PREGERMINATIVE TREATMENTS IN SEEDS OF TWO SPECIES OF THE Coffea GENUS

Abstract

Coffee seeds have slow and asynchronic germination, which
increases the time needed to obtain seedlings, and the expenses
associated. A pregerminative treatment (PT) was defined which
decreases the germination time in seeds of Coffea arabica L. var.
Colombia and Coffea canephora P. var. Robusta. Five pregerminative
treatments in water were applied to seeds without endocarp: T1)
immersion for 24 hours; T2) scraping plus immersion for 24 hours;
T3) immersion for one hour at 40 °C; T4) immersion for 48 hours;
and T5) scraping plus immersion for 48 hours. Subsequently, they
were sown in two substrates (sand and peat-moss). The treatments
had three replicates with 25 seeds as experimental unit, organized
into a completely randomized design with factorial arrangement. The
variables evaluated were: days to start of germination (DIG), speed of
emergence (VE), and percentage of emergence (PE). In Coffea arabica,
the PT that decreased the germination period was T1, obtaining
seedlings at 22 days, with greater vigor with a VE of 0.55 emerged
seedlings per day, and increased PE to 59, 92, and 97% on days 30,
40, and 50, respectively. In Coffea canephora, T1 presented 0.40 VE
and PE of 42% at 30 days and 73% at 50 days, while T2 increased PE
at 40 and 50 days by 70 and 81%, respectively. The best substrate was
sand, which decreased the germination period of Coffea arabica and
Coffea canephora to 26 and 23 days, increased VE to 0.53 and 0.35
emerged seedlings per day, respectively, and had PE of more than
70% after 50 days in both species.