Qualidade fisiológica de sementes de milho com danos mecânicos e ardidos durante o armazenamento

Abstract

Corn has great economic importance for Brazil, being one of the most cultivated plants in many regions of the country. Among the damages found in corn seeds, this study highlights burning and mechanical damage, due to their negative effects on the quality of stored seed lots. The objective of the present work was to evaluate the physiological quality of batches of corn seeds with light burn damage, heavy burn damage and broken damage during storage. The experiment and evaluations were conducted at the Central Seed Laboratory of the Department of Agronomy (DAG) at the Federal University of Lavras (UFLA). The seeds were visually separated into: healthy seeds, seeds with light burn damage, heavy burn damage and broken damage. After separation, each of the damages was mixed with lots of healthy seeds in the following percentages: 0; 2.5%; 7.5%; 15% and 25%. Subsequently, seed lots were stored at room temperature for different storage periods (0, 3, 6, 9 and 12 months). Humidity tests in greenhouse, germination, first germination count, cold test and emergence were carried out. The data obtained were subjected to analysis of variance, polynomial regression and PCA analysis. With the results it was observed that batches of seeds with light burn damage, broken damage and heavy burn damage lose physiological quality and their storage potential after 3 months of storage and from 2.5% level of presence in a batch of seeds. The germination, cold and emergence tests show this decrease, concluding that the physiological quality of seed lots is affected by light, heavy and broken fire damage. Corn seeds stored with damage greater than 2.5% in batches reduce physiological potential.