or higher ( Santos and Gilreath, 2005 ). Furfural, a natural byproduct of sugarcane ( Saccharum officinarum ) processing, is another molecule proposed by Rodriguez-Kabana (2005) as an effective MBr alternative to control nematodes in greenhouse
James P. Gilreath, Bielinski M. Santos, and Timothy N. Motis
James S. Gerik
Field trials were conducted to test fumigants as alternatives to methyl bromide (MB) for production of hybrid freesia (Freesia × hybrida). One trial compared rates of 1,3-dichloropropene (DP) combined with chloropicrin (CP); the second trial compared iodomethane (IM) together with CP, DP:CP, and furfural with and without metham sodium; and the third trial compared rates and formulations of IM:CP to the standard MB:CP treatments. Most treatments reduced populations of Pythium spp. and controlled weeds compared to the untreated controls. Formulations of IM:CP reduced the incidence of disease caused by Fusarium oxysporum. Treatments of IM:CP performed as well as MB:CP, and treatments of DP:CP performed as well as IM:CP. Presently only the DP, CP and metham sodium formulations are registered for use on ornamental crops. Registration of the IM formulations will improve the options available to cut flower growers for management of plant pathogens and weeds.
James S. Gerik, Ian D. Greene, Peter Beckman, and Clyde L. Elmore
Two field trials were conducted from 2002 until 2004 to evaluate several chemicals as alternatives to methyl bromide for the production of calla lily (Zantedeschia sp.) rhizomes. Various rates and chemical combinations were tested. The chemicals were applied through a drip irrigation system. The chemicals included iodomethane, chloropicrin, 1,3-dichloropropene, metham, sodium furfural, and sodium azide. None of the treatments reduced the viability of seed of mallow (Malva parviflora) previously buried in the plots. Propagules of nutsedge (Cyperus esculentus) and seed of mustard (Brassica nigra) were controlled by iodomethane + chloropicrin, 1,3-dichloropropene + chloropicrin, chloropicrin alone, 1,3-dichloropropene alone, and furfural + metham sodium. Propagules of calla were controlled by all of the treatments except sodium azide and furfural + metham sodium. In the first trial, all treatments reduced the populations of soilborne plant pathogens, including Pythium spp., Phytophthora spp., and Fusarium oxysporum, except for sodium, which did not reduce the population of Phytophthora spp. In the second trial, all treatments controlled Pythium spp. but only a high rate of iodomethane + chloropicrin reduced the population of F. oxysporum. For all treatments, the incidence of disease caused by soilborne pathogens was reduced compared to the nontreated control. The number and value of harvested rhizomes were greater among all of the treatments, except for sodium azide, compared to the control. The harvested value of the crop for the best treatments increased significantly compared to the control. A successful crop of calla rhizomes can be produced by combinations of iodomethane, chloropicrin, 1,3-dichloropropene, and metham sodium.
Jyh-Bin Sun, Ray F. Severson, and Stanley J. Kays
We describe a relatively simple collection procedure for quantifying volatiles in baked sweetpotato [Ipomoea batatas (L.) Lam.]. Volatiles formed during baking `Jewel' and `Centennial' sweetpotatoes at 204C were purged from a baking vessel with He or a HeO2 mixture, collected in cold methylene chloride, and reduced in volume using a Kuderna-Danish concentrator. Volatile components were quantified by capillary gas chromatography and characterized using gas chromatographic-mass spectrometer analysis. Quantitatively, the major components were identified as 2-furaldehyde; 2-furanmethanol; benzaldehyde; 5-methyl-2-furfural; phenylacetaldehyde; 3-hydroxy-2-methyl-4 H -pyran-4-one; 2,3-dihydro-3,5-dihydroxy-6-methyl-4 H- pyran-4-one; and 5-hydroxy-methyl-2-furancarboxaldehyde. Some quantitatively minor compounds were also identified. The volatile collection system is reproducible for quantitative comparisons among breeding lines.
Yan Wang and Stanley J. Kays
Flavor quality is one of the most difficult traits to select in plant breeding programs due to the large number of sensory panelists required, the small number of samples that can be evaluated per day, and the subjectivity of the results. Using sweetpotato [Ipomoea batatas (L.) Lam.] as a model, clones exhibiting distinctly different flavors were analyzed for sugars, nonvolatile acids, and aroma chemistry to identify the critical flavor components. Differences in sugars, sucrose equivalents, nonvolatile acids, and 19 odor-active compounds were identified that accounted for differences in flavor among the clones. Using the intensity of the aroma per microliter for each of the 17 most important aroma-active compounds (maltol, 5-methyl-2-furfural, 2-acetyl furan, 3-furaldehyde, 2-furmethanol, benzaldehyde, phenylacetaldehyde, β-ionone, 1,2,4-trimethyl benzene, 2-pentyl furan, 2,4-decadienal, 2,4-nonadienal, linalool, geraniol, cyperene, α-copane and a sesquiterpene) and the relative sweetness of individual sugars × their respective concentrations, multivariate (principal component and cluster) analysis allowed accurate classification of the clones according to flavor type without sensory analysis. The level of precision was such that sweetness, starch hydrolysis potential, and the concentration of β-carotene could be accurately predicted by quantifying specific volatiles. Analytical assessment of flavor would greatly facilitate the accurate evaluation of large numbers of progeny, the simultaneous selection of multiple flavor types, and the development of superior new cultivars for a wide cross-section of food crops.
Yan Wang and S.J. Kays
Breeding sweetpotatoes [Ipomoea batatas (L.) Lam.] for improved flavor would be greatly facilitated by understanding the flavor chemistry of the crop. To ascertain the chemical composition of the aroma, an aroma extract of baked `Jewel' sweetpotatoes was obtained using a cold solvent trap system and analyzed by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and gas chromatography olfactometry (GCO) using aroma extract dilution analysis (AEDA). GC with a flame ionization detector (GC-FID) revealed ≈60 compounds presented in the aroma extract, of which 48 were identified. Olfactory evaluation of the eluted compounds using GC with a thermal conductivity detector (GC-TCD) indicated the presence of 37 odor-active peaks in the aroma extract. Three compounds, phenylacetaldehyde (perfume), maltol (caramel), and methyl geranate (2,6-octadienoic acid, 3,7-dimethyl-, methyl ester) (sweet candy) possessed the highest flavor dilution (FD) values (1500) via AEDA. 2-Acetyl furan (baked potato), 2-pentyl furan (floral), 2-acetyl pyrrole (sweet, caramel), geraniol (sweet floral), and β-ionone (violet) had FD values of 1000. These compounds are thought to be the most potent odorants in baked `Jewel' sweetpotatoes. Additionally, 1,2,4-trimethyl benzene, 2-furmethanol, benzaldehyde, 5-methyl-2-furfural, linalool, isopulegone, n-decanal, 2,4-decadienal, octyl ketone, α-copaene, 4-decanolide, and one unidentified compound were also contributors to the aroma. There was not a character impact compound that comprised the basic baked sweetpotato aroma. The aroma appeared to be made up of a relatively complex mixture of compounds. Maillard and/or caramelization reactions, Strecker degradation of phenylalanine, lipid and carotenoid degradation, and the thermal release of glycosidically bound terpenes appear to be involved in the formation of the characteristic aroma of baked `Jewel' sweetpotatoes.
Inga A. Zasada, Thomas W. Walters, and John N. Pinkerton
relatively short half-life in soil ( Oka et al., 2008a ). Another grouping of nematicides includes plant-based products, including furfural (2-furancarboxaldehyde), saponins of soapbark, and extracts of walnut ( Juglans regia ). Furfural is a liquid found in
Raymond A. Cloyd, Karen A. Marley, Richard A. Larson, and Bari Arieli
the dicarboxylic acids, C4-C5 as well as furfural and 5-methylfurfural. Cyclosulfur (S8) was present in each of the commercially mixed growing media, but not in the rice hull material. The rice hull material contained nearly 10 times as much C16 (39
Sally M. Schneider, Husein A. Ajwa, Thomas J. Trout, and Suduan Gao
properties of drench applications of furfural (2-fururaldehyde) 19 1 Proc. Annu. Intl. Res. Conf. on Methyl Bromide Alternatives and Emissions Reductions, 31 Oct.–3 Nov. 2005, San Diego, CA 15 July 2008 < http://www.mbao.org/2005/05Proceedings
Feras Almasri, Husein A. Ajwa, Sanjai J. Parikh, and Kassim Al-Khatib
Furfural-based biofumigant mixtures for control of phytopathogenic nematodes and weeds, p. 395. In: Proceedings of International Conference on Alternatives to Methyl Bromide. < https://pdfs.semanticscholar.org/e50b/4b1fe9195eaabfe4fd8d3a75061f9edaa3a9.pdf