A study was initiated at the Southwest Purdue Ag Center to demonstrate the effect of transplant age and transplanting date on the scheduling of melon harvests. Muskmelon (Cucumis melo cv. Superstar) was seeded into #38 growing trays with Jiffy-mix media. Seeding dates were such that 14 and 21 day old seedlings were transplanted April 25, May 9, 17 and 24. The plants were grown on black plastic with trickle irrigation Marketable fruit were harvested starting on June 28 and continuing through August 12. Neither transplant age or date had a significant effect on the number of fruit harvested or on total yield. However, each transplant date showed a distinctive harvest peak beginning June 30 for the April 26 transplant then June 7, 14 and 21 for each successive transplant date.
James E. Simon, W. Dennis Scott, and Gerald Wilcox
Renee G. Nation, Jules Janick, and James E. Simon
The rate of outcrossing in basil [eight accessions of Ocimum basilicum L. and one accession purported to be O. kilimandscharicum Guerke (`Juicy Fruit')] was estimated using a purple seedling marker in `Dark Opal' (O. basilicum). There were two patterns of outcrossing: `Picollo' and four sources of `Cinnamon' basil had outcrossing rates between 19.9% and 32.8%, while `Lemon', PI 368699, PI 174284, and a Purdue selection named `Juicy Fruit' had outcrossing rates between 1.6% and 3.4%.
Ernst Cebert, Denys J. Charles, and James E. Simon
Artemisia annua L. is an aromatic and medicinal plant of importance for its volatile essential oils, and the non-volatile artemisinin used in the treatment of malaria. To determine the optimum time of planting for growth and the accumulation of essential oils, seedlings of A. annua (Purdue accession 012) were transplanted into the field in Central Indiana in a RBD with 3 replications on April 25, May 24, June 24, and July 25, 1988. Plant samples were harvested every 2 weeks until first frost.
The April and May transplanting dates produced the tallest plants (>180 cm) while the May transplants accumulated the greatest fresh and dry weights. The average increase in plant height was greatest for the June 24 planting date at 9.8 cm per week. Regardless of planting date, all plants began to flower by early August and growth rate began to decrease by late August. Accumulation of essential oil (as rel. % dry wt.) was similar for all planting dates. Essential oil increased until floral initiation, then decreased for 2 weeks after which there was a rapid increase in oil accumulation. Maximum oil accumulation from all planting dates was reached on Sept. 28 after which growth continued to increase.
Ramu Govindasamy, Venkata S. Puduri, and James E. Simon
The purpose of this study was to predict Latinos', consumers from Mexico and Puerto Rico, willingness to buy ethnic produce recently introduced or new to market. Specifically, we analyzed and compared socioeconomic characteristics of 542 Mexican and Puerto Rican consumers and expressed value judgments on their willingness to buy ethnic produce that has been recently introduced or new to market. This study was based on a primary data set collected from interviewing 542 Latino consumers (Mexico and Puerto Rico origin). A bilingual questionnaire was prepared in Spanish and English for Mexicans and Puerto Ricans in 16 states (Connecticut, Delaware, Florida, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Vermont, and Virginia) and Washington, DC. Attributes that contributed toward willingness to buy new ethnic produce include respondent's expenditure on total produce and ethnic produce, perceptions such as the importance of store availability, language, willingness to buy locally grown, organic, genetically modified, and country of origin labeled produce items. This information will assist market intermediaries and farmers better understand Latino consumers' (Mexico and Puerto Rico group) perceptions and factors that drive willingness to buy ethnic produce that is recently introduced or new to market.
Liangli Yu, Denys J. Charles, Jules Janick, and James E. Simon
The aroma volatiles of ripe fresh `GoldRush' and `Golden Delicious' apples (Malus ×domestica Borkh) were examined using dynamic headspace to capture the volatiles and gas chromatography (GC)–GC–mass spectroscopy (MS) analysis for compound identification. A total of 21 aroma volatiles were identified, with 16 being common to both cultivars: toluene, butyl acetate, hexyl formate, 2-methylbutyl acetate, xylene, butyl propionate, pentyl acetate, s-butyl butanoate, hexyl acetate, iso-butyl 2-methylbutanoate, hexyl propionate, hexyl butanoate, hexyl 2-methylbutanoate, hexyl hexanoate, a-farnesene, and ethyl phthalate. Three volatiles [dipropyl disulfide, pentyl 2-methylpropionate, and 2,6-bis(1,1-dimethylethyl)-2,5-cyclohexadiene-1,4-dione] were unique to `Golden Delicious'; two compounds (nonanal and nerolidol) were unique to `GoldRush'. Most identified compounds were esters. Hexyl acetate (18.39%) was the major volatile in `Golden Delicious', while butyl acetate (13.40%) was the highest in `GoldRush'.
Liangli Yu, Denys J. Charles, Amots Hetzroni, and James E. Simon
The volatiles of muskmelon (Cucumis melo L. reticulatis cv. Mission) were sampled by dichloromethane extraction and dynamic headspace methods and analyzed by gas chromatography (GC) and GC–mass spectroscopy (MS). A total of 34 constituents were identified, with esters contributing 8%–92% of the total volatiles. Butyl propionate, ethyl 3-methylpentanoate, hexadecanoic acid, methyl (methylthio)acetate, propyl butyrate, phenylpropyl alcohol, and vanillin, were recovered only by solvent extraction, while hexanal was only detected using dynamic headspace sampling. Methyl butyrate 35.2%, ethyl acetate 17.1%, butyl acetate 11.6%, ethyl propionate 8.3%, and 3-methylbutyl acetate 6.3% were the major constituents by solvent extraction sampling method. Butyl acetate 35.5%, 3-methylbutyl acetate 20.9%, ethyl acetate 7.3%, 2-butyl acetate 5.6%, and hexyl acetate 3.8% were the major constituents recovered by headspace sampling. Fruit tissue was also separated into five layers (exocarp, outer mesocarp, middle mesocarp, inner mesocarp, and seed cavity) and the volatile constituents differed significantly in content and composition by tissue.
Ali O. Sari, Mario R. Morales, and James E. Simon
Echinacea pallida, one of the three medicinal Echinacea species native to North America, is generally wildcrafted, and low and uneven seed germination are obstacles to its widespread cultivation. Nonstratified E. pallida seeds were treated with 2500, 3500, and 4500 mg/L GA3 to increase seed germination. Treated seeds were directly germinated at 25 °C and 25/15 °C (14/10h) or stored at 5 and 10 °C for 4, 8, and 12 weeks before germination at the same temperatures. Seed germination across treatments was higher at 25 °C (19%) than at 25/15 °C (14%). Application of 2500, 3500, and 4500 mg/L GA3 significantly increased seed germination rate and total seed germination of nonstratified seeds of E. pallida and resulted in 44%, 50%, and 63% total seed germination, respectively, while untreated control seeds germinated at only 9%. The effect of GA3 as a germination stimulant increased with cold storage, with maximum germination (83%) occurring after seeds were treated with 4500 mg/L GA3 and an 8-week cold storage period at 10 °C. The effect of cold storage periods of 4, 8, and 12 weeks and cold storage temperatures of 5 and 10 °C on seed germination were generally similar. Seeds collected from the upper rows of the seed heads germinated significantly higher (10.6%) than those collected from the lowest seed rows (2.4%).
Roberto F. Vieira, Peter Goldsbrough, and James E. Simon
Molecular markers were used to assess genetic diversity in basil (Ocimum L. spp., Lamiaceae). Using randomly amplified polymorphic DNA (RAPD) analysis, 11 primers generated 98 polymorphic bands, ranging from 300 to 2,000 base pairs, that discriminated among 37 accessions across nine Ocimum spp. Means of genetic similarities within Ocimum spp. showed that the domesticated species, O. minimum L. (0.887), O. basilicum L. (0.769), and O. ×citriodorum Vis. (0.711) had highest similarity indices within species, while the nondomesticated, O. americanum L. (0.580), O. gratissimum L. (0.408), and O. kilimandscharicum Guerke (0.559) showed the lowest similarity. RAPD results indicated that O. minimum should not be considered a distinct species but rather a variety of O. basilicum. Consistent clusters among all but one of the O. ×citriodorum spp., all containing citral as the major constituent, were identified using bootstrap analysis. RAPD analysis was useful in discriminating among Ocimum spp., although within species resolution will require a higher number of polymorphic bands.
Gwendolyn Eason, Richard A. Reinert, and James E. Simon
Three watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] cultivars with different ozone (O3) sensitivities were grown in a charcoal-filtered greenhouse and exposed in continuous-stirred tank reactor chambers to five levels (0, 100, 200, 300, or 400 nL·L-1) of sulfur dioxide (SO2) in the presence (80 nL·L-1) or absence (0 nL·L-1) of ozone (O3) for 4 hours/day, 5 days/week for 22 days. In the presence of O3, SO2 increased foliar injury in all three cultivars, but the impact was greatest for the most O3-sensitive cultivar, `Sugar Baby,' moderate for `Crimson Sweet,' and least for the least O3-sensitive cultivar, `Charleston Gray.' For all cultivars, SO2 intensified O3 suppression of leaf area for the first seven mainstem leaves and of dry weights for aboveground and total plant tissues. Root dry weight was independently suppressed by both pollutants, and the root: top ratio was linearly suppressed by SO2 alone. Sulfur dioxide combined with O3 can be detrimental to crop species such as watermelon. Thus, the potential for SO2 phytotoxicity should not be summarily dismissed, especially in the vicinity of SO2 point sources where O3 co-occurs.
Jorge F.S. Ferreira, James E. Simon, and Jules Janick
Artemisinin (qinghaosu), an endoperoxide sesquiterpene lactone with antimalarial activity and little human toxicity, is produced in A. annua L., a short-day plant with the critical photoperiod of 13.5 h. Artemisinin peaks at full flowering when it is 11 times higher in inflorescences than in leaves. Supplementation of MS medium with BA, kinetin, CCC, or daminozide decreased content in shoot cultures as compared to the control, with the exception of CCC at 6.3 μM. Artemisinin content (percent dry weight) in this experiment did not correlate with shoot number (r = –0.198) but was highly correlated (r = 0.775**) with root number, indicating that although roots do not produce artemisinin, they may be involved in its synthesis. Maximum artemisinin was produced in hormone-free medium. Friable calli were obtained with a combination of BA (4.4 μM) and 2,4-D (4.5 μM), but artemisinin was absent from calli, cells, and cell culture media. Biseriate glandular trichomes are present in leaves and flowers from the earliest developmental stages. Artemisinin was extracted by a 1-min dip in organic solvents from flowers and leaves, indicating that the biseriate glandular trichomes of A. annua are the probable site of accumulation or sequestration of artemisinin.