Fibrousness or toughness is a major factor influencing quality of vegetables; highly fibrous vegetables are unappealing to consumers. Fibrousness results from lignified cell walls in the pericycle and vascular bundles. Several methods have been used to determine fibrousness: the blender method (3), the cold water method (7), alcohol-insoluble solids (1), the fibrometer (6), the shear press (5), and machines such as the Instron Universal Testing Machine (4). While each of these methods is reliable for determining fibrousness of vegetable tissue, several require considerable time and/or expense. Also, in the case of the fibrometer, the results can be influenced by sample diameter (2). This note describes a simple, inexpensive procedure for determining fibrousness of vegetables using a juicerator.
High levels of sphagnum peat in the growing medium promoted growth of asparagus (Asparagus officinalis L. cv. Viking 2K) in a greenhouse study. Application of NH4NO3 > 1 g/pot (84 kg·ha-1 equivalent) was detrimental to root growth. High N rates and high organic matter levels decreased fibrous root development. Shoot dry weight was highly correlated with fleshy root number, root dry weight, and shoot vigor.
Clear visualization of asparagus (Asparagus officinalis L.) microspore nuclei with common stains such as acetocarmine or DAPI is difficult, hindering cytological analyses. The addition of saturated aqueous ferric chloride solution to Carnoy's I fixative (30 μL·mL-1) resulted in clear visualization of nuclei. A distinct nucleus was observed in uninucleate cells and the vegetative and generative nuclei were clearly visible in binucleate microspores. This method can be used reliably for determination of asparagus microspore developmental stage. Chemical name used: 4′,6-diamidino-2-phenylindole-2HCL (DAPI).
Increasing the concentration of sucrose in media containing 5 μm ancymidol increased rooting, with about 95% rooting of two asparagus (Asparagus officinalis L.) selections (Guelph-97, ‘Jersey Centennial’) obtained with 7% sucrose. In the absence of ancymidol, there was no evidence that increased sucrose concentration increased rooting. The increased rooting was not due to an osmotic effect, since the replacement of sucrose by an equimolar concentration of mannitol did not improve rooting. Chemical names used; 1-naphthaleneacetic acid (NAA), N-(2-furanylmethyl)-1H-purin-6-amine (kinetin), and α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol).
A potential allelochemical was isolated and identified from methanol extracts of asparagus (Asparagus officinalis L.) fresh root tissue. Fractions were collected by cellulose column chromatography and tested for inhibition by an asparagus seed germination bioassay. The fraction showing the greatest inhibition contained caffeic acid, as identified by melting point, thin-layer chromatography, and infrared spectrum analysis. Seed germination bioassays and greenhouse pot tests showed depression of seedling emergence when asparagus seeds were exposed to various dosages of crude filtrate, a methanol extract from crude filtrate, and caffeic acid.
One-year-old crowns of Asparagus officinalis L. cv. Princeville were grown for up to 2 years in pots containing a mineral soil. Nitrogen concentrations ranged from O to 340 kg N/ha. Increasing N fertilizer level resulted in a decrease in total crown fructose concentration and an increase in fern growth, both leveling off at higher N levels. Crown growth was maximized at intermediate N levels. To obtain maximum crown growth and total fructose concentration, while avoiding the excessive fern growth associated with higher N fertilizer levels, ≈57 kg N/ha should be applied to asparagus during the 2nd and 3rd years of growth.
Asparagus spears (Asparagus officinalis L.) stored 28 days at 2C in air, a flow-through controlled-atmosphere (CA) system, or 14 days in polymeric film consumer packages were evaluated in respect to compositional and quality changes. CA-stored spears retained more sugars, organic acids, and soluble proteins than spears stored in air. Spears stored in vented consumer packages had a useful life of 14 days, whereas those in nonvented packages started to break down after 8 days. Spears from vented packages lost more weight but retained more sugars and organic acids than those from nonvented packages.
Four planting depths and two time intervals (1 or 2 years) between transplanting and initial year of harvest of asparagus (Asparagus officinalis L.) yield were compared for 4 years. Spear emergence and initial spring harvest date were delayed and susceptibility to spring frost injury was decreased with increasing planting depth (from 5.0 to 20.0 cm). Over years, crown depth increased for the shallowest planting and decreased for the deepest planting. Harvesting after 1 year vs. 2 years from planting reduced yield. There were no significant interactions between year of initial harvest and depth of planting.
One-bud segments from moderately vigorous shoots of aseptically grown Asparagus officinalis L. stock plants were cultured on modified Murashige and Skoog’s medium (MMS) containing 0.1 ppm of α-naphthaleneacetic acid (NAA) and 6-furfurylamino purine (kinetin). Only 35% of the cultures developed into rooted plantlets. A high percentage of nonrooted plantlets were induced to root by reculturing on fresh MMS medium containing 0.1 ppm NAA. More plantlets rooted if they were older than 4 weeks when recultured on the fresh medium.
Four asparagus (Asparagus officinalis L.) cultivars, UC 157, Syn 4-56, Mary Washington, and Viking KB3, were stored at 2C, and their quality was evaluated during 3 weeks of storage, There were no cultivar differences in respiration, weight gain, or soluble solids concentration initially or after storage. After 3 weeks of storage, the cultivars UC and S4 were more vividly green and less seedy than MW or VK, but UC exhibited slight to moderate chilling injury. Spears of S4 and VK had better overall appearance than MW or UC.