Our objective was to develop a rapid technique for the non-invasive profiling and quantification of major tomato carotenoids using handheld Raman spectroscopy combined with pattern recognition techniques. A total of 106 samples with varying carotenoid profiles were provided by the Ohio State University Tomato Breeding and Genetics program and Lipman Family Farms (Naples, FL, USA). Non-destructive measurement from the surface of tomatoes was performed by a handheld Raman spectrometer equipped with a 1064 nm excitation laser, and data analysis was performed using soft independent modelling of class analogy (SIMCA)), artificial neural network (ANN), and partial least squares regression (PLSR) for classification and quantification purposes. High-performance liquid chromatography (HPLC) and UV/visible spectrophotometry were used for profiling and quantification of major carotenoids. Seven groups were identified based on their carotenoid profile, and supervised classification by SIMCA and ANN clustered samples with 93% and 100% accuracy based on a validation test data, respectively. All-trans-lycopene and β-carotene levels were measured with a UV-visible spectrophotometer, and prediction models were developed using PLSR and ANN. Regression models developed with Raman spectra provided excellent prediction performance by ANN (rpre = 0.9, SEP = 1.1 mg/100 g) and PLSR (rpre = 0.87, SEP = 2.4 mg/100 g) for non-invasive determination of all-trans-lycopene in fruits. Although the number of samples were limited for β-carotene quantification, PLSR modeling showed promising results (rcv = 0.99, SECV = 0.28 mg/100 g). Non-destructive evaluation of tomato carotenoids can be useful for tomato breeders as a simple and rapid tool for developing new varieties with novel profiles and for separating orange varieties with distinct carotenoids (high in β-carotene and high in cis-lycopene).

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Pepper weevil is the major pest of all pepper varieties in the southern parts of the US, due in part to the inaccessibility of all but the adult stage to insecticide sprays. Best results have been achieved with rotations of products such as were evaluated in this experiment. Greenhouse-raised pepper plants were transplanted on 22 Mar at 10-inch spacing in single rows on two sets of three beds 250 ft in length and covered with polyethylene film mulch. Approximately 20% of the fertilizer was preplant soil incorporated and 80% applied through the drip tape. The center bed in each set of three was left untreated to serve as a source of weevils. Each treated-bed was divided into plots 42 ft long to which treatments were assigned in a RCB design with four replications. A high-clearance sprayer was used operating at 180 psi and 2.3 mph with the spray delivered through two vertical booms using yellow Albuz hollow cone nozzles that applied 10 gpa each. The first three applications were applied with two nozzles on each boom applying a total of 40 gpa, and then increased to three nozzles applying 60 gpa on subsequent applications as the plants grew taller (Table 1). As the number of gpa was increased to maintain spray coverage on the taller plants, the rate per acre was kept constant.

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