Heat treatment and germination of seeds of interspecific hybrid between American oil palm (Elaeis oleifera (HBK) Cortes) and African oil palm (Elaeis guineensis Jacq.)

The oil palm (E. guineensis) is the African origin and the world's leading source of vegetable oil. The interspecific hybridization of the African oil palm (E. guineensis) with American oil palm (E. oleifera) aims to improve resistance to diseases, to improve oil quality and lower plant height. EMBRAPA (Empresa Brasileira de Pesquisa Agropecuaria, Brazilian Corporation of Agricultural Research) has developed the first Brazilian interspecific hybrid cultivar (HIE) between American oil palm and African oil palm. The procedures adopted for commercial seed germination assessment have shown an average germination rate of 32%. The objective of this work was to assess the effect of the period of heat treatment and seed water content that are ideal for breaking dormancy and obtaining maximum germination. A completely randomized design was adopted, in a 4 x 3 factorial design, with four ranges of moisture contents: 18-19; 19-20; 20-21 and 21-22%, and three periods of heat treatment: 55, 75 and 100 days, with three replicates of 500 seeds. The percentage of germination, the first count and the germination speed index were assessed. To break dormancy and germination, the hybrids seeds of HIE, oleifera versus guineensis, should have their water content adjusted to values between 19 and 22%, and be subjected to heat treatment at a temperature of 39 +/- + 1 degrees C and relative humidity of approximately 75% for 75 days.