Research concerning flowering period in crosses

Felicitas Svejda published a paper in Euphytica, volumn 26, pages 697-701, (1977), “Breeding For Improvement of Flowering Attributes of Winterhardy Rosa Rugosa Hybrids”.

The following are some of the findings that I felt are particularily interesting:

  1. Among the 75 two year old seedlings there were only 11 “keepers” if the “keep” criteria was to keep only seedlings that had a flowering period of 12 to 16 weeks (the plants were observed for periods of from 13 to 16 weeks depending on the year). The third year, 26 seedlings had periods of bloom in that range. Thus, “keeper” selection after only two years would of resulted in throwing out 15 seedlings that would have been “keepers” if year three selection would have been used.

  2. Four of the seedlings still had not bloomed by the end of the second year. All third year seedlings had bloomed.

  3. Eleven seedlings were studied in detail concerning their flower production. The length of the flower production (in general) was not correlated with the number of flowers produced. However, the 4 seedlings with the longest flower production also produced the most flowers.

  4. Four seedlings had longer flower production periods than the longer flowering parent. Only one seedling had a shorter flower production period than the shorter flowering parent.

  5. Four seedlings produced a greater number of flowers than the more prolific parent. Five seedlings produced fewer flowers than the less prolific parent.