Componentes produtivos do trigo afetados pela densidade de semeadura e aplicação de regulador vegetal

Abstract

ResumoMelhorar as características produtivas de plantas cultivadas através de práticas de cultivo é um dos principais desafios da pesquisa frente à crescente demanda de alimentos em nível mundial. O presente trabalho teve por objetivo estudar as características morfofisiológicas e suas relações com os componentes da produção e a produtividade da cultura trigo em função da densidade de semeadura e da aplicação de reguladores vegetais. O experimento de campo foi conduzido em delineamento experimental de blocos casualizados em esquema de parcelas sub-divididas com quatro repetições. As parcelas foram formadas por quatro densidades de semeadura (30, 50, 70 e 90 plantas m -1 ) enquanto as sub-parcelas foram formadas pela aplicação de reguladores vegetais [controle, (IBA+GA+KT), Etil-Trinexapac e (IBA+GA+KT) + Etil-Trinexapac]. Foram avaliados o acúmulo de matéria seca, a altura de plantas, a distância entre fonte e dreno, as trocas gasosas e a produtividade da cultura. A aplicação de EtilTrinexapac resultou em diminuição da altura de plantas, da distância fonte-dreno e do desenvolvimento da folha bandeira, sem afetar a produtividade da cultura. A densidade de semeadura afetou o acúmulo de matéria seca de plantas, sendo que o maior acúmulo de matéria seca na fase de antese teve efeito positivo direto nos componentes da produção e na produtividade da cultura nas menores densidades. Palavras-chave: Triticum aestivum L., perfilhamento, acúmulo de matéria seca, folha bandeira, IBA+GA+KT, Etil-Trinexapac AbstractImprovement on yield potential of plants by crop management is the main research challenge due to the growing of food demand worldwide. The objective of this work was to study physiological and morphological traits and its relationship with yield components and yield of wheat as affected by sowing densities and plant growth regulators. The experimental design was a split-plot design with four replications. The plots were consisted by four sowing densities (30, 50 70 and 90 plants m -1 ) and the subplots were consisted by plant growth regulators [control, (IBA+GA+KT), Trinexapac-Ethyl e (IBA+GA+KT) + Trinexapac-Ethyl]. Dry matter accumulation, plant height, source-sink distance, gas exchange and yield were determined. Trinexapac-Ethyl application resulted in decreasing of plant height, source-sink distance and flag leaf length; however, the grain yield was not affected. The number of plants per unit area affected dry matter accumulation. Higher dry matter accumulation showed direct relationship with yield and yield components in lower plant densities.

Influence of wheat populations arrangement on growth characteristics and grain yield

“…This result as noted by others authors (Fioreze and Rodrigues, 2014). Plant height can be affected by plant population and generally higher in larger populations as the interspecific competition caused plants etiolating.…”

Physiological and agronomic traits of cabbage plants hybrid Fuyutoyo ® sprayed with plant growth regulators

“…According to Fioreze & Rodrigues (2014), foliar sprays with plant growth regulators can promote changes in stomatal development, related to their quantity and size and can even collaborate to stomatal opening and closing, resulting in changes in gas exchange. These same authors verified in wheat, that the flag leaf transpiration rate increased significantly with foliar sprays using the mixture of plant growth regulators.…”

“…Hormone balance in plants directly reflects the productivity, defining the crop phenotypic expression depending on the resource availability in the cultivation environment (Fioreze & Rodrigues, 2014). The authors observed a possibility to improve the productive traits of plants through exogenous application of plant growth regulators (Reghin et al, 2000;Bertolin et al, 2010;Palangana et al, 2012).…”

“…P l a n t g r o w t h r e g u l a t o r s o r bioregulators are substances which produce effects similar to plant hormones when they are applied to plants. In agriculture, regulators are able to promote plant development and productivity (Reghin et al, 2000;Bertolin et al, 2010;Palangana et al, 2012), and also stimulate stake rooting (Fischer et al, 2008), promote dormancy breaking in fruits and favor budding (Segantini et al, 2011), accelerate or delay the ripening of fruits (Jadoski et al, 2011) and control plant development, helping cultural management and harvesting, among other purposes (Fioreze & Rodrigues, 2014).…”

Physiological changes and in the carbohydrate content of sunflower plants submitted to sub-doses of glyphosate and trinexapac-ethyl

“…The increased sugar cane productivity is due to, among other factors, the application of growth regulators (Fioreze and Rodrigues 2014), which are commonly applied via aerial spraying. This can lead to changes in the development of non-target plants grown in parallel.…”