Print version ISSN 1405-2768
DIAZ-PONTONES, David and REYES-JARAMILLO, Irma. Production and storage of acorns in Quercus hintonii Warburg (Fagaceae) from the Rio Balsas Depression, Mexico. Polibotánica [online]. 2009, n.27, pp. 131-143. ISSN 1405-2768.
Mexico is a center of diversification of oaks, which cover a great part of the mountainous areas of the country and include many endemic species. One of these, Quercus hintonii, a kind of red oak, is threatened by illegal felling and changing land use. It is distributed in the southwest of the State of Mexico, within the province of the southern Sierra Madre, subprovince of the Rio Balsas depression. Because the reforestation program in the area does not include red oak, we contribute information about the dynamics of acorn production in the oak forest and storage conditions for increasing fruit viability. Fructification of Q. hintonii is variable; years of high acorn production are followed by a period of three years during which it is scarce. This oak produced good fructification in 2004 and 2007 and reduced fructification in 2005 and 2006. Fruit dispersal is carried out mainly in the last week of August and during September. The period of germination is five days. In laboratory conditions the acorns lose viability within 30 days, the percentage of germination dropping to 4.5%. Recently collected fruit stored at 7°C and 33% relative humidity maintain their germination capacity at 94% for more than 48 days, and 88% of young nursery plants are established 21 days after the start of imbibition. The present study contributes to preserving the native species of Mexico by pointing out the storage conditions that will extend the viability of the fruits of Q. hintonii. This procedure will allow this species of red oak to be considered in propagation programs of tree nurseries growing stock for reforestation practices.
Keywords : Quercus hintonii; viability; germination; endemic specie; storage conditions.