Salinity is one of the most common and critical environmental factors that limit plant growth and reduce crop yield. The aquifers, the primary sources of irrigation water, of south Florida are shallow and highly permeable, which makes agriculture vulnerable to projected sea level rise and saltwater intrusion. This study evaluated the growth responses of two ornamental nursery crops to the different salinity levels of irrigation water to help develop saltwater intrusion mitigation plans for the improved sustainability of the horticultural industry in south Florida. Two nursery crops, Hibiscus rosa-sinensis and Mandevilla splendens, were treated with irrigation water that had seven different salinity levels from 0.5 (control) to 10.0 dS/m in the experiment. Crop height was measured weekly, and growth was monitored daily using the normalized difference vegetation index (NDVI) values derived from multispectral images collected using affordable sensors. The results show that the growth of H. rosa-sinensis and M.splendens was significantly inhibited when the salinity concentrations of irrigation water increased to 7.0 and 4.0 dS/m, for each crop, respectively. No significant differences were found between the NDVI values and plant growth variables of both H. rosa-sinensis and M.splendens treated with the different irrigation water salinity levels less than 2.0 dS/m. This study identified the salinity levels that could reduce the growth of the two nursery crops and demonstrated that the current level of irrigation water salinity (0.5 dS/m) would not have significant adverse effects on the growth of these crops in south Florida.

Rose mosaic virus disease is one of the most economically important diseases affecting roses, because a single symptomatic leaf can result in the rejection of complete shipments for wholesale or retail rose producers. It continues to be a problem in nursery production and landscapes. This 5-page document discusses the causes, symptoms, and management of this disease. Written by Susannah da Silva, Binoy Babu, Mathews L. Paret, Gary Knox, Fanny Iriarte, Barron Riddle, Matt Orwat, Shawn T. Steed, E. Vanessa Campoverde, and Svetlana Y. Folimonova and published by the UF/IFAS Plant Pathology Department, August 2018. http://edis.ifas.ufl.edu/pp338/

This new 6-page publication of the UF/IFAS Horticultural Sciences Department presents an overview on the use of different small hydroponic systems that could be implemented by home gardeners for lettuce. Recommendations on lighting, media, and other key aspects are presented in this publication as well. Written by Germán V. Sandoya, Jonael Bosques, Francisco Rivera, and E. Vanessa Campoverde.

No abstract

Florida’s ornamental plant industry flourishes due to environmental conditions that allow for a 12-month growing season. Florida leads the nation in production of tropical foliage, and Miami-Dade County ranks number one in nursery and landscape production with sales reaching $2 billion annually. The well-advertised El Niño pattern made its presence felt this past winter in south Florida with the wettest conditions since record keeping began in 1932. As a result, ornamental nursery growers contended with a higher incidence of root rots, crown rots, and foliar blight diseases, confirmed by samples submitted to the University of Florida’s Extension Plant Diagnostic Clinic in Homestead, FL. The present study focused on environmental conditions occurring over the past 4 years and included rainfall, solar radiation, and temperature variables and examined their influence on the incidence of diseases affecting ornamental plants. Results indicated Pythium and Phytophthora species as the primary plant pathogens responsible for these diseases. The drastic increase of diagnostic samples identified as Pythium and Phytophthora can be attributed to the unusually wet weather experienced. These two oomycetes are well known for causing disease under wet conditions and growers should closely monitor weather forecasts and practice preventative disease management accordingly.