The effect of drying temperatures and storage of seeds on the growth of soybean seedlings

Abstract

-Drying of seeds reduces their moisture content to levels appropriate for storage. However, care in the temperatures applied in the process is necessary to avoid damage to the seeds that are dried. The aim of this study was to evaluate the effect of different drying temperatures and storage on the growth of soybean seedlings. Harvested with a moisture content of approximately 23% (w.b.), the seeds were dried at different temperatures (40, 50, 60, 70, and 80 °C) until reaching moisture content of 12.5 ± 0.7% (w.b.), and they were subsequently stored for 180 days in an environment without climate control. A germination test and evaluations of seedling performance were carried out every 45 days, determining the full length of the seedling and hypocotyl and root lengths, along with their respective dry matter weights. The results showed that: a) the increase in the temperature of drying air affects the physiological quality of soybean seeds, and this effect is accentuated over time, especially on root length; and b) the air temperature of 40 °C can be recommended for drying of soybean seeds in association with the storage time of 180 days under storage conditions without climate control.Index terms: Glycine max L., germination, seed vigor, post-harvest.Temperaturas de secagem e armazenamento de sementes no crescimento de plântulas de soja RESUMO -A secagem de sementes permite reduzir o teor de água a níveis adequados para o armazenamento. Porém, cuidados com as temperaturas aplicadas no processo são necessários para evitar danos às sementes submetidas à secagem. O trabalho foi realizado com o objetivo de avaliar o efeito de diferentes temperaturas de secagem e do armazenamento sobre o crescimento de plântulas de soja. As sementes foram colhidas com aproximadamente 23% de teor de água, e submetidas a diferentes temperaturas de secagem (40, 50, 60, 70 e 80 °C) até atingirem 12,5 ± 0,7% (b.u.), sendo posteriormente armazenadas, em ambiente não controlado, durante 180 dias. A cada 45 dias foi realizado o teste de germinação e as avaliações referentes ao desempenho de plântulas, determinando-se os comprimentos total, do hipocótilo e da raiz, e ainda verificando suas respectivas massas de matéria seca. Com base nos resultados pôde-se concluir que: a) o aumento da temperatura do ar de secagem afeta a qualidade fisiológica das sementes, sendo esse efeito potencializado com o tempo de armazenamento, principalmente sobre o comprimento da raiz; b) a temperatura do ar de 40 °C pode ser recomendada para a secagem de sementes de soja, sendo associada ao período de armazenamento de 180 dias em condições não controladas.Termos para indexação: Glycine max L., germinação, vigor de sementes, pós-colheita.

Late seed maturation improves the preservation of seedling emergence during storage in soybean

“…In parallel to the occurrence of abnormal seedlings, the overall elongation capacity was also affected by storage ( Figures 2D and 2E). There was a decline in both root and hypocotyl length as shown previously by Hartmann Filho et al (2016) and Yagushi et al (2014) on mature soybean seeds. However, the decline was much less important for mature seeds compared to immature seeds both for hypocotyls and roots.…”

“…The loss of normal seedlings occurred faster for seeds from 7.1.3 than later stages. Given the large variation among replicates within stages, the loss of normal seedlings during storage appeared to be similar from stage 7.2 and onwards ( Figure 2C) . Hartmann Filho et al (2016) also noticed a decrease in the percentage of normal seedlings during storage and drying at temperature ≥ 40 °C when the seed moisture content decreased from 13 to 10%.…”

“…Organ elongation during emergence is controlled by external factors such as light, temperature, oxygen and soil structure that are perceived by a complex signaling network involving auxin, ethylene, gibberellins and brassinosteroids (Sánchez-Bravo et al, 2008;Lilley et al, 2012;Zhong et al, 2014;Žádníková et al, 2015;Procko et al, 2016;De Wit et al, 2016). Seedling emergence is dependent on sowing practices such as depth (Finch-Savage and Bassel, 2016;Marcos-Filho, 2016) but can also be affected by heat stress during seed development (Dornbos and Mullen, 1991) and drying rate after harvest (Hartmann Filho et al, 2016). However, how maturation stage impacts organ elongation and seedling performance after seed storage remains poorly studied.…”

Soybean Seed Vigor: Uniformity and Growth as Key Factors to Improve Yield

“…It was expected that with increasing EDAS values, the root dry mass would decrease more significantly than the shoot dry mass. In soybean plants, the embryonic axis is highly susceptible to deterioration because the radicle of the embryonic axis is in close contact with the end of the funicle and ensures the interaction with the environment, resulting in enhanced lipid peroxidation [26,27].…”

Mutagenic effects of gamma rays on soybean (Glycine max L.) germination and seedlings

“…Seedling performance was evaluated through determination of seedling height and root length [29]. Seedling height was measured point of connection of the hypocotyl with the root, up to its point of connection of the apical bud to the stem.…”