2012 Spring – Research Updates

Using 1-MCP Nanosponges to Control Botrytis

Cyclodextrin-based nanosponge structures (CD-NS) are an alternative delivery method for gaseous 1-MCP which is traditionally applied in a sealed chamber. 1-MCP is an ethylene antagonist that has also been shown to be effective in reducing damage caused by Botrytis cinerea in several cut flower species. The CD-NS technology allows for an extended release of 1-MCP, resulting in benefits such as reduced dosage of active ingredient and reduced number of delivery times. This study looked at the effectiveness of a non-volatile formulation of 1-MCP delivered via CD-NS in controlling botrytis on Dianthus caryophyllus. Treatments included two concentrations (0.25 and 0.5 µL/L) of active ingredient (1-MCP) in CD-NS in a vase suspension or a 6-hour treatment with the commercial gaseous 1-MCP (3.3% a.i.). Flowers were inoculated with B. cinerea.

All 1-MCP treatments displayed slower development of B. cinerea compared to the inoculated control. The treatment of the lower CD-NS concentration performed similarly or better than the commercial gaseous 1-MCP until day 13. At day 14, the lower dose of the CD-NC was most effective and by day 15 all inoculated flowers reached 100% pathogen infection.

The study concluded that 1-MCP included in CD-NS is a promising formulation for the control of fungal diseases in cut flowers in the postharvest environment. They suggest further research to determine the mechanism of the results.

Seglie, L., D. Spadaro, F. Trotta, M. Devecchi, M.L. Gullino, V. Scariot. 2012. Use of 1-methylcylopropene in cyclodextrin-based nano-sponges to control grey mould caused by Botrytis cinerea on Dianthus caryophyllus cut flowers. Postharvest Biology and Technology. 64:55-57.

Reusing Peat in Crate-grown Lilies

Peat moss is one of the preferred substrates for the production of most greenhouse crops. Lilies, grown in the greenhouse, in shipping crates, often utilize peat in combination with other well-draining substrates such as composted bark, sawdust or coir fiber. The possible reuse of peat has at least two potential benefits: lower production cost and increased sustainability since peat is a limited natural resource. Concerns about reusing a planting substrate include disease problems, excessive accumulation of nutrient elements, unbalanced nutrient content and poor physical conditions. This study compared new and reused substrate for the production of Lilium ‘Helvetia’ plants, grown in crates in a polyethylene-covered greenhouse.

Many evaluation criteria of the cut flowers grown in new and reused substrate showed no significant difference. These criteria include fresh weight, dry weight, internode length and stem diameter. However, the stem length, leaf width and leaf length were reduced in the reused substrate. Leaf length and width were reduced by less than 1 cm, but stem length was reduced by 12 cm, from 89.2 cm in the new substrate to 77.1 cm in the reused substrate.

The study looked at physical and chemical soil properties and nutrient solution levels and determined none of the changes substantially affect plant growth. This study concluded that peat can successfully be used as a substrate for cultivation of Lilium in greenhouses for two or three cultivation cycles.

Jimenez, S., B.M. Plaza, M.L. Segura, J.I. Contreras, M.T. Lao. 2012. Peat Substrate Reuse in Lilium ‘Helvetia’ Crop, Communications in Soil Science and Plant Analysis, 43:243-250.

Anther Responsible for Flower Bud Abscission in Asiatic Lily

This study utilized Lilium flowers in part due to the easily identified floral organs. The study aimed to look at the role of the floral organs, specifically the anthers, in triggering a signal for flower bud abscission. Bud abscission is a year-round issue, particularly when lilies are forced under high temperature conditions.

Primary buds at different development stages were collected from L. x elegans ‘Red Carpet’. The researchers suggest further study with buds evaluated on the stem, but acknowledge some difficulty in evaluation by using that method.

This study concludes that, based on changes in carbohydrate content and accumulation of metabolites in the anther, improper development of the anther is a triggering factor in inducing flower bud abscission in Asiatic lilies. Furthermore, bud abscission at the critical stages of bud development is induced by lack of fructose and sucrose in the developing anther and lack of translocation of 14C sucrose to the anther from the filaments.

Hwang, S.A., P.O. Lee, H.S. Lee, J.S. Lee, M.S. Rob, M.P. Choi. 2012. Flower bud abscission triggered by the anther in the Asiatic hybrid lily, Postharvest Biology and Technology, 64:31-39