LILY BREEDING AND INTRODUCTION IN MODERATE CLIMATES
In the Baltics, climate conditions vary considerably within small distances — from heavy precipitation and limited sunshine to moderate, dry and warm temperatures. The coastal regions are affected by the Gulf Stream which is a moderate influence on Northeastern Europe as a whole. What is for lily breeders possible there, is possible anywhere in the world where moderate climates prevail.
Moderate zones may be particularly ideal to breed for development of unusual and disease-free hybrids. Winters may be plagued with frequent thaws that might be followed by deep freezes - critical for the survival of planted bulbs. Only hybrids that can survive such extreme environments and are able to live through late spring, at times even mid-summer frosts can do well. Early autumn frosts are also frequent and this may shorten the growing season.
To develop hardy and attractive plants, breeders are forced to develop individual techniques suitable for specific areas. The experiences by lily breeders in the Baltic proves that climatic disadvantages can be overcome and hardy and decorative hybrids have been successfully developed.
The climate in the Baltics was affected by environmental pollution. From late July throughout August it may be wet and cool. These conditions may prevail also in the spring and promote spreading of Botrytis elliptica and inflict serious damage throughout the season. In moderately cool zones — particularly, because the fungi survive the winter in sclerotia which has formed on the leaves the previous season, Botrytis elliptica is the most widely spread disease. To a certain extent the problem may be eased by planting in a well-drained site where there is a good circulation of air — so the foliage can dry off quickly after rain or a heavy dew.
Polyploids, because of high chromosome count, prove to be of a great advantage. Polyploids prove to be particularly suitable to moderate climates. Their strong stems, large and thick petals, thick and large leaves with shiny, waxy surfaces seem to stand well against damage and disease.
To obtain seeds in polypoid hybrids, it may be necessary to pollinate in greenhouses where high temperature can be achieved and maintained, or to use pollen mixture to facilitate fecundity of the ovules, or to apply chemical substances on the stigma to enhance pollination, or to use in vitro fertilization.
My personal achievement is 'Jumprava' (registered with the International Lily Register (ILR), 4n — presently, the only tetraploid known in Latvia, with large, light yellow, star-shaped flowers, brown anthers, and a strong velvety stigma. Perianth segments are thick, waxy, enduring. Foliage of glassy, dark green leaves remains green until late in the autumn. Flowers early July — earlier than any other polyploid developed in the Baltics.