Estimates of heritability in a blanched asparagus population

To estimate the heritability values of characters frequently used as selective criteria, 32 half-sib families obtained from selected plants of three populations of the asparagus variety Argenteüil were evaluated in a randomized complete block design. The following characters were measured: days to emergence of the first spear, number and diameter of spears, number of stalks, plant height and average weight. The values of realized heritability were estimated and were compared with those obtained by the parent-offspring regression method. Phenotypic correlation coefficients between the different variables were significant. The values of realized heritability for most of the variables were moderate to high (between 0.18 and 0.68), except for days to emergence; lower values were obtained by the regression method. As there was a high degree of heritability, additive genetic factors contributed significantly to the genetic variance, which would allow the selection of phenotypically superior plants for asparagus improvement projects.     

Activities of enzymes involved in lignification during the postharvest storage of etiolated asparagus spears

The content of lignin and the activities of 5 enzymes involved in lignification were monitored along the length of etiolated spears of asparagus ( Asparagus officinalis L., INRA Fl male hybrid n°156) stored for 22 h with their base in air (control), water or water containing the ethylene antagonist, silver thiosulfate (STS). At the time of harvest the lignin content increased basipetally, as did the activity of all the enzymes studied, viz., phenylalanine ammonia lyase (PAL; EC 4.3.1.5), hydroxycinnamate: CoA ligase (HCoAL; EC 6.2.1.12), cinnamoyl-CoA reductase (CCR: EC 1.2.1.44), cinnamyl alcohol dehydrogenase (CAD; EC 1.1.1.195) and syringaldazine oxidase (SyrOx. a peroxidase [POD; EC 1.11.1.7] with syringaldazine as substrate). Neither the lignin content nor the activity of any enzyme changed in the spear apex during storage, regardless of treatment. In the spear base. all enzyme activities decrased during the first 2 to 4 h in every storage treatment. Subsequently. PAL and HCoAL activities remained constant. whereas the activities of CAD and SyrOx gradually increased. Lignification in the spear base was not affected by storage in air. However, storage in water increased lignin formation and SyrOx activity, whereas treatment with STS prevented both of these increases. The results indicate that postharvest lignification in etiolated asparagus spears is caused primarily by enhanced SyrOx activity, and that ethylene is involved in the control of this activity.     

Isoforms of glutamine synthetase in asparagus spears: the cytosolic enzyme increases after harvest

Two distinct forms of glutamine synthetase (GS) have been identified in the spear tip tissues of harvested asparagus (Asparagus officinalis L. cv. Limbras 10). The GS activities were separated by anion exchange chromatography. They have distinct kinetic properties and contain polypeptides of different sizes, and the abundances of the GS isoforms change differently after harvest. Plastid GS has a 44 kD polypeptide, and during the post-harvest period the abundance of this polypeptide declined dramatically. After 5 d, the activity of plastid GS had declined to just 20% of that at harvest. Cytosolic GS has a 40 kD polypeptide and is the major constituent of the GS activity present at harvest (73% of total). After harvest, cytosolic GS activity declined by half and then, at 3 or 4 d after harvest, rose to 80% of the cytosolic GS activity present at harvest. The nitrogen metabolism of asparagus spears is significantly altered as the tissues deteriorate rapidly after harvest. We demonstrate that cytosolic GS activity increases during the post-harvest period and is likely to be a critical feature of the physiology of the tip of a harvested asparagus spear.     

Occurrence of fumonisins in asparagus (asparagus officinalis L.) and garlic (allium sativum L.) from Germany

Fusarium proliferatum is able to produce fumonisins and is considered a pathogen of many economically important plants (e.g. corn, rice, asparagus) [1]. The occurrence of fumonisin FB₁ inF. proliferatum infected asparagus spears from Germany was investigated using a liquid chromatography/electrospray ionization-mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB₁-d₆ as internal standard. Asparagus samples were harvested in July 2000 and screened forFusarium species. AltogetherF. oxysporum, F. proliferatum and F. sambucinum were isolated from the spears. The samples infected with F.proliferatum were subsequently analyzed for fumonisins. FB₁ was detected in 9 of the 10 samples in amounts ranging from 36.4 ng/g to 4513.7 ng/g (based on dry weight). Fumonisins FB₂ and FB₃ were found in six samples in lower concentrations. In asparagus spears of June 2002 we could findF. proliferatum in 6% of the samples, however no fumonisins were detectable. Furthermore the capability of producing FB₁ by the fungus in garlic bulbs was investigated. Therefore garlic was cultured inF. proliferatum contaminated soil and the bulbs were screened for infection with F.proliferatum and for the occurrence of fumonisins by LC-MS. F.proliferatum was detectable in the garlic tissue and all samples contained FB₁ (26.0 ng/g to 94.6 ng/g). This is the first report of the natural occurrence of FB₁ in German asparagus spears and furthermore our findings suggest a potential for natural contamination of garlic bulbs with fumonisins. For detailed results and methods see Ref. [2].     

Physiological changes in asparagus spear tips after harvest

To extend our understanding of the physiology of asparagus after harvest, changes in respiration rate, protein and amino acid complement, and ultrastructure of tip sections (0–30 mm) of asparagus spears ( Asparagus officinalis L. cv. Limbras 10) were investigated. Spears had been stored for up to 4 days in the dark at 20°C. Respiration rate (carbon dioxide efflux) declined rapidly after harvest before stabilizing at 12 h at ca 50% of the rate at harvest. Protein, amino acid, and ammonium content of tip sections of 180 mm spears (intact tip sections) during storage, and comparable sections; excised from spears at harvest and subsequently stored (excised tip sections), were compared. Total protein content of intact and excised tip sections increased ca 10% 6–12 h after harvest, and then declined to ca 85% of harvest levels at 48 h. Gel electrophoresis in the presence of sodium dodecyl sulphate revealed the net loss of specific proteins at 48 h. Free amino acid content of excised tip sections declined to ca 75% of harvest levels 12 h after harvest, and then increased to 150% of harvest levels by 48 h. Glutamine levels declined rapidly after harvest, and asparagine content increased ca 200% at 24 h. Similar trends in free amino acid content were found in sections of intact tips. Ammonia (ammonium ions) accumulated to ca 0.3% dry weight at 48 h in both intact and excised tip sections. Ultrastructural studies revealed that tonoplast breakdown commenced 48–96 h after harvest. Results are discussed in relation to the sequence of physiological events following harvest and the timing of mechanisms responsible for their initiation.     

The effect of asparagus virus infection on asparagus tissue culture

The impact of asparagus virus I (AV-I), a potyvirus, and asparagus virus II (AV-II), an ilarvirus, on micropropagation of field-grown asparagus was studied. Apical shoot tips excised from singly or doubly-infected plants were slow to develop roots and had a 15 to 75% reduction in survival in culture, respectively, compared to those excised from virus-free plants. The four virus infection groups were ranked: virus-free >AV-II>AV-I>AV-I & II for capacity of explants to both root and survivein vitro. Micropropagated plants infected with AV-II exhibited slight reductions in fresh and dry weights, with greater reductions associated with infection with AV-I and double infection, compared to the virus-free controls. Eighty-one virus-infected apical shoot tips yielded 7 (8.6%) virus-free clones, as determined by rub inoculation on indicator plants.     

Fumonisins production by Fusarium proliferatum strains isolated from asparagus crown

The present work deals with the capability for producing fumonisin by Fusarium proliferatum strains isolated from asparagus in China. Fifty of F. proliferatum strains were randomly selected and incubated on cultures of maize grain and asparagus spear, respectively. Fumonisin levels (FB₁ and FB₂) were determined by high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The results showed that all 50 strains produced fumonisins in maize culture within a wide range of concentrations, 10–11,499 μg/g and 2–6,598 μg/g for FB₁ and FB₂, respectively. On culture of asparagus spear,48 strains (96%) produced fumonisins in the range 0.2–781.6 μg/g and no detected to 40.3 μg/g for FB₁ and FB₂, respectively. All of F. proliferatum strains produced much higher levels of FB₁, FB₂ and total fumonisins (FB₁ + FB₂) in maize grain culture than in asparagus spear culture. Meanwhile, fumonisin B₃ (FB₃) was identified in all maize culture extracts and most of asparagus spear culture extracts. This is the first study carried out the fumonisin-producing ability of F. proliferatum strains isolated from asparagus in China. The information obtained is useful for assessing the risk of fumonisins contamination in asparagus spear. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Identification and Characterization of an mRNA Encoding a Proline-Rich Protein that Rapidly Declines in Abundance in the Tips of Harvested Asparagus Spears

We previously isolated a cDNA clone, pTIP13, whose homologousmRNA rapidly declined in abundance in the tips of harvestedasparagus (Asparagus officinalis L.) spears [King and Davies(1992) Plant Physiol. 100: 1661]. In order to identify factorsregulating the postharvest deterioration of asparagus, we havenow sequenced the pTIP13 cDNA, derived the encoded amino acidsequence and determined the cellular location of pTIP13 mRNAby in situ hybridization. pTIP13 encodes a derived protein thatis rich in proline (22.3%), but also has a high content of lysine(15.2%) and threonine (14.1%). The proline residues are locatedin motifs at the amino-terminal region of the protein. The carboxyl-terminalregion of the derived protein has a high leucine content andshares >64% amino acid identity with derived proteins identifiedfrom cDNA clones to cell wall protein precursor mRNAs obtainedfrom soybean hypocotyls, alfalfa roots, and tomato fruit. GenomicSouthern analysis suggests that pTIP13 is encoded by a single-copygene in asparagus. pTIP13 mRNA was localized to specific celltypes in the young bracts of the asparagus spear tip. The resultsprovide new information on the complexity of tissue responsesin the tips of asparagus spears following harvest. (Received February 5, 1996; Accepted May 16, 1996)     

Heritability and expected selection response for yield traits in blanched asparagus

Despite the continuous breeding that has been conducted with asparagus (Asparagus officinalis L.) since the beginning of the last century, there is little information on parameters for predicting direct and indirect selection response. Yield traits for blanched asparagus production were studied along a two-year period in a half-sib family population planted in Zavalla, Argentina. Half-sib family mean heritability values were low for total yield and marketable spear number (0.31 and 0.35), intermediate for marketable yield and total spear number (0.55 and 0.64), and relatively high for spear diameter and spear weight (0.75 and 0.74). An average increase in marketable yield of 15.9% is expected after each cycle of selection of the top 5% of the families. Total yield failed to express significant genetic correlations with any of the yield components; meanwhile marketable yield showed highly significant relations with market spear number (0.96) and spear weight (0.89). Indirect selection response over yield components (CRx) failed to be advantageous over direct selection (Rx), since the ratio CRx/Rx was always equal or below unity.     

Inoculum sources of Fusarium oxysporum f.sp. asparagi in asparagus production

Fusarium oxysporum f.sp. asparagi (Foa) incites crown and root rot of asparagus which causes early decline of asparagus plantings. The aim of the present study was to identify the main inoculum sources of the pathogen in the Netherlands. As has been reported for foreign seed lots, Dutch seed lots can be infested with Foa at low levels. We found that seed infestation occurs mainly during the seed harvesting process through infested soil adhering to fallen berries. Soil samples from 59 fields without a history of asparagus growing and differing in their distance from asparagus plantings were tested for infestation with Foa, using a bioassay with asparagus as a bait plant. A high correlation was found between the incidence of infestation and proximity to asparagus fields; Foa was found in 69% of the samples from fresh fields in an asparagus production centre, and in only 6% of the samples from fields at a distance of 1 km and more from asparagus fields and outside a production centre. To evaluate planting material as an inoculum source of Foa, 49 lots of one-year-old crowns from 23 nurseries were collected and rated for disease symptoms. Infestation was found to be common with only two lots free of symptomatic plants. Most of the lots had more than 75% of symptomatic plants. Although most of the plants were infested, they showed only slight root rot symptoms. The procedure for production of Foa-free planting material is discussed. Persistence and infestation of asparagus root residues in former asparagus fields was assessed by retrieving the residues from eight former asparagus fields with an asparagus-free period of one to 25 years, and three fields with a standing asparagus crop. Even after an asparagus-free period of 25 yr asparagus root residues were retrieved from soil, although at low levels. Mean population densities of Fusarium spp. declined from 2 times 10⁶ to 1 times 10⁵ colony forming units g^_1 air-dry root tissue during the first 10 years and were still > 10⁴ c.f.u. g“¹ air-dry root tissue 20 to 25 yr after asparagus produced was stopped. The population was dominated by F. oxysporum. Eighty-three of the 112 isolates (74%) of F. oxysporum belonged to the forma specialis asparagi. The proportion of Foa in the population did not decrease in time. It was concluded that persistence of Foa in asparagus root residues is a major reason for its long-term survival.     

Fusarium Species Colonizing Spears and Forming Mycotoxins in Field Samples of Asparagus from Germany and Poland

The occurrence of Fusarium spp. and associated mycotoxins in asparagus spears was evaluated in Poland in 2002 and 2003 and in Germany in 2002. Spears of two cultivars, Eposs and Gijnlim, were collected from two locations in Poland, Swidwowiec and Poznan, on sandy and sandy loam soil, respectively. Fusarium oxysporum and F. proliferatum were detected at an average incidence of 38.3% and 15.8% in the spear sections sampled, respectively. In stands of 11 (tested) cultivars of asparagus sampled in Germany on sandy soil, the same species dominated, however, they were less frequent than in Poland (26.6% and 5.6% of the spears infected with F. oxysporum and F. proliferatum, respectively). Chemical analyses revealed that fumonisin B₁ (FB₁) and moniliformin (MON) were present in some of the spears sampled in Poland. FB₁ was not found and MON was not assessed in spears sampled in Germany in 2002, but F. proliferatum was able to form the toxin in vitro in the range from 101.4 up to 205.8 μg/kg maize kernel substrate. Asparagus samples in Poland contained FB₁ at up to 5.6 μg/kg spear fresh weight. The highest MON concentration (1350 μg/kg) was detected in cultivar Eposs in Marcelin, Poland, in 2002. MON and FB₁ were found in spears infected by both F. oxysporum and F. proliferatum, however, only the latter fungus was able to synthesize both toxins.     

Fusarium asiaticum: an Emerging Pathogen Jeopardizing Postharvest Asparagus Spears

Asparagus spears are usually vulnerable to pathogenic micro‐organisms. In this study, 217 pathogens were isolated from symptomatic asparagus, and one highly virulent fungus (designated EXAP‐08) isolated from the rotted asparagus spears in cold storage was characterized in detail. Koch's postulates were checked through pathogenicity tests, indicating that EXAP‐08 infection could cause reproducible rot symptoms similar to those observed on naturally infected asparagus spears, and the pathogenicity of EXAP‐08 was also relatively higher than other Fusarium pathogens, especially at 4°C. Through morphological and molecular identification, EXAP‐08 was characterized as Fusarium asiaticum. This identification was further confirmed by phylogenetic analysis with the Histone gene H3 of EXAP‐08 and other Fusarium species. EXAP‐08 also belongs to 3A‐DON (3‐acetyl‐4‐deoxynivalenol) chemo‐type, and the mycotoxin was detected during the infection of plant, implying the potential risks of mycotoxin contamination in fresh crops infected by this pathogen. Thus, this emerging pathogen threatening edible safety of asparagus spears should deserve particular quarantine inspection in the future.     

Spargelstangenuntersuchungen zur Haupterntezeit auf Infektionen mitFusarium spp. und Kontaminationen mit Fumonisin B1

Asparagus spears collected from a total of six commercial plantings in Austria during the main harvest periods in May and June of 2003 and 2004 were examined for endophytic colonization byFusarium spp., particularlyF. proliferatum. Potentially toxigenic fungi such asF. proliferatum were isolated and identified by morphological characteristics using light microscopy. Fumonisin B₁ inF. proliferatum-infected asparagus spears was detected with IAS-HPLC-FLD or HPLC-MS/MS. The identity of endophytic fungi colonizing of a total of 816 individual spears was determined. The incidence of infection byF. proliferatum and otherFusarium spp. was highly dependent on location and sampling date. The dominantFusarium species among the endophytic microflora wasF. oxysporum. Other frequently isolated species includedF. proliferatum, F. sambucinum, F. culmorum, F. avenaceum andF. equiseti. The incidence ofF. proliferatum-infected asparagus spears was less than 10% at four of the six sampling locations. At the two remaining locations, 20–47% of the spears examined were infected withF. proliferatum. Further exploration of FB₁ generation in asparagus is required because the low levels of FB₁ (10–50 (μg/kg) detected in harvested spears in 2003 and 2004 cannot be explained by the results of this study.

     

Cell wall biochemistry and biomechanics of harvested white asparagus shoots as affected by temperature

The effects of temperature on the dynamics of changes in shoot mechanical properties, cell wall components, relevant soluble sugars and respiration activity of harvested white asparagus spears were investigated during a 7-day storage period. All functional cell wall components of asparagus spears increased closely temperature dependent. The content of soluble glucose declined with a similar temporal dynamics and to a comparable degree, indicating a major carbon flow of this storage sugar into cell walls (60–70%). Irrespective of temperature, the contents of stored soluble fructose and sucrose remained more or less constant. Lower temperatures reduced cell wall development but do not significantly affect the relative carbon flow from storage sugars into cell walls or maintenance respiration. Compared with cell walls, maintenance respiration is by far the smaller carbon sink in stored asparagus spears. Temperature differentially affects the absolute amount and the relative contribution of the different cell wall components and the temporal dynamics of changes in structural carbohydrate and lignin content. At higher temperatures, secondary cell wall thickening resulted mainly from a large increase in cellulose content. The pronounced increase in the fractions of cellulose and especially lignin may stress the important role of lignin in cell wall strengthening. While the fraction of cell wall proteins decreased, those of hemicellulose and the pectic components were not influenced.     

Host-plant finding by the asparagus fly, Plioreocepta poeciloptera (Diptera: Tephritidae), a monophagous, monovoltine tephritid

The role of various olfactory and visual stimuli was studied in host-plant finding by the asparagus fly Plioreocepta poeciloptera (Schrank), a monophagous monovoltine tephritid causing serious damage to asparagus spears. Volatiles released by asparagus plants were extracted by diethyl ether after cryotrapping concentration, and identified by gas chromatography-mass spectrometry. Twelve of the 13 compounds identified were tested using electroantennography to measure the response of the fly. Behavioural response was analysed using two different flight tunnels according to circadian rhythm, age and sex of adults, presence of the plant and of different coloured lures, presence of a male congener, or exposure to four pure asparagus odour compounds that elicited responses in electroantennography, i.e. hexanal, (E)-2-hexenal, (Z)-2-hexen-1-ol and decanal. Data showed that males locate the host plant more quickly than females. Females are attracted mainly by the blend of plant odour and male pheromone. Both sexes respond to a complex of stimuli only during the afternoon. These findings will be helpful in developing new and effective approaches to control this pest insect.     

Composition of the cell walls of different asparagus (Asparagus officinalis) tissues

Portions of stems from the base of asparagus spears (Asparagus officinalis L. cv. Connovor Collossus) were dissected to give the following tissues: (1) pith, which was free of vascular bundles, (2) two surrounding layers, parenchyma and fibre I and II (PFI and PFII), containing parenchyma and vascular bundles, (3) sclerenchyma sheath, (4) epidermis and sub-epidermal layers and (5) asparagus vascular fibre (AVF). The alcohol-insoluble residues (AIRs) from these tissues were shown to be free of starch. They were analysed for moisture and protein, and the component sugars were released by two hydrolytic procedures, which helped to distinguish the sugars from non-cellulosic polysaccharides and cellulose. The AIRs from pith and epidermal tissues were relatively low in xylose, but were rich in cellulosic glucose, and sugars associated with pectic polysaccharides such as galacturonic acid, galactose and arabinose. Their major component polysaccharides (in decreasing amounts) were inferred to be pectic polysaccharides, cellulose, and hemicelluloses. AIR from sclerenchyma was rich in glucose and xylose, suggesting the presence of much cellulose and (acidic) xylans. The AIRs of PFI, PFII and AVF contained significant amounts of xylose in addition tn other sugars, and the major polysaccharides inferred to be present were pectic polysaccharides, cellulose and hemicelluloses, a significant proportion of which may be acidic xylans. Methylation analysis of the AIRs confirmed the above inferences. The bulk of the glucosyl residues were (1–4)-linked, and there were small but significant amounts of (1–4, 6)-linked glucosyl residues (the linkage characteristic of xyloglucans) in all the preparations. The presence of (1–4)-linked galactosyl, (1–5)-linked arabinosyl, terminal galactosyl, terminal arabinosyl, (1–2)- and (1–2, 4)-linked rhamnosyl residues in all the AIRs except that from sclerenchyma, confirmed the presence of significant levels of pectic polysaccharides in all the parenchyma tissues. All the preparations containing vascular tissues contained significant amounts of (1–4)-linked xylosyl residues, probably derived from acidic xylans. Even in the AIR of pith, a significant amount of (1–4)-linked xylosyl residues were detected. This may be due to the ability of these cells and the parenchyma cells associated with the vascular bundles, to undergo lignification in mature asparagus plants.     

Uptake and Redistribution of 15N Within an Established Asparagus Crop after Application of 15N-labelled Nitrogen Fertilizer

The uptake and redistribution of ¹⁵N within a 6-year-old asparagus(Asparagus officinalis L.) crop were examined for applicationsof ¹⁵N-enriched ammonium sulphate (5 g N m^-2) either prior togrowth of foliage (commonly called 'fern'), prior to harvest,or early-harvest prior to the main period of spear (newly-emerged,edible, unexpanded shoot) production. During the harvest inspring, 38 kg N ha^-1 was removed in harvested spears, but thiswas small compared to the 710 kg N ha^-1 present in crowns androots. Limited uptake of ¹⁵ N occurred during harvest from thepre-harvest and early-harvest applications (11 and 4% of the¹⁵N applied, respectively) and the lack of plant uptake of Nfrom soil was also evident from an accumulation of inorganicN in unfertilized soil during spring. These results indicatethat N in spears was derived largely from remobilisation ofN stored in the crowns and roots. Most plant uptake of added ¹⁵N occurred during the first 8 weeksof foliage growth in summer, when 282 kg N ha^-1 had accumulatedin the above-ground foliage. After this 8 week period, foliagefrom the early-harvest treatment contained 24% of the ¹⁵N applied.Fifteen weeks later (late autumn), foliage was senescing andthe ¹⁵N content of senesced foliage in all treatments had declinedby 90% due to remobilisation and translocation into the crownand root tissue. Similarly, foliage N had declined from 282to 24 kg N ha^-1 and this remobilised N was equivalent to approximately40% of the total plant N present prior to foliage growth. During the subsequent spring period, the ¹⁵N enrichment of spearswas about twice that of the crowns and roots. Thus, there waspreferential remobilisation of recently-absorbed, stored N fornew spear growth.Copyright 1994, 1999 Academic Press Asparagus, Asparagus officinalis, nitrogen, ¹⁵N, redistribution, remobilisation, uptake     

The potential of Thelypteris palustris and Asparagus sprengeri in phytoremediation of arsenic contamination

The potential of two plants, Thelypteris palustris (marsh fern) and Asparagus sprengeri (asparagus fern), for phytoremediation of arsenic contamination was evaluated. The plants were chosen for this study because of the discovery of the arsenic hyperaccumulating fern, Pteris vittata (Ma et al., 2001) and previous research indicating asparagus fern's ability to tolerate > 1200 ppm soil arsenic. Objectives were (1) to assess if selected plants are arsenic hyperaccumulators; and (2) to assess changes in the species of arsenic upon accumulation in selected plants. Greenhouse hydroponic experiments arsenic treatment levels were established by adding potassium arsenate to solution. All plants were placed into the hydroponic experiments while still potted in their growth media. Marsh fern and Asparagus fern can both accumulate arsenic. Marsh fern bioaccumulation factors (> 10) are in the range of known hyperaccumulator, Pteris vittata Therefore, Thelypteris palustris is may be a good candidate for remediation of arsenic soil contamination levels of < or = 500 microg/L arsenic. Total oxidation of As (III) to As (V) does not occur in asparagus fern. The asparagus fern is arsenic tolerant (bioaccumulation factors < 10), but is not considered a good potential phytoremediation candidate.     

Shelf-life of stored asparagus is strongly related to post-harvest accumulated heat units

The effect of delay between harvest and hydrocooling, and of regimes of simulated air transport temperatures, on shelf-life of fresh asparagus were quantified. Shelf-life was strongly negatively correlated with the accumulated heat units experienced between harvest and post-transport handling. A 2-h delay in hydrocooling after harvest was similar to a 0.5°C higher temperature during a 2-day transit period in effect on shelf-life. It is essential for maximum shelf-life that asparagus be kept cold from the completion of hydrocooling until sale.