Impact of Production System and Cultivar on Yields of Roselle (Hybiscus sabdariffa) Leaves and Calyces

Impact of Production System and Cultivar on Yields of Roselle (Hybiscus sabdariffa) Leaves and Calyces

Summary

A thorough search of the internet and via contacts in the seed industry revealed that there is only one cultivar of Roselle readily available from one commercial supplier, and in the 2011 season in limited supply. Additionally, contacts with the Asian Vegetable Research and Development Center – Taiwan were willing to supply a limited number of cultivars for trialing, but were reached too late in the season to obtain seed in time to grow. Therefore, due to challenges in obtaining an adequate supply of seed for production in 2011, only one observational trial was able to be established with Morris Gbolo at his farm in Galloway Township, NJ. That trial allowed preliminary, but limited due to weather extremes, comparison of Roselle var. Thai Red grown from transplants on either black plastic mulch or bare ground, both with overhead irrigation. In order to have an adequate seed supply for the 2012 season, 16 Roselle var. Thai Red plants have been moved into a greenhouse for the winter to produce seed.

Objectives/Performance Targets

A smaller than planned demonstration trial was established on the Atlantic County, NJ farm operated by Mr. Morris Gbolo, to compare traditional multiple-harvested plantings on both bare ground and plastic mulched plots. Approximately 80 roselle plants were transplanted into either a single bare ground or plastic mulched flat bed plot on 7/15/2011. The single row demonstration plot was planted alongside several beds of previously seeded roselle that Mr. Gbolo had obtained from another seed source. The plots were irrigated as needed with overhead sprinklers.

Plots to be replicated at the Rutgers Agricultural Research and Development Center – Upper Deerfield, NJ were not able to be established this year due to the limited amount of seed we were able to obtain. Sixteen plants grown in pots during the summer season were transferred to a RAREC greenhouse in late Fall for production of seed in order to have enough for the 2012 season.

Likewise, separate cultivar evaluation studies were not established in 2011 due to the limited variety of commercially available cultivars and the lateness in obtaining cultivar samples from the seed banks at the Asian Vegetable Research and Development Center (AVRDC).

No outreach efforts were attempted with the limited scope of the project in this first season.

Accomplishments/Milestones

Mr. Gbolo made some preliminary measurements of yields of leaves and shoots in early September. However, due to excessive rains in August and early September (Tropical Storms Irene and Lee and other smaller storms) plants grown in the plastic mulched bed began to succumb to root rots that eventually killed most of those plants, limiting the harvest period and overall yields.

Impacts and Contributions/Outcomes

The impacts of this project following this preliminary season are the following observations:

• seed quantity and variety are limiting factors to increasing production of roselle,
  roselle var. Thai Red does not show any tolerance to root diseases and/or to being grown in wet soils, indicating raised bed production would likely improve production in poorly drained soils.

• Roselle plant succombing to excessive soil moisture under plastic mulch.
• Roselle calyx.
• Morris Gbolo transplanting roselle

Collaborators: