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Abstract
The effect of temperature on development of ‘Cabernet Sauvignon’ berries was examined in growth cabinets beginning 3 weeks after flowering and terminating 6 weeks after the start of stage III. High temperature, 35/30°C, reduced the amount and duration of berry growth during stage I; it lengthened stage II by inhibiting the onset of stage III. Final berry size was irreversibly reduced by high temperature during stage I. The duration of stage II was also lengthened by lowering the day/night temperature during stage I from 25/20 to 18/13°C. Maximum berry size was attained most rapidly at the intermediate and most slowly at high temperature. Generally, stages I and II were more sensitive to temperature than stage III.
Final berry weight was lowest at 35/30°C. The concentration of total soluble solids was low when both stages II and III were at 35/30 and high when stage I or both stages I and II were at 35/30 and subsequent growth at 18/13. Once stage III had started, temperature had little effect on berry size or total soluble solids. Acidity was highest when all stages of development were at 18/13 and was reduced by high temperature at any stage of development.
Abstract
Mechanical and chemical methods for improving the branching of Crassula argentea Thunb., Kalanchoe tomentosa Bak., and Columnea microphylla Klotzsch and Hanst. ex Orst. were examined. C. argentea did not respond to hand-pinching, atrinal, or BA treatments. K. tomentosa produced 44% more branches when treated with 50 ppm BA but were relatively unaffected by atrinal or hand-pinching. C. microphylla typically branched only from the basal nodes; however, 59% more branching was observed when treated with 500 ppm atrinal. Hand-pinching or BA did not affect branching of Columnea. Atrinal also retarded stem elongation of C. microphylla; the inhibitory effect of 500 ppm was comparable to the reduction in stem length caused by hand-pinching. Chemical names used: (2,3:4,6 bis-O-(1-methylethylidene)-O-L-xylo-2-hexulofuranosonic acid, dikegulac sodium, atrinal), N-(phenylmethyl)-2H-purin-6-amine (BA).
With increased mobile device usage, mobile applications (apps) are emerging as an extension medium, well suited to “place-less” knowledge transfer. Conceptualizing, designing, and developing an app can be a daunting process. This article summarizes the considerations and steps that must be taken to successfully develop an app and is based on the authors’ experience developing two horticulture apps, IPMPro and IPMLite. These apps provide information for major pests and plant care tasks and prompt users to take action on time-sensitive tasks with push notifications scheduled specifically for their location. Topics such as selecting between a web app and a native app, choosing the platform(s) for native apps, and designing the user interface are covered. Whether to charge to download the app or have free access, and navigating the intra- and interinstitutional agreements and programming contract are also discussed. Lastly, the nonprogramming costs such as creating, editing, and uploading content, as well as ongoing app management and updates are discussed.
Mobile device applications (apps) have the potential to become a mainstream delivery method, providing services, information, and tools to extension clientele. Testing, promoting, and launching an app are key components supporting the successful development of this new technology. This article summarizes the considerations and steps that must be taken to successfully test, promote, and launch an app and is based on the authors’ experience developing two horticulture apps, IPMPro and IPMLite. These apps provide information for major pests and plant care tasks and prompt users to take action on time-sensitive tasks with push notifications scheduled specifically for their location. App testing and evaluation is a continual process. Effective tactics for app testing and evaluation include garnering focus group input throughout app development and postlaunch, in-house testing with simulators, beta testing and the advantages of services that enhance information gained during beta testing, and postlaunch evaluations. Differences in promotional and bulk purchasing options available among the two main device platforms, Android and iOS, are explored as are general preparations for marketing the launch of a new app. Finally, navigating the app submission process is discussed. Creating an app is an involved process, but one that can be rewarding and lead to a unique portal for extension clientele to access information, assistance, and tools.
The eriophyid mite, Phyllocoptes fructiphilus, vectors the causal agent, Rose rosette virus (RRV), that results in rose rosette disease. Parts of the southeastern United States have remained free of the disease, except for infected plant material introductions that were eradicated. A survey of sampling points through Alabama, Georgia, and Mississippi (n = 204) revealed the southeastern border of RRV. The presence of RRV in symptomatic plant tissue samples (n = 39) was confirmed by TaqMan-quantitative reverse transcription polymerase chain reaction (RT-qPCR). Samples were also collected at every plot for detection of eriophyid mites, specifically for P. fructiphilus. Three different species of eriophyid mites were found to be generally distributed throughout Alabama, Georgia, and Mississippi. Most of these sites (n = 60) contained P. fructiphilus, found further south than previously thought, but in low populations (<10 mites/gram of tissue) south of the RRV line of incidence. Latitude was found to be significantly correlated with the probability of detecting RRV-positive plants, but plant hardiness zones were not. Plot factors such as plant size, wind barriers, and sun exposure were found to have no effect on P. fructiphilus or the presence of RRV. The reason for the absence of RRV and low populations of P. fructiphilus in this southeast region of the United States are unclear.
Extension and research professionals in the southeastern United States formed the Southern Nursery Integrated Pest Management working group (SNIPM) to foster collaboration and leverage resources, thereby enhancing extension programming, increasing opportunity, and expanding the delivery of specialized expertise to nursery crop growers across a region. Building a productive and lasting working group requires attracting a group of research and extension faculty with complementary expertise, listening to stakeholders, and translating stakeholder needs into grant priorities to help solve problems, all hallmarks of effective teamwork principles. SNIPM has now grown to include 10 U.S. states and 11 institutions and has been awarded seven grants totaling $190,994 since 2009. A striking benefit of working group membership was observed over time: synergy. Greater awareness of individual expertise among SNIPM members, each of whom were focused on different aspects of the nursery production system stimulated multistate extension publications, electronic books (eBooks), mobile device applications (apps), popular press articles, and spin-off research projects when separate foci were combined and directed toward complex challenges. Deliverables achieved from this faculty collaboration include nine peer-reviewed publications, four manuals and books and 23 book chapters, and a combined total of 11 abstracts, conference proceedings and extension publications. To date, the return on investment for SNIPM is one deliverable produced to every $2265.89 in grant funding. SNIPM has also been honored with multiple American Society for Horticultural Science publication awards as well as the Southern Region Integrated Pest Management Center Bright Idea Award for the quality and originality of their project outputs. Continuing to work together toward common goals that bridge technology and serve the nursery industry while supporting each individual member’s program will be crucial to the long-term success of this working group.