William J. Sciarappa

Fruit Quality, Antioxidant Capacity, and Flavonoid Content of Organically and Conventionally Grown Blueberries

The effect of cultivation practices on fruit quality and antioxidant capacity in highbush blueberries var. Bluecrop (Vaccinium corymbosum L.) was evaluated from random samples of commercial late harvest fields in New Jersey. Results from this study showed that blueberry fruit grown from organic culture yielded significantly higher sugars (fructose and glucose), malic acid, total phenolics, total anthocyanins, and antioxidant activity (ORAC) than fruit from the conventional culture. In organically cultured fruit, the average values for the ORAC, total anthocyanins, and total phenolic content were 46.14 micromol of Trolox (TE)/g of fresh weight (fwt), 131.2 mg/100 g of fwt, and 319.3 mg/100 g of fwt, respectively. In conventionally cultured fruit, the average values for the ORAC, total anthocyanin, and total phenol content were 30.8 micromol of TE/g of fwt, 82.4 mg/100 g of fwt, and 190.3 mg/100 g of fwt, respectively. The organic culture also produced fruit with higher contents of myricetin 3-arabinoside, quercetin 3-glucoside, delphinidin 3-galactoside, delphinidin 3-glucoside, delphinidin 3-arabinoside, petunidin 3-galactoside, petunidin 3-glucoside, and malvidin 3-arabinoside than conventional culture. There was a significant correlation between the ORAC values and total phenolics and total anthocyanins. These results indicate that even though there were variations in phytonutrient content among individual farms within each cultural system, significant differences between two cultivation practices were evident.

Comparative Effectiveness of Different Insecticides for Organic Management of Blueberry Maggot (Diptera: Tephritidae)

Abstract Laboratory and field assays using insecticides for organic pest management were conducted on the blueberry maggot, Rhagoletis mendax Curran. Topical exposure of flies to spinosad (Entrust), pyrethrum (PyGanic 1.4 EC), azadirachtin (Aza-Direct), and phosmet (Imidan 70-W) resulted in significantly higher mortality compared with the water control after 2 and 24 h. After 24 h, there were no significant differences in fly mortality among treatments of Entrust, PyGanic, or Imidan, whereas fly mortality to Aza-Direct was significantly lower. Another laboratory assay evaluated mortality of flies after residual exposure to these insecticides on leaves, after 24 and 48 h. In this assay, there were no significant differences in fly mortality after 48 h among treatments of PyGanic, Aza-Direct, and the water control, whereas significantly higher fly mortality resulted from exposure to Entrust and Imidan. A repellency assay found no measurable effects of Aza-Direct. Large-scale field trials found no treatment effect for number of adults of the blueberry maggot captured in sticky traps; however, there were significantly lower levels of fruit-infesting larvae in treated plots compared with the untreated control. Spinosad bait (GF-120 NF Naturalyte Fruit Fly Bait), Entrust, and PyGanic were not different from imidacloprid (Provado 1.6 F). However, there was a significantly higher infestation in the plot treated with azadirachtin (Agroneem) compared with Provado. Overall, the insecticides evaluated in these trials showed good ability to control blueberry maggot, suggesting that they can be incorporated in a blueberry maggot management program under organic standards.

Disruption of Sexual Communication of Oriental Beetles (Coleoptera: Scarabaeidae) in Highbush Blueberries with Retrievable Pheromone Sources

Abstract The feasibility of disrupting sexual communication in oriental beetle, Anomala orientalis (Waterhouse), was evaluated by placing 50–75 ChemTica dispensers/ha (50–75 g active ingredient/ha) that released (Z)-7-tetradecen-2-one, the major sex pheromone component of oriental beetle, or red rubber septa deployed at the same density, but loaded with only 5–7.5 g active ingredient/ha, in 2002 and 2003. In both years, pheromone trap captures in plots treated with dispensers and rubber septa were significantly lower compared with pheromone trap captures in untreated control plots. Significantly fewer grubs were found in 2002 in blueberry plants placed in the two disrupter treatments compared with untreated control plots. In 2003, fewer females recovered from disrupter plots were found mated compared with females placed in untreated control plot. These studies indicate that sexual communication in the oriental beetle can be disrupted by deploying retrievable dispensers releasing high rates of pheromone at lower densities than previously thought.

Comparing Conventional, Hybrid, and Distance Learning Courses in Horticulture

In a conventional sophomore level course entitled ‘‘Organic Farming and Gardening,’’ 114 undergraduate students registered from years 2007 to 2009. Due to high demand and insufficient classroom space, this conventional curriculum was reformattedwith identical course content into both a hybrid and a fully online version in which 361 students registered from years 2010 to 2012 and 336 students from 2013 to 2015. In comparing conventional instruction with hybrid and fully online versions over a 9-year period, few significant differences were found in final grades involving 811 students. Final class grade averages of these three learning systems ranged from 85.5% to 89.6% over their first 3-year spans. Over their 6-year span, the conventional class average of 89.6% was higher compared with 88.3% for the hybrid format and 86.8% for the online format. Student evaluation surveys assessed faculty performancewith eight evaluative questions on a 1 to 5 scale from years 2012 to 2014. No significant difference existed between teaching in person vs. remotely, averaging 4.35 for the hybrid and 4.17 for the online. An additional eight questions measured educational methodology, technology, student confidence, and class satisfaction. There were no significant differences in comparing the combined averages of 4.12 for the hybrid format and 4.00 for the online version. Student responses indicated a significant preference overall for hybrid and online course formats compared with conventional methods. Registration numbers indicated an overwhelming choice for online education with an average class enrollment of 91.0 students compared with 38.0 students for conventional classes and 25.2 students for the hybrid format.