27 and 65 days after sowing -DAS), and three applications for handling with two cuttings (27, 65 and 96 days after sowing -DAS). Data were subjected to analysis of variance (p≤0.05). The use of one or two cuttings and the comparison between the first and second cuttings were done by F test (5%) whereas nitrogen doses were studied by regression analysis. For all variables, there was significant interaction of nitrogen doses in surface and the number of cuttings. Grain yield and its yield components were responsive to levels of nitrogen fertilization in surface as well as forage production and its quality, but the same factors were reduced with the use of cuttings. This handling increased the dry matter content and crude protein in grains.

Agronomic traits of dual-purpose wheat with different plant architectures under defoliation strategies

“…Conditions related to apical meristems removal by cutting or grazing, remaining leaf area proportion and the consequent reduction radiation interception and photoassimilates distribution, cuts or grazing beyond GS 30, delayed the maturation and shortened the grain filling period, resulting in grain yield decrease (BELL et al, 2015;HARRISON et al, 2011;HARRISON et al, 2014;SEYMOUR et al, 2015). Similar to this study, Hastenpflug et al (2011b), Carletto et al (2015), and Ramella et al (2015) made two cuts in wheat and observed that the grain yield was reduced due to cuts. Tian et al (2012) found that wheat defoliated after GS 30 resulted in reduction of more than 60% in grain yield, mainly due to meristems removal, subsequent tillers death and reduction of plant capacity to translocate resources for grain production and filling.…”

“…Similar behavior was obtained in other studies such as Tonetto et al (2011) who observed that in ryegrass, the increase in cuts number resulted in increased dry matter production. Ramella et al (2015) found that in dual-purpose wheat BRS cultivar Tarumã, FP was higher in two cuts compared to single cut. Hastenpflug et al (2011a) working with four dual-purpose wheat cultivars, managed in two cuts, obtained that in second cut, the FP practically doubled.…”

“…For these components, Hastenpflug et al (2011b) found that NSS decreased with cuts. Under two cuts management Ramella et al (2015) too found that NSS and NGS decreased. Virgona et al (2006) reported a decrease of 50-60% in NGS due to prolonged grazing periods and Tian et al (2012) reported that cuts after GS 30 resulted in 55% NGS reduction compared to non-defoliated plants.…”