Seeds harvested on the ears have high moisture content. On that account, this study aimed at evaluating the loss of physiological quality of corn seeds harvested on the ears, as a function of different drying-delay times. Hybrid corn ears were harvested at 31% moisture and then had their drying postponed for 0, 12, 24 and 36 h, while subjected to temperatures of 30, 40, 50 and 60 °C. The physiological quality was evaluated after 0, 4, 8 and 12 months of storage. A completely randomized design was employed, in a 4 x 4 x 4 factorial scheme, with four replications. In addition, a study was performed in a seed-processing unit, reporting the average waiting time before drying and the temperatures of all loads of a corn hybrid received at the facility. The physiological quality was not affected by temperatures below 40 °C, considering 36 h of waiting before drying. At 50 ºC during the drying delay, the germination was impaired 36 h afterward, and the vigor was compromised after 24 h, with the damage effects intensifying as the storage advanced. At the temperature of 60 ºC, the deficits in germination and vigor occurred within the first hours of drying delay.

Este tutorial esta disponível em vídeo https://www.youtube.com/watch?v=hgAOoBdjsCo&t=1s.

This study aimed to evaluate the effect of genetic composition and arrangement between female and male parents on tolerance to delayed drying of maize seeds, evaluating the physiological quality and enzyme expression. Ears were harvested close to the stage of physiological maturity (around 35% moisture) and the genotypes were identified as line 1 (L1), line 2 (L2), the hybrid (HB - ♀L1 and ♂L2), and the reciprocal hybrid (HR - ♀L2 and ♂L1). For assessment of physiological quality, CDR (4x6x2) was used, consisting of four genotypes, six times of delay before artificial drying (10, 18, 24, 28, 32, and 40 hours), and two drying delay temperatures (42 and 48 °C). DIC (4x3) was used for enzymatic expression, consisting of four genotypes and three delay times before artificial drying (10, 24 and 40 hours) at 48 °C. Analysis of variance F (p < 0.05), Tukey’s test (p < 0.05), and analysis of polynomial regressions were performed on the data. Lineage arrangement affects seed tolerance to drying delay. Therefore, susceptible lines should not be used as female parents. The seeds of the line most susceptible (L2) to delay in drying exhibit less expression of α-amylase (α-AM).