Hybrid lilies have become an important cut flower crop in the United States. The USDA reports a wholesale value of $78,169,000 for cut flower hybrid lilies produced in the U.S. in 2004 (USDA Floriculture Crops 2004 Summary). Asiatic and Oriental hybrids are popular in the market due to their large, colorful blooms. Other hybrids such as the LA (longiflorum x asiatic) and OT (oriental x trumpet) are becoming more readily available to growers. The rapid introduction of new cultivars by breeders offers many promising but unknown cultivars for growers to plant.
The intent of this trial was to evaluate the plant growth parameters of stem length and diameter, number of blooms per stem, and time required for harvest of 10 OT Hybrid, 26 Oriental, 12 LA Hybrid, and four Asiatic hybrid lily cultivars. The trial was conducted at the North Mississippi Research & Extension Center in Verona, Mississippi. Verona is in hardiness zone 7b and AHS heat zone 8. In 2005 the average maximum and minimum temperatures from May 11-20 were 83.8F and 59F, respectively, and from June 11-20 they were 85.4F and 65.6F.
The bulbs, obtained from Zabo Plants, were planted in bulb crates (14.5 x 22 x 8 inches) on March 30, 2005. The bulbs were placed on two inches of medium in the crate and then covered with six inches of medium. The growth medium used in the crates was a 4:1 mixture of pine bark screened to a 3/8” maximum and Metro Mix 366. Ten pounds of lime and 13.5 lbs. Osmocote Plus (15-9-12) 8-9 month Southern Formula were added to each cubic yard of media. The crates and bulbs were placed in an uncovered cold frame immediately after planting. A 47% shade cloth was installed on the cold frame when lily shoot growth emerged from medium. The crates were watered by hand as needed. Twelve bulbs were planted in each crate. More bulbs could have been planted in each crate, but only 12 were planted to aid in identifying the cultivars within the experimental design. Some plants did not grow straight up from the bulb and the stem had to be traced from the media surface to the bulb to accurately identify the cultivar.
Lily stems were harvested as soon as color appeared on the first bloom. Stems were cut at the soil line, and stem diameters were measured at the base of the stem. The stem length was measured from the base of the stem to the upper edge of the bloom.
The harvest period for the lilies in this trial that were planted on March 30 started on June 8 and ended July 8, 2006. The LA Hybrid, Asiatic, and OT Hybrids, ‘Ohara’ and ‘Go for Gold’, cultivars in this trial required the fewest days from planting the bulbs in the crates until harvest, 70.0 – 76.5 days. The Oriental hybrids required the most days to grow to harvest, 82.0 – 97.5. Among the Oriental cultivars, ‘Armonia’ and ‘Valdemar’ required the fewest days to harvest. The Asiatic and LA hybrids were harvested from June 8 – 14. The Oriental hybrids were harvested from June 20 – July 8 and the OT hybrids were harvested from June 8 – 28.
The Oriental cultivar, ‘Pranese’, produced stems statistically longer than all other cultivars except ‘Natal’. The cultivars ‘May Tay’, ‘Lucera’, and ‘Caruso’, at 26 inches, were the shortest Oriental cultivars in the trial. The stem length of ‘Tinos’, an Asiatic hybrid, averaged 23 inches and was the shortest lily in the trial.
In general, the stem diameters of the OT Hybrid cultivars were greater than the other lilies in this trial. The basal stem diameter of ‘Alusta’ was the largest in the trial at 0.77 inches. ‘Caruso’, ‘May Tay’, and ‘Cornas’, Oriental hybrids, produced the smallest stem diameters in the trial, 0.32 inches.
The OT hybrid ‘Alusta’ produced ten blooms per stem which was the highest number of blooms of all the cultivars in this trial. The cultivars ‘Soprano’ and ‘Belladonna’ had the fewest blooms per stem in the OT hybrid group. The Asiatic cultivars averaged 4 blooms per stem. The number of blooms in the LA hybrid cultivars ranged from 2.8 to 7 blooms per stem. ‘Pantanal’ produced the most blooms of the LA Hybrid cultivars at 7 per stem. The number of blooms for the Oriental hybrids ranged from 1.7 to 7.5.
All of the hybrid lilies in this trial produced acceptable stem lengths and diameters. ‘Brenta’ was the only cultivar planted that did not produce blooms. Considerations of bloom color, number of blooms per stem, and harvest timing will guide growers in cultivar selection. This trial was conducted during the spring before the summer heat could affect plant growth. Bulbs stored in a cooler for a later planting date could well be affected by longer day lengths and higher temperatures.
The authors thank Mr. Ko Klaver of Zabo Plants for supplying the lily bulbs used in this experiment.