Variability in yield and grain quality in canola genotypes with contrasting cycle length.

VILARIÑO M. P.; RONDANINI DÉBORAH P.; MIRALLES D. J.

BUZIOS

Congreso; XIV Reunion Latinoamericana de Fisiologia Vegetal y XIII Congreso Brasilero de Fisiologia Vegetal; 2011

Sociedad Brasilera de Fisiologia Vegetal

Although canola cropping has a high potential in Argentina, uncertainties in crop management and low yields are the limiting factors to expand the crop. Yield variability results mainly due to (i) lack of precise knowledge on genotype adaptation and (ii) inter-annual climatic variability. The more than 20 genotypes (winter and spring types) available have differences in vernalization and photoperiod requirements, determining changes in the duration of the phases exposing those phases to different environments as changes in temperature and incident radiation explored post flowering, affecting yield components (grain number and weight) and grain quality. The objective of this study was to analyse yield, yield components and grain quality variability in genotypes, differing in cycle length, when exposed to contrasting environments by different sowing dates. Two field experiments were carried out using 4 spring genotypes (short or intermediate cycle) and 2 winter genotypes (long cycle), sown in 4 dates (04/30 -SD1-and 07/01-SD2-, 2008;  04/15-SD1- and 06/09-SD2-, 2009) in 6-rowed plots, 3m long, 0.20 m apart with 3 replications, at the Faculty of Agronomy, Buenos Aires (34¨¬35¡¯S, 58¨¬29¡¯O) experimental field. Phenology was recorded and at maturity plants in 0.5 m-2 were harvested for yield determination. Oil and protein content and oil composition were determined. Results showed a significant genotype x year interaction (p<0.05) in grain yield. Average yields were 2390 kg.ha-1 in 2008 and 1640 kg.ha-1 in 2009; ranging from 4030 kg.ha-1 for cultivar BioAureo 2486 (short) on SD1 2008 to 422 kg.ha-1 (winter cultivar Gospel), on SD2, 2009. Winter-genotypes yielded poorly (eg. SD2, 2008) due to high temperatures during the critical period avoiding fulfil vernalization requirements.In both years, spring genotypes reached higher oil concentration than winter genotypes due to stressful temperatures (¡Ã 30¨¬ C) during the grain filling period. The delay in sowing date decreased oil concentration (4-5 points). A negative correlation between protein and oil concentration was found, but oil composition was quite stable. We conclude that it is possible to reach high yields and good oil quality with an adequate selection of the genotypes for each particular environment, placing flowering date in early spring to avoid high temperatures.