Produtividade de arroz de terras altas em função de reguladores de crescimento

Abstract

Upland rice yield as a function of growth regulatorsThe use of sprinkler-irrigation and/or high levels of fertilization in upland rice can increase plant height and hence plant lodging. Lodging can be controlled by using growth regulators, in order to reduce plant height. The objective of this study was to evaluate the efficiency of plant growth regulators applied at the stage of panicle primordium differentiation on the reduction of plant height and the impact on grain yield and its components of upland rice cultivar Primavera, under sprinkler irrigation. The experiment was arranged in a 3x4 factorial randomized blocks design with four replications. Treatments consisted of: mepiquat chloride and trinexapac-ethil applied at doses 9, 50, 100, and 200 mg a.i. ha-1, and paclobutrazol at doses of 0, 25, 50, and 100 mg a.i. ha-1. Plant growth regulators reduced rice plant height; increasing doses of regulators reduced upland rice grain yield and its components; trinexapac-ethyl was the most harmful to rice grain yield.In this study, it was not identified the dose of growth regulator that allied reduction in plant height and did not cause decrease in rice yield.

Growth regulator and maize response to the increase in plant density

“…This behavior complies with the present work hypothesis, which states that the growth regulator effect on maize plant height is more pronounced in late sowing dates. The reduction of maize plant height with the use of Trinexapac-ethyl was also reported by Fagherazzi (2015), Pricinotto et al (2015) and Durli (2016) and in other species of the Poaceae family, such as wheat (Grijalva-Contreras et al, 2012;Marco Junior et al, 2013;Chavarria et al, 2015), rice (Arf et al, 2012;Alvarez et al, 2014) and white oat (Kaspary et al, 2015).…”

Growth, yield and agronomic efficiency of rice (Oryza sativa L.) cv. IAPAR 117 affected by nitrogen rates and sources

“…Therefore, the yield of upland rice is low, contributing with only 41% of Brazilian production, despite having more than 60% of rice cultivation areas in Brazil (Alvarez, Crusciol & Nascente, 2014).…”

Oat yield through panicle components and growth regulator

“…Lodging is directly related to the size of the plant and stem resistance, an event that can limit oat harvest and grain yield (Hawerroth et al, 2015). The use of growth regulators in the reduction of lodging has been a practice already employed in crotalaria (Kappes et al, 2011), rice (Alvarez et al, 2014) and wheat (Chavarria et al, 2015). Dalchiavon et al (2012), using multiple linear regression model, estimated rice grain yield incorporating to the model the number of panicles m -2 , number of spikelets panicle -1 and the weight of one thousand grains.…”