July 2008

Pacific Plug & Liner’s Interspecific Nemesia Trial By Ryan Hall

The California Pack Trials is a whirlwind week where growers, brokers and industry professionals tour California from north to south looking for new varieties they can offer their customers. Pacific Plug & Liner hosts a stop on the Pack Trials, and we have the pleasure of accommodating each group, large and small. At this stop, our company helps growers and brokers by consolidating a key genus into a complete, unbiased comparison trial. This has been a great tool for our visitors, allowing them to take detailed notes on superior varieties. They can then come back to their customers with information about plants they have actually seen compared side by side. For 2008, we decided to trial a new set of varieties of a commonly grown genus, nemesia.

Trialing New Nemesia Type

Recently, there has been a new type of nemesia being bred and marketed; we typically refer to them as interspecific-type nemesias. This type of nemesia is notable for its range of reds, yellows and oranges, colors that are uncommon in traditional nemesia lines. Growers familiar with the seeded varieties such as the Nebula series and 'Danish Flag' have seen the differences in color and overall habit. Breeders have brought a number of vegetative series to market that capture the new colors and large flower size and add some needed improvements to habit and controlled growth.

Pacific Plug & Liner also wanted to trial this type of nemesia to evaluate cultural challenges we have observed in our finish production. We wanted to identify whether crop problems were specific to certain genetic lines or colors. Our results were not definitive, but we made the following observations:

• Interspecific varieties prefer bright and cool conditions with good air movement.
• Both upright and trailing varieties need pinching and growth regulation to produce the best plant in our climate.
• The upright selections in general had the best performance in our 4-inch container trial and had the least amount of die-off.

We did observe virus-like symptoms in certain plants. Necrosis and die-off happened in almost every color we trialed. One breeder noted that these types of nemesia are very susceptible to virus infection and many cultural problems stem from this infection. Proper handling and sanitation at a grower level will help avoid cross contamination with other varieties. Growers should also closely monitor their cutting supply and notify suppliers when plant material is suspect of infection.

Distinguishing Among Series

Pacific Plug & Liner trialed the following series: Sunsatia (Proven Winners), Serengeti (Selecta First Class), Angelart (Fides North America) and Nemesis (Westhoff). There were notable differences among all the series, with each line having superior selections. All series except for Angelart had both trailing and upright or mounding varieties.

All varieties were treated the same culturally. We planted 105 rooted liners in 4-inch containers in week five. Plants were pinched once and received a 2-ppm drench of paclobutrazol. Plants were grown inside the greenhouse under acrylic glazing and had night temperatures at 50¡ F and day temperatures up to 75¡ F.

Angelart (Fides North America). This series stole the show at the trial. Angelart was the most uniform series. All colors were well suited to container production and branched well with a single pinch. The flowering of this series was also very uniform; each color was in full bloom at the time of the trial. The following colors were superior in the series: Pear, Melon and Cherry.

Sunsatia (Proven Winners). Sunsatia has been around for the longest when looking at vegetative series. Some notable standouts showed through in our trial. Raspberry and Mango both had strongly upright, well-branched habits, making them ideal for container production.

Serengeti (Selecta First Class). The Serengeti series was similar to that of the Sunsatias and had some standout selections in their upright varieties. The most notable in our trial was 'Serengeti Upright Cream'. This selection had cream flowers with the throat flushed with lavender.

Nemesis (Westhoff). This series is dominated by vigorous trailing selections, making Nemesis a series ideal for mixed combos and basket plantings. Red Fancy had a respectable habit with a novel orange and red bicolor flower that garnered a lot of attention from visitors.

Final Thoughts

Overall, interspecific nemesia is another crop that growers can add to the ever-growing line of vegetative annuals. These nemesias bring a unique look and color range to the market but can also present some cultural challenges. As we displayed our trial, a new series worth mentioning came to market: The Supernesias from Danziger were very impressive, with huge flowers and a full color range. We also heard the Magma series from Syngenta Flowers is being reworked and should be available again to growers soon.

For those of you visiting us in 2009, look forward to a comparison trial of vegetative lobelia and scaevola.