Row spacing and sowing density as management strategies to improve radiation capture, radiation use efficiency and grain yield in chia (Salvia hispanica L.)

ANUCH TIRANTI J.V.; CURTI, RAMIRO N.; ACRECHE M.M.

Congreso; XXXIII Argentinian Meeting of Plant Physiology RAFV 2021; 2021

Sowing density (SD) and row spacing (RS) are management strategies that modify crop canopy, radiation capture, radiation use efficiency (RUE) and grain yield. The objective was to determine the combined effects of SD and RS on radiation interception, RUE and grain yield generation in chia. Two experiments were conducted during 2017 and 2018 using a factorial design. In both years, the RS were 0.26 and 0.52 m, whereas the SD were 5, 9, 13 plants m-2 in 2017 and 9, 13, 17 y 21 plants m-2 in 2018. RS or the interaction between SD and RS did not affect grain yield and yield components. At higher SD, increases in grain yield were associated with increases in total dry matter without modification in harvest index. Grain number m-2, grains per verticillaster and verticillaster m-2 also increased with SD. In the SD5 treatment, the increase of 1000-grain weight partially offseted the low grain number m-2. The intercepted photosynthetically active radiation (PAR), adjusted by a logistic model, revealed that SD5 was the only treatment which did not reached maximum PAR interception (78%) leading to the lowest accumulated intercepted PAR and RUE. The treatment RS26 needed less thermal time to reach maximum interception and had higher accumulated intercepted PAR than RS52 according to the logistic model. Summarysing, the increase in SD generated increases in accumulated PAR and RUE that lead to higher growth and grain yield.