Inhibition of flower bud development increased with the concn of naphthenic or paraffinic oil. In some cases, additions of 1 or 2% succinic acid 2,2-dimethylhydrazide (SADH) in oil sprays reduced bud injury and resulted in more flowering terminals and fruit set than oil sprays alone. A January 1969 spray of 50% naphthenic oil with 1% SADH appeared to delay bud activity and prevent freeze injury to the flower buds in early February. Trees that were sprayed with 50% naphthenic oil and 1% SADH on February 18, 1971, withstood a freeze on March 5 and produced a partial fruit crop.
Oil yield of peppermint (Mentha piperita L.) per unit area obtained from plant density treatments 30 and 40 plants/m2, reached a maximum early in the growing season, whereas oil yield from the lower density treatment, 10 plants/m2, continued to increase even at a menthol content of 50%. The latter density treatment yielded less oil per unit area. At the 2 highest densities, herb harvested at a stage when oil contained 45% free menthol resulted in maximum oil yield and optimum oil quality. Delaying harvest once the above stage had been reached resulted in increased levels of menthol but at the expense of increased levels of menthofuran and decreased oil yields. As the growing season progressed, menthol and menthyl acetate contents of oil increased while menthone decreased. This effect was accelerated at the high plant densities.
Arsenic (As) and lead (Pb) sprays applied to grapefruit (Citrus paradisi Macfad.) accelerate fruit maturity but do not contribute to the As and Pb content of the peel oil. The physicochemical properties of the expressed oils are influenced by this induced maturity but would occur naturally in the course of normal fruit maturation.
Effects of different plant oils (soybean, corn, peanut, cottonseed, conola, sunflower, safflower, rape seed, and linseed) on mealiness, leatheriness, and flesh browning (FB) in `Elegant Lady' peaches (Prunus persica Batsch) were studied. Fruit were harvested at three dates (10 days apart) with the second harvest concomitant to commercial harvest, dipped in a 5% or 10% oil emulsion for 3 min, and stored at 0 or 5 °C, respectively. After 6 weeks at 0 °C, fruit developed more leatheriness and FB but less mealiness in early harvested compared to late-harvested fruit. When stored at 5 °C, fruit did not develop any leatheriness regardless of harvest dates, but fruit from the last harvest developed high levels of mealiness and FB compare with fruit from the other two harvests. FB was found only, but not in all, leathery or mealy fruit. None of the oils affected leatheriness, but all reduced mealiness to the same extent at the same concentration. Oil treatments controlled FB completely in both leathery and mealy fruit. Oil at 10 % was more effective in controlling mealiness and FB than at 5%. Oil-treated fruit had higher flesh firmness and titratable acidity and developed less decay than the controls at removal from storage.
Seed of California almond [Prunus dulcis (Mill.) D.A. Webb, syn. P. amygdalus Batsch, and P. communis (L.) Arcangeli, non-Huds.] genotypes contained very low saturated fatty acids, high monounsaturated fatty acids, and low polyunsaturated fatty acids. Kernel oil consisted primarily of five fatty acids: palmetic, palmetoleic, stearic, oleic, and linoleic. Linolenic acid was only present in amounts of <0.02% and only in a few samples. Small but significant differences among genotypes and sampling sites were found in the proportions of palmetic, palmetoleic, and stearic fatty acids. The major differences in fatty acid composition among genotypes was found in the proportions of oleic, a monounsaturated fatty acid, and linoleic, a polyunsaturated fatty acid. The proportion of oleic acid was highest, ranging from ≈62% to 76%, and was highly and negatively correlated with linoleic acid levels. Usable genetic variation and a significant genotype × environment interaction were identified for oil content and composition. The introgression of new germplasm from peach and related species does not appear to reduce oil quantity or quality, and may offer opportunities for further genetic improvement of kernel oil composition.
The yield of inflorescences and essential oil of ‘Dutch’ lavandin (Lavandula x intermedia Emeric ex Loisel.) was increased significantly with the addition of a 2.5-cm topdressing of white sand. Fertilization did not increase yields on a near-optimally fertile soil.
Sweet basil (Ocimum basilicum L.) plants were grown, until flower buds became visible, in a peat-lite mix and watered daily with a complete nutrient solution with 10 mm N as either or . Ammonium decreased plant height and stem plus petiole dry weight. Leaf blade dry weight was not affected by N form. However, the essential oil content was decreased by 28% with , thereby decreasing the essential oil yield per plant. Although decreased the content (nl·g-1 leaf blade dry weight) of linalool and eugenol, their percentage was not altered. Therefore, the changes in total yield of these individual constituents was simply a reflection of less total extractable essential oil. The total amount of the other major constituents in sweet basil, 1,8-cineole, methyl chavicol, and total sesquiterpenes was not affected significantly. While N form did not alter the percentage of monoterpenes and aromatic polypropa-noides, -N increased the total sesquiterpene percentage. Nitrogen form altered the essential oil content and composition of sweet basil and, therefore, should be considered in nutritional studies with aromatic plants.
Vernonia galamensis is a potential new crop for production of epoxidized oil with many industrial applications. This plant is native to equatorial Africa, and not adapted for culture in temperate zones since it requires a short daylength to initiate flowering and subsequent seed development. One collection of V. galamensis ssp. galamensis var. petitiana, flowered freely and produced seeds during long-day conditions throughout the United States. This variety lacks important plant characters for successful commercialization. The favorable genetic recombination of day-neutral response with more desirable plant growth characteristics, desirable seed oil and fatty acid content from other accessions of V. galamensis has been accomplished in hybrids and segregating populations, and selections are being widely evaluated throughout the U.S..
Leaves of three strawberry cultivars (Bounty', `Honeoye', and `Kent') were collected at random from plants growing in an experimental trial at the Agriculture Canada, Research Station farm at Lavaltrie, Quebec. Steam-distillation was carried out on 300g of leaves in 3L of distilled water in a 5L flask. The essential oils were analyscd with a Varian 6000 gas chromatogmph. Thirty-seven compounds were detected of which sixteen were identified. The major components were linalool and nonanal. Many of the other constituents were aliphatic in nature. Differences in oil composition among the three cultivars were observed. Essential oil composition might therefore be used as a selection criteria for insect or disease resistance. Their effect upon mites will be assayed in future studies by testing them as sex, food, or oviposition lures.
Preclimacteric `Bartlett' pears (Pyrus communis L.) were dipped for 3 min in either corn (Zea mays L.) or soybean [(Glycine max (L.) Merrill] oil emulsion immediately after harvest and stored at 0 °C. Untreated control fruit developed higher percentages of senescent scald, core breakdown, and decay after 15 weeks storage. Both treatments inhibited senescent scald, core breakdown, and decay in a similar and concentration dependent manner. Complete control of senescent scald and core breakdown was achieved by emulsions at 5% and 10%, and of decay by emulsion at 10%. Compared with controls, emulsion treatments delayed and reduced internal ethylene accumulation and volatile production in early storage and increased them in late storage. Compared with controls, fruit treated with oil contained similar levels of internal O2 and CO2 in early storage and higher CO2 and lower O2 in late storage. While control fruit lost commercial value after 15 weeks at 0 °C plus 5 days at 20 °C, oil-treated fruit exhibited normal color change, and had higher soluble solids, titratable acidity, and volatile production. Microscopic examination revealed that emulsion-treated fruit had a continuous surface film conforming to the contour of the fruit.