Processing Eucalyptus cloeziana seed lots to improve purity, germination and vigor

Eucalyptus cloeziana is one of the highest-density wood species offering significant added value, frequently used in the construction and furniture industries. Despite its suitability, it may be overlooked on account of its propagation difficulties due either to its low rooting cutting capacity or to its seeds having a low germination rate perhaps attributable to the high proportion of indistinguishable impurities within the seed lots. This study aimed to develop an efficient technique for Eucalyptus cloeziana seed processing to increase the physical purity and, consequently, the physiological quality of the seed lot. Three seed lots, separated by size in sieves with 1.18, 1.00, and 0.84 mm square openings, were used. X-ray analyses were carried out, the number of normal seedlings and germination rate identified and the percentage and speed of seedling emergence under greenhouse conditions ascertained. The greenhouse evaluation showed that the seed retained in the 1.18 mm sieve presented viability and vigor twice that of the control. Therefore, the processing technique by size classification is efficient in terms of improving the physical and physiological performance of Eucalyptus cloeziana seed lots.