Fresh weight production of basil (Ocimum basilicum`Genovese') growing in a retractable roof greenhouse (RRGH) or outdoors was evaluated under different shade environments, cultural production systems, and roof control strategies in a semi-arid climate. Cultural production systems included raised beds and towers consisting of six pots arranged vertically and stacked on edge. The growing substrate in both systems was perlite. The three shade environments included a RRGH with either a clear woven roof (35% shade) or a white woven roof (50% shade), or outdoors in full sun (0% shade). Within the RRGH, three strategies of roof control were tested based on air temperature thresholds, quantum thresholds, and globe thermometer temperature thresholds. After establishment, plants were grown for 4 weeks, each under the three roof control strategies in each environment and in both cultural systems. New shoots were harvested weekly and fresh weights were determined. Overall, fresh weight per plant was significantly affected by cultural production system, and basil grown in raised beds produced twice the biomass compared to plants grown in vertical towers. Productivity of basil grown in raised beds was not affected by the three shade environments, but plants in vertical towers produced about 20% more when grown in full sun or under 35% shade compared to under 50% shade. Within the RRGH, roof control strategy significantly affected basil fresh weight per plant. Roof control, based on either a quantum sensor or globe thermometer, increased production by 31% compared to air temperature control. Greater productivity was related to higher cumulative light exposure of plants. Quality of basil grown in the RRGH was superior to that grown in full sun.
Jennifer Nelkin and Ursula Schuch
Joshua K. Craver and Kimberly A. Williams
Student learning from producing crops in recirculating culture for a 6-week module in the Fall 2013 course HORT 570 Greenhouse Operations Management at Kansas State University was assessed. The module design followed Kolb’s experiential learning model, with teams of students responsible for production of lettuce (Lactuca sativa ‘Green Oak Leaf’) or basil (Ocimum basilicum ‘Italian Large Leaf’) and chives (Allium schoenoprasum ‘Purly’) crops in either a nutrient film technique (NFT) or in-pot recirculating culture system. Goals were to discern if this class experience would 1) improve student confidence and understanding of not only recirculating solution culture systems, but also general crop nutrient management; and 2) improve higher-order learning (HOL) skills of applying, analyzing, and evaluating information. Student learning was evaluated by administering the same survey, which included questions to evaluate student perception, lower-order learning (LOL), and HOL, at four separate times during the semester: 1) before mentioning plant nutrition, hydroponics, or recirculating solution culture; 2) after plant nutrition lectures but before the experiential module; 3) immediately upon completion of the experiential module; and 4) at the end of the semester. An increase in student confidence related to managing crop production in recirculating solution culture and nutrient management was perceived by students upon completion of the module. A significant increase in LOL occurred after the material was presented during the course lectures with an increase also occurring upon completion of the experiential module. In contrast, HOL did not significantly increase after the lecture material was presented, but significantly increased upon completion of the module. Both LOL and HOL was retained at the end of the semester. This evidence supports the role of experiential learning in improving student understanding and fostering HOL.
Dean A. Kopsell, Carl E. Sams, T. Casey Barickman, Dennis E. Deyton, and David E. Kopsell
Selenium (Se) is an essential mammalian micronutrient. Adult humans have a daily requirement of 55 to 70 μg/day Se depending on sex and pregnancy/lactation for females. In addition, recent studies have shown health benefits with dietary Se supplementation of 100 to 200 μg/day Se. However, daily intakes in humans greater than 900 μg Se will result in toxicity called selenosis. Although not essential in plant nutrition, some species can bioaccumulate Se. Brassica and Allium species became prime candidates for Se enrichment because of their ability to accumulate and tolerate high concentrations of Se in edible tissues; however, there is now concern that these species are too efficient at selenization and overconsumption of their selenized tissues could result in selenosis. Herbal crop species are consumed regularly in the diet for their culinary flavor attributes. Basil (Ocimum basilicum L.) and cilantro (Coridandrum sativum L.) are not classified as Se accumulators. Therefore, a study was undertaken to determine the potential to selenize basil and cilantro through foliar Se applications to consistently supplement diets with nutritionally beneficial levels of Se. Plants of each species were grown in both growth chamber and field environments and treated with foliar applications (5 mL per plant) of selenate-Se and selenite-Se at concentrations of 0, 2, 4, 8, 16, and 32 mg·L−1 Se. Crops received three separate foliar applications at ≈5-day intervals beginning 24 to 28 days after planting for the growth chamber plants and 50 days after planning for the field environment. Selenium accumulation in both basil and cilantro leaf tissues increased linearly under both selenate-Se (P ≤ 0.001) and selenite-Se (P ≤ 0.001) foliar treatments in growth chamber and field evaluations. Maximum Se leaf tissue concentrations for basil and cilantro ranged from 13 to 55 μg·g−1 Se dry weight. Selenization of basil and cilantro is possible through foliar Se applications, and Se fortification of herbal crops may provide alternative delivery systems in human diets.
Erin M.R. Clark, John M. Dole, Alicain S. Carlson, Erin P. Moody, Ingram F. McCall, Frankie L. Fanelli, and William C. Fonteno
Each year a wide variety of new cultivars and species are evaluated in the National Cut Flower Trial Programs administered by North Carolina State University and the Association of Specialty Cut Flower Growers. Stems of promising and productive cultivars from the National Trial Program were pretreated with either a commercial hydrating solution or deionized (DI) water and placed in either a commercial holding solution or DI water. Over 8 years, the vase life of 121 cultivars representing 47 cut flower genera was determined. Although there was cultivar variation within each genus, patterns of postharvest responses have emerged. The largest category, with 53 cultivars, was one in which a holding preservative increased vase life of the following genera and species: acidanthera (Gladiolus murielae), basil (Ocimum basilicum), bee balm (Monarda hybrid), black-eyed susan (Rudbeckia hybrids), campanula (Campanula species), celosia (Celosia argentea), common ninebark (Physocarpus opulifolius), coneflower (Echinacea purpurea), coral bells (Heuchera hybrids), feverfew (Tanacetum parthenium), foxglove (Digitalis purpurea), ladybells (Adenophora hybrid), lisianthus (Eustoma grandiflorum), lobelia (Lobelia hybrids), obedient plant (Physostegia virginiana), ornamental pepper (Capsicum annuum), pincushion flower (Scabiosa atropurpurea), pinkflower (Indigofera amblyantha), seven-sons flower (Heptacodium miconioides), shasta daisy (Leucanthemum superbum), sunflower (Helianthus annuus), snapdragon (Antirrhinum majus), sweet william (Dianthus hybrids), trachelium (Trachelium caeruleum), and zinnia (Zinnia elegans). Hydrating preservatives increased the vase life of four basils, coral bells, and sunflower cultivars. The combined use of hydrator and holding preservatives increased the vase life of three black-eyed susan, seven-sons flower, and sunflower cultivars. Holding preservatives reduced the vase life of 14 cultivars of the following genera and species: ageratum (Ageratum houstonianum), false queen anne's lace (Ammi species), knotweed (Persicaria hybrid), lisianthus, pineapple lily (Eucomis comosa), sneezeweed (Helenium autumnale), yarrow (Achillea millifolium), and zinnia. Hydrating preservatives reduced the vase life of 18 cultivars of the following genera and species: feverfew, lisianthus, ornamental pepper, pineapple lily, seven-sons flower, shasta daisy, sneezeweed, sweet william, sunflower, trachelium, yarrow, and zinnia. The combined use of hydrating and holding preservatives reduced the vase life of 12 cultivars in the following genera and species: false queen anne's lace, feverfew, pincushion flower, sneezeweed, sunflower, trachelium, yarrow, and zinnia. Data for the remaining 50 cultivars were not significant among the treatments; these genera and species included beautyberry (Callicarpa americana), black-eyed susan, blue mist (Caryopteris clandonensis), calendula (Calendula officinalis), campanula, cleome (Cleome hasserliana), common ninebark, dahlia (Dahlia hybrids), delphinium (Delphinium hybrids), flowering peach (Prunus persica forma versicolor), heliopsis (Heliopsis helianthoides), hemp agrimony (Eupatorium cannabinum), himalayan honeysuckle (Leycesteria formosa), hydrangea (Hydrangea paniculata), larkspur (Consolida hybrids), lily of the nile (Agapanthus hybrid), lisianthus, lobelia, ornamental pepper, pineapple lily, scented geranium (Pelargonium hybrid), sunflower, sweet william, and zinnia.
Eric B. Brennan
Many important herbs [e.g., mint (Mentha sp.), thyme (Thymus sp.)], underused and nutritious vegetables [e.g., purslane (Portulaca oleracea), amaranth (Amaranthus tricolor)], and important biological control plants [e.g., sweet alyssum (Lobularia maritima)] have small seeds (≤ 1.5-mm long) that are difficult to plant with raw (i.e., nonpelleted) seed using existing seeders. A novel tool known as the slide hammer (SH) seeder was developed for the precise seeding of raw seeds of small-seeded plants. The SH seeder is a jab-type planter made primarily from electrical conduit tubing and other materials that are inexpensive and readily available in a hardware store or on the Internet. The interchangeable seed hopper is made from a plastic snap cap vial that has one or more holes of varying diameter depending on the desired seeding rate and seed size. Seed forms a “bridge” above the hole in the vial until they are dislodged from the force of the SH that discharges seeds to fall to the soil. Detailed plans are provided for how to make and use the SH seeder. The fabrication time is 2 to 4 hours with a material cost of ≈$32. I determined the seed vial hole specifications for the precise seeding of a variety of small-seeded plants, including chives (Allium schoenoprasum), chinese chives (Allium tuberosum), basil (Ocimum basilicum), grain amaranth (Amaranthus sp.), sweet alyssum, purslane, creeping thyme (Thymus serpyllum), and spearmint (Mentha spicata) that ranged in size from ≈200 to 11,000 seeds per gram. The diameter of the hole that was suitable for discharging the seed from the vial was always larger than the average seed length, and the ratio of hole diameter to seed length ranged from 1.07 to 1.62. Seeding rate uniformity evaluations were conducted for these species using vials with one vs. two holes and showed that the seeding rate was higher by an average of 58% to 173% from a vial with two holes compared with one hole. For most plant species evaluated, the SH seeder was able to dispense as few as one to three seeds consistently. Seed discharge increased somewhat with increasing SH weight for all species evaluated. The SH seeder can be useful for interplanting sweet alyssum as an insectary plant for aphid (Aphidoidea) control between existing plants of organic lettuce (Lactuca sativa), and for intercropping cultivars of purslane as a novel vegetable in between transplanted organic broccoli (Brassica oleracea Italica group) plants. This novel seeding tool has many potential uses for direct, hand seeding in vegetable and herb production systems and in weed research trials. The seeder could be automated and made with a variety of alternative materials.
Rhuanito Soranz Ferrarezi and Donald S. Bailey
genus Ocimum comprises more than 30 species, and is divided into basil types, which include sweet ( Ocimum basilicum ), lemon ( Ocimum citriodorum ), dwarf bush ( Ocimum minimum ), purple ( O. basilicum var. purpurescens ), and thai ( O. basilicum
How-Chiun Wu and Chun-Chih Lin
compounds, similar results have been reported for other phenolics under red light. Guo et al. (2007) showed that flavonoid biosynthesis in Saussurea medusa callus cultures was inhibited by red light irradiation. Similarly, leaves of Ocimum basilicum
Au Trung Vo, Imane Haddidi, Hussein Daood, Zoltan Mayer, and Katalin Posta
concentration) have been published in Ocimum basilicum plants inoculated with Rhizophagus irregularis ( Lee and Scagel, 2009 ). The mechanisms by which AMF alter the production of secondary metabolites in E. prostrata are still not clarified. Sand and peat
Noelle J. Fuller, Ronald B. Pegg, James Affolter, and David Berle
environmental factors on holy basil is lacking, but there have been many environmental studies on culinary basil ( Ocimum basilicum ). Eugenol content in culinary basil has been reported to increase under conditions of water stress, higher temperatures, and
Isidro Morales, Gabino Alberto Martínez-Gutiérrez, Cirenio Escamirosa-Tinoco, Cinthia Nájera, Tatiana Pagan Loeiro da Cunha-Chiamolera, and Miguel Urrestarazu
. Mesoam. 27 1 115 130 Chang, X. Alderson, P.G. Wright, C.J. 2008 Solar irradiance level alters the growth of basil ( Ocimum basilicum L.) and its content of volatile oils Environ. Expt. Bot. 63 216 223 Díaz-Pérez, J.C. 2013 Bell pepper ( Capsicum annuum