Detection of Lethal Bronzing Disease in Cabbage Palms (Sabal palmetto) Using a Low-Cost Electronic Nose

Lethal Bronzing Disease (LB) is a disease of palms caused by the 16SrIV-D phytoplasma. A low-cost electronic nose (eNose) prototype was trialed for its detection. It includes an array of eight Taguchi-type (MQ) sensors (MQ135, MQ2, MQ3, MQ4, MQ5, MQ9, MQ7, and MQ8) controlled by an Arduino NANO® microcontroller, using heater voltages that vary sinusoidally over a 2.5 min cycle. Samples of uninfected, early symptomatic, moderate symptomatic, and late symptomatic infected palm leaves of the cabbage palm were processed and analyzed. MQ sensor responses were subjected to a 256 element discrete Fourier transform (DFT), and harmonic component amplitudes were reviewed by principal component analysis (PCA). The experiment was repeated three times, each showing clear evidence of differences in sensor responses between the samples of uninfected leaves and those in the early stages of infection. Within each experiment, four groups of responses were identified, demonstrating the ability of the unit to repeatedly distinguish healthy leaves from diseased ones; however, detection of the severity of infection has not been demonstrated. By selecting appropriate coefficients (here demonstrated with plots of MQ5 Cos1 vs. MQ8 Sin3), it should be possible to build a ruleset classifier to identify healthy and unhealthy samples.

The Miocene flora of Alum Bluff, Liberty County, Florida

The plant fossils of Alum Bluff, northwestern Florida, provide a unique insight into the rarely preserved Miocene flora of the eastern United States. A century has passed since the introductory treatment on the fossil leaf flora of Alum Bluff. More specimens have accumulated over the past two decades, allowing for an updated evaluation of the megafossil flora following a recent study of the palynoflora. The strata consisting of poorly consolidated sand and siltstones with intervening clay layers, here recognized as the Fort Preston Formation of the Alum Bluff Group, are considered to be of Barstovian age (16.3–13.6 Ma), based on co-occurring mammalian remains. Here we recognize 36 kinds of leaves and 10 kinds of fruits and seeds, giving a minimum estimate of at least one fungus, one fern, one gymnosperm, 38 angiosperms and 7 unknowns. We also report one new species and two new combinations. These taxa augment those already reported based on pollen from the same strata, allowing us to portray the vegetation as elm-hickory-cabbage palm forest occurring near the coastline in a deltaic, pro-deltaic, or intertidal shore face environment. The results of a climate analysis of the Alum Bluff flora, using leaf margin and leaf area, give estimates of 19.0°C mean annual temperature and 116.0 cm mean annual precipitation.

Activity patterns and roosting of the eastern blossom-bat (Syconycteris australis)

We quantified activity patterns, foraging times and roost selection in the eastern blossom-bat (Syconycteris australis) (body mass 17.6 g) in coastal northern New South Wales in winter using radio-telemetry. Bats roosted either in rainforest near their foraging site of flowering coast banksia (Banksia integrifolia) and commuted only 0.3 ± 0.1 km (n = 8), whereas others roosted 2.0 ± 0.2 km (n = 4) away in wet sclerophyll forest. Most bats roosted in rainforest foliage, but in the wet sclerophyll forest cabbage palm leaves (Livistonia australis) were preferred roosts, which likely reflects behavioural thermoregulation by bats. Foraging commenced 44 ± 22 min after sunset in rainforest-roosting bats, whereas bats that roosted further away and likely flew over canopies/open ground to reach their foraging site left later, especially a female roosting with her likely young (~4 h after sunset). Bats returned to their roosts 64 ± 12 min before sunrise. Our study shows that S. australis is capable of commuting considerable distances between appropriate roost and foraging sites when nectar is abundant. Bats appear to vary foraging times appropriately to minimise exposure to predators and to undertake parental care.

Sabal palmetto: Sabal or Cabbage Palm

The sabal palm, or cabbage palm, is native to Florida and coastal regions of North and South Carolina and Georgia and is the state tree of both South Carolina and Florida. The name “cabbage palm” comes from its edible immature leaves, or “heart,” which has a cabbage-like flavor. This 5-page fact sheet was written by T. K. Broschat, and published by the UF Department of Environmental Horticulture, July 2013. http://edis.ifas.ufl.edu/st575

Emerging Palm Diseases in Florida

Since the mid-1990s, several new pathogens and diseases have emerged on palms (Arecaceae) growing in Florida. These include two formae speciales of Fusarium oxysporum, with f. sp. canariensis causing fusarium wilt of canary island date palm (Phoenix canariensis) and a new forma specialis causing Fusarium wilt of queen palm (Syagrus romanzoffiana) and mexican fan palm (Washingtonia robusta). The texas phoenix palm decline phytoplasma (‘Candidatus Phytoplasma palmae’ subgroup 16SrIV-D), which causes a lethal yellowing-type disease, has been detected in date palms (Phoenix spp.), queen palm, and cabbage palm (Sabal palmetto). New rachis (petiole) blight pathogens include Cocoicola californica on mexican fan palm and Serenomyces species on several palm species.