Fourth-Year Results from a Clonal Test of Loblolly Pine

In November and December 1998, two experimental plantings were established using rooted cuttings from 450 clones of eight unrelated full-sib families of loblolly pine (Pinus taeda L.). Clones from four of the families (282 clones) were planted in South Carolina and clones from the other four families in Florida (168 clones). Both tests were laid out as randomized complete blocks with nine blocks and one ramet/clone/block. Height, survival and rust resistance were measured annually and diameter was measured at age four. Best Linear Unbiased Prediction of clone genetic values were estimated for height and volume at age four. Estimated genetic gains from various clone selection strategies, the effect of increasing or decreasing the number of ramets for testing on genetic gain, height age-age and trait-trait genetic correlations were estimated. Estimated genetic gain was highly sensitive to the intensity of clonal selection. Selecting the single best clone from each test resulted in an estimated gain of 13% (SC) and 14% (FL) in height at age four over the test average (all the clones). The single best clone from each family at each site (four in total) resulted in an estimated gain of 10% (SC) and 10% (FL). However, if six clones were selected from each family (twenty-four in total), gain was reduced to 8% (SC) and 6% (FL) in height. The genetic correlations between height at age one and height at age four were low (0.60 at SC, 0.58 at FL), but increased to 0.96 (SC) and 0.97 (FL) between heights at ages three and four. Simulations using test parameters showed that estimated gain increased with the number of ramets tested up until ten ramets per clone, but did not increase appreciably with ramet numbers above ten. Moreover, approximately 90% of the gain could be obtained using only six ramets. These data, additional details and the implications of these results will be discussed.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

A Ten-Year Review of the Southeast U.S. Green Industry, Part II: Addressing Labor Shortages and Internal and External Factors Affecting Business Strategies

Agriculture can be a very labor-intensive industry. While some types of crops and livestock operations have become highly mechanized and have incorporated precision agriculture technologies in planting, fertilizing, and harvesting activities, specialty crops, including nursery crops, still rely heavily on manual labor. For example, planting, pruning, fertilizing, staking, weeding, harvesting and pulling orders are often done manually by workers due to the diversity of products (e.g., size, shape), fragility of the product, and low consumer tolerance for aesthetic damage on plants. Labor accounts for approximately 40 percent of nursery production costs (Mathers et al., 2010; Hall & Ingram, 2014). However, a business model that depends on maintaining the current labor force may not be successful. Current surveys reveal that a shrinking workforce is becoming a greater barrier for producers. For example, Tennessee growers report that labor-related challenges including hiring and retaining domestic employees are increasing. A common refrain from Tennessee nursery owners is that locally sourced employees routinely do not return from lunch on their first day, if they show up at all. Tennessee producers’ experiences are not unique. Nationally, nearly 80 percent of nurseries indicated that labor is their greatest challenge, and more than 50 percent stated the lack of a qualified workforce limited their ability to fill vacant positions (McClellan, 2018). Given the persistent and widespread labor scarcity that U.S. nurseries are facing, growers may need to adopt strategies that improve efficiency and production to best utilize their limited workforce. In Part I of this series of publications, A Ten-Year Review of the Southeast U.S. Green Industry, Part I: Labor and Firm Characteristics, we explored annual sales, product types and workforce demographics. In Part II, we discuss what actions nurseries are taking to address the labor shortage and the role other factors and issues have on business decisions that could affect the future sustainability of the U.S. green industry. Growers and other industry stakeholders can use these results to evaluate strategies to address and alleviate labor issues. These results may also help decision makers within nurseries identify solutions, including technologies that align with their unique production situations. The results could also help elected officials, state and federal agriculture entities, and trade associations identify opportunities to develop new, and expand existing, cost share programs and similar initiatives that support nursery producers

A Theory of Planned Behavior-Informed Evaluation of Growers’ Intent to Use Automated Nursery Technologies

Labor scarcity and rising production costs due to increasing labor wages and benefits are key concerns among nursery growers. Automated nursery technologies are a means to address labor challenges, but they are not widely adopted. The research objective was to use the Theory of Planned Behavior to evaluate nursery growers’ intention of using automated technologies in their operations to support future educational initiatives. Using a mixed-mode survey, four technology clusters, or a grouping of connected ideas, were examined: Irrigation application, Plant transport, Plant handling, and Agrochemical application. Overall intent to adopt technologies within each cluster was neutral but slightly negative. Attitudes towards adopting automated nursery technologies and perceptions of others’ approval for adoption were positive, and perceived behavioral control and perceptions of others’ adoption were neutral. When used to predict likelihood of adoption through multiple linear regression models, there was variability in characteristics that predicted intent to adopt technologies within each cluster with attitude being the most consistent predictor across the clusters. There were both positive and negative relationships between the social norms variables and behavioral intent. Overall, social norms and attitudes appear to be among the most important characteristics in disseminating automated nursery technology adoption to address labor issues

Indole-3-butyric acid accelerates adventitious root formation and impedes shoot growth of Pinus elliottii var. elliottii × P. caribaea var. hondurensis cuttings

Many plantation tree species are cloned to achieve the growth, disease resistance and wood quality characteristics required for a successful economic venture. However, clonal propagation is limited by declines in adventitious root formation with increasing stock plant age. We examined the effects of immediate or delayed IBA application on adventitious root formation and subsequent root and shoot development of cuttings harvested from 8-year-old clonal hedge plants of Pinus elliottii var. elliottii × P. caribaea var. hondurensis. IBA applied at the time of setting accelerated root formation, elevating the percentage of cuttings with roots at 13 weeks post-setting from 45 to 78% and from 83 to 93% for a low- and a high-rooting clone, respectively. Final rooting percentages for the same treatments and clones (78 and 85%, and 88 and 100%, respectively, at 20 weeks post-setting) were not significantly affected by IBA application. IBA increased the root:shoot ratio of rooted cuttings by decreasing shoot weight compared with untreated cuttings, without affecting root weight, root length, root surface area or root volume. IBA was only effective when applied at the time of setting. A simple IBA treatment for cuttings from 8-year-old clonal hedges, by accelerating root production, has potential for reducing nursery costs and increasing the root system quality of containerised pine cuttings. © 2010 Springer Science+Business Media B.V