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Ornamental plant producers often rely on chemical control to manage insect pests. However, cultural practices, such as pruning, can influence plant architecture which may, in turn, affect pesticide penetration. Spray penetration was studied to determine the effect of canopy density on beneficial insect survival following insecticide application and to better understand the implications of canopy density on pest management. Regardless of canopy density or plant species, the interior position of the canopy received less than 8% spray coverage. The middle position of sparse canopies received 288 to 513% more coverage than the middle position of dense canopies. The middle and interior position of dense canopies protected greater than 50% of the convergent lady beetle (Hippodamia convergens (Guérin-Méneville) population while only the interior position of dense canopies protected greater than 50% of green lacewing (Chrysoperla rufilabris Burmeister) populations. Index words: beneficial insect, nursery crop, pesticide, plant architecture, woody ornamental. Species used in this study: China Girl® holly (Ilex ×meserveae ‘Mesog'); ‘Alice' Oakleaf hydrangea (Hydrangea quercifolia Bartr. ‘Alice'); convergent lady beetle [Hippodamia convergens (Guérin-Méneville)]; green lacewing [Chrysoperla rufilabris (Burmeister)]. Chemicals used in this study: carbaryl (1-naphthyl N-methylcarbamate, Sevin® SL, Bayer CropScience, Durham, NC).

The genus Vaccinium represents an increasingly important group of plants for the U.S. green industry. In 2012, blueberries (Vaccinium sp.) ranked the second most important berry crop in the U.S. with a total crop value over $780 million. The popularity of blueberries creates opportunities as well as challenges for nursery crop producers. This article presents a review of current nursery production practices of blueberry and explores the challenges and opportunities for nursery crop producers, including pesticide use during nursery production of an edible crop, and discusses current research relevant to the green industry. Needs for additional research and opportunities for breeding are presented. Blueberries are Ericaceous plants and have very specific cultural requirements. This review presents the culture, as well as insect, mite, and disease control from an integrated pest management (IPM) approach for several blueberry species. A serious threat to the blueberry market, spotted wing drosophila (Drosophila suzukii Matsumura) is discussed to provide information needed by commercial producers and landscape managers to address client and customer questions. This review also highlights the most relevant blueberry selections for container production in the southeastern United States.

Cutting-propagated ‘Alice’ oakleaf hydrangea (Hydrangea quercifolia Bartr.) often produces a few vigorous branches with apical dominance, thus suppressing growth of other branches. As a result, the maturing canopy is sparse and develops asymmetrically, rendering plants unappealing to customers. For this reason, growers prune or apply plant growth regulators (PGRs) to encourage more branching, thereby producing a more desirable product. Propagation through tissue culture may provide another option to increase branching as an outcome of habituation. Habituation occurs when plant cultures continue to respond to a hormone that is no longer being supplied and, in turn, frequently leads to more branching. We evaluated oakleaf hydrangea growth as affected by propagation technique [tissue-cultured (TC) and cutting-propagated (CUT)] and PGR (cyclanilide and benzyladenine) application during container production. Nontreated TC plants had more branches longer than 15.2 cm (6 in) compared to nontreated CUT plants in 2008, although not in 2010. In both years, single applications of cyclanilide did not affect total branch number but two applications increased total branch number compared to nontreated plants, averaged over propagation technique. Plants treated with benzyladenine had similar or fewer total branches compared with nontreated, hand-pruned, and cyclanilide-treated plants (one or two treatments). Propagation technique did not consistently influence response to PGRs.

The genus Viburnum encompasses a group of about 150 species of evergreen, semi-evergreen or deciduous trees and large shrubs. Viburnums are native to temperate, subtropical and tropical areas of southeastern Asia, eastern North America, Central America, the Caribbean and parts of South America. Native and nonnative Viburnum species have become prominent landscape plants in the southeastern United States due to their beauty, utility, relative ease of maintenance and broad adaptability to the region's climate and soils. Efficient management of viburnum pests to maintain healthy viburnum plants in nurseries and landscape settings is crucial for sustaining the economic competitiveness and profitability of green industry professionals competing in the horticulture marketplace. Diversity of species within the genus, however, is vast, and can contribute to many host-pest complexes that differ among growing environments and cause severe economic or aesthetic losses. Additionally, some abiotic disorders may mimic biotic damage or may render viburnum more susceptible to pests and diseases. This review focuses on viburnum culture in production and landscape settings with an emphasis on major insect and mite pests, plant diseases and abiotic disorders affecting management of Viburnum species in nursery and landscape settings.

The genus, Magnolia, encompasses a group of about 240 species of evergreen or deciduous trees and large shrubs. Magnolias are native to temperate, subtropical and tropical areas of southeastern Asia, eastern North America, Central America, the Caribbean and parts of South America. Native and nonnative Magnolia species have become prominent landscape plants in the southeastern U.S. due to their beauty, utility, relative ease of maintenance and broad adaptability to the region's climate and soils. Species introductions, breeding and selection programs over the last 50 years have produced superior selections with improved flowering, new flower colors and ornamental foliage and buds often featuring brown, copper or gold indumentum. Magnolia health and pest management is sometimes overlooked in both landscape and production settings because magnolia is considered to have relatively few pest and disease problems. Some abiotic disorders may mimic biotic damage or may render magnolia more susceptible to pests and diseases. When they occur, abiotic disorders, pests or diseases on magnolia can cause significant economic or aesthetic losses. This review focuses on magnolia culture in production and landscape settings with an emphasis on major pests, plant diseases and abiotic disorders affecting management of Magnolia species.

Hydrangeas are an increasingly popular group of shrubs which are prized for their showy inflorescence. Nursery crop producers grow numerous hydrangea varieties for the landscape and florist markets. Hydrangeas are typically hand-pruned during propagation and production to promote compaction and to increase the number of branches which has potential for increasing blooms and marketability. Identifying a plant growth regulator (PGR) treatment that effectively improves the architecture of hydrangeas became an IR-4 Project research priority for 2011. Research evaluating Augeo (dikegulac sodium), Configure (benzyladenine) and Florel (ethephon) shows worthwhile results. Augeo (800 and 1600 ppm) significantly increased branching compared to untreated pots of florist varieties Hydrangea macrophylla ‘Merritt's Supreme’ and landscape varieties H. macrophylla ‘Nikko Blue’ and H. paniculata ‘Limelight’. Configure (300 ppm and 600 ppm) and Florel (500 and 1000 ppm) did not significantly improve branching in five of six trials compared to the control. Significant chlorosis on Augeo treated plants was observed initially but this diminished by 6 weeks after treatment (WAT) for four out of six trials. Little to no crop injury was observed with Configure or Florel treatments to hydrangea liners. This research shows promise for identifying a plant growth regulator treatment to meet the demand for improved branching on hydrangea.