ABSTRACT
Producing high-quality seeds for agroecological agriculture is needed because the plants will be exposed to a diversity of environments and management practices. Sowing times and population densities can influence the quality of seeds produced by landraces. Further, seeds for agroecological cultivation must not be contaminated by transgenes. In this context, it is necessary to know the agronomic performance of landraces outside of the recommended growing period to avoid gene flow with transgenic cultivars. Thus, the objective of this work was to determine the germination rate, vigor and sanitary quality of seeds of maize genotypes cultivated in an agroecological system at different sowing times and densities. A split-split-plot design was used in the 2016/2017 and 2017/2018 growing seasons. The physiological quality evaluation was based on germination and vigor tests, and the sanitary quality was obtained by visually examining the seeds. The results showed a significant simple effect of genotype, sowing time and density, as well as double and triple interactions among factors for all evaluated traits. The most suitable time for sowing the corn landraces evaluated in an agroecological system in western Santa Catarina is September, when the seeds exhibited the highest percentage of germination and vigor and there was a lower incidence of pathogens. At this time, a density of 55,000 plants·ha–1 had the best result for germination. Late sowing was tested to avoid gene flow from transgenic varieties that usually are sown in September, but the results indicated penalties, such as a decrease in seed yield and quality.
Key words
Zea mays ssp. mays L.; germination; vigor; temporal isolation; genetically modified organism
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Note. Monthly average of precipitation (mm·m–2; up), radiation (W·m–2; median) and average temperature (°C; bottom) from 2008 from the automated weather station (27°05’24”S; 52°38’05”W), located at Chapecó, SC, Brazil, 5 km from the experimental unit.
Note. Monthly average of precipitation (mm·m–2; columns), radiation (W·m–2; black lines) and temperatures (°C); blue, red and dashed black) from 2008 thru 2018, September 1, 2016 through June 30, 2017 and September 1, 2017 through May 31, 2018. The historical weather data were obtained from the Foz do Chapecó Energia S.A. and specifically the average minimum temperatures and average maximum temperatures from September 1, 2016 through May 31, 2018, were obtained from the automated weather station (27°05’24”S; 52°38’05”W), located at Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Chapecó, SC, Brazil (
Note. Means followed by the same lowercase letters, for each sowing time, and uppercase letters, for each genotype, do not differ by Tukey’s test (p < 0.05).
Note. Means followed by the same lowercase letters, for each sowing time, and uppercase letters, for each genotype, do not differ by Tukey’s test (p < 0.05).
Note. Means followed by the same lowercase letters, for each sowing time, and uppercase letters, for each genotype, do not differ by Tukey’s test (p < 0.05).