Emergência de plantulas de porta-enxertos de pessegueiro submetidos a diferentes períodos de estratifica？？o

the objective of this study was to evaluate the germination and development of plants from two cultivars of the peach, 'capdeboscq' and 'okinawa', for different periods of storage, at the commercial nursery of the company frutplan mudas ltda., in pelotas, rio grande do sul, from may to december of 2009. the kernels of both cultivars were stored in paper wrappings for a period of 120 days, with the following procedures being carried out: 10 days at room temperature + 110 days of low temperature, 40 days at room temperature + 80 days of low temperature, 70 days at room temperature + 50 days of low temperature, 100 days at room temperature + 20 days of low temperature, and 120 days at room temperature, using a cold room programmed for 6 ± 2 °c. the experiment was carried out in a randomized block design, with four replications and 25 seeds per plot, in a 5x2 factorial layout (two cultivars and five periods of stratification). the variables analyzed were: the percentage of seedling emergence; plant height; trunk diameter measured at 10 cm from the soil, speed of emergence in the field (sef) and days taken to reach 70% emergence. the emergence of cv. okinawa was close to zero and therefore it was not considered when evaluating the seedlings. for the cv. capdeboscq, significant differences were found only for the variable of days taken to achieve 70% seedling-emergence, 112 to 123 days, except for that treatment with the greatest time at low-temperatures, which did not reach 70% emergence. it is concluded that periods of stratification and low temperatures offer no advantage to obtaining rootstocks of these peach cultivars, for the conditions under which the experiment was carried out.