Germinação de sementes e vigor de mudas de brs Manicoré (elaeis oleifera x e. guineensis)

Abstract

Embrapa developedin 2010 the first commercial hybrid between caiaué specie (Elaeis oleifera) and oil palm (E. guineensis) (HIE OxG) in Brazil, called BRS Manicoré, as an alternative to palm oil production in incidence areas of the anomaly lethal yellowing. For Elaeisgenre, although there is an established protocol on a commercial scale, the seeds need procedures to overcome dormancy, obtaining sprouted seedsofgood quality, that is essential for establishing a stand. The study aimed to evaluate: I. Exposure time and effect of hydrogen cyanamide (CH) on seed germination of HIE OxG; II. Effective concentration of CH and germination percentage; III. Effect of germination speed in the development of seedlings in the nursery pre-stage. The experiments were carried out at Embrapa Western Amazon, using seeds of commercial lots, freshly harvested and processed.The water content of the seed was adjusted to 15-16% and 20-21%. For all experiments,the design was randomized blocks with 500 seeds. Experiment 1. Comprised of five treatments and four replications, with immersion in CH solution in the concentrations of 2.0 and 2.5% for 24 and 48 hours and thermal treatment (TT) (at 39 ° C ± 1 for 75 daysand humidity air around 70%); Experiment 2. It wereevaluated six treatments and four replications, with soaking seeds in CH solution for 24 hours at concentrations of 0.5, 1.0, 1.5 and 2.0% of the commercial product; soaking in water and TT. Experiment 3. Four treatments (screening / rating) at 7, 14, 21 and 28 days after germination room entry in five replicates of eight seedlings. After treatment, seeds were immersed in water for nine days and then keptin a growth room (25 ° C to 27 ° C). Smaller percentages of germinated seeds (PSG) were obtained with immersion on CH for 48hours. PSG seeds soaked in water was less than the values obtained in the treatments with CH and TT. The plantlets from the first and second screening showed greater stem diameter. Thegreatest heights of the seedlings were obtained from the seeds of the second and third screening. Loweraverage fresh matter of shoot first and fourth screening and fresh weight of root were found in the seeds of the first, third and fourth screening. It is concluded that hydrogen cyanamide has a positive effect on the germination of seeds of BRS Manicoré, however, its use is not recommended to replace the TT by the lowest percentage of germinated seeds. For the experiment where seedling vigor were evaluated in pre-nursery, the results showed a trend toward greater vigor to seedlings from seeds of the second (14 days) and third screening (21 days)