`Jersey Giant' asparagus (Asparagus officinalis L.), grown in an Enders silt loam mineral soil, was given 80 kg supplemental N/ha either before or after the harvest season. Neither N application timing affected spear yield, objective color, or pigment concentration. Early supplemental N application decreased K concentration in white spears and Ca concentration in green spears. Green asparagus contained higher total-N, K, P, S, Ca, Mg, Fe, Zn, Al, Mn, and Cu concentrations but a lower soluble solids concentration (SSC) and NO3 than did white asparagus. As the cutting season progressed, spear SSC and S, Ca, NO3 (NO3 in white spears only), Zn, Mn, and Cu (Cu in white spears only) concentrations decreased, but spear K and Al (Al in white spears only) increased on a dry-weight basis. Fall residual soil NO3 levels were not affected by N application timing, but organic matter (percent) was lower in soil that received early supplemental N.
The effect of soil moisture levels on the yield and dry matter accumulation of asparagus (Asparagus officinalis L) using the motherstalk method was examined in a greenhouse study. This technique allows for a spear to develop a mature fern while permitting harvest of later-developing spears. The motherstalk treatment resulted in significantly heavier spears as compared to the conventional practice without a motherstalk and harvesting all spears. In addition, crown weights between the motherstalk and the nonharvested treatment were similar at the end of the 12-week harvest period, but significantly lower when spears were harvested without the benefit of a motherstalk. Optimizing soil moisture significantly increased yield in the motherstalk treatment and increased the fern dry weight but had no effect on crown dry weight. Our results indicate that the motherstalk system may allow for extended asparagus harvest in temperate areas but soil moisture may need to be carefully monitored to use this technique.
Mineral nutrients were determined in green and white `Jersey Giant' asparagus (Asparagus officinalis L.) spears grown in 1991 near Booneville, Ark. Green spears had higher concentrations of tissue N, K, P, S, Na, and Zn; similar levels of Fe, Al, and Cu; and lower levels of NO3 than white spears grown under opaque plastic rowcovers or under sawdust mulch. Levels of Ca, Mg, and Mn were higher in plastic-grown white spears than in those grown in sawdust. The spear tip contained higher concentrations of K, S, and Cu than the butt. Less NO3, Fe, and Al were in the tip than in the butt. Spear distribution gradients for K, Fe, and Cu were linear, whereas S and NO3 gradients were both linear and quadratic. Nitrogen, P, Ca, Mg, Zn, Al, and Mn levels were influenced by spear production method and spear segment.
New Jersey `Syn 4' asparagus (Asparagus officinalis, L.) was grown on a sandy loam soil to compare plant survival and yield of asparagus grown from crowns and transplants under four irrigation treatments: sprinkler (SPR), surface trickle (ST), subsurface trickle (SST), and no irrigation (NI). While plant survival of crowns was not appreciably influenced by any irrigation treatment, survival of transplants was significantly increased by SST. Total and marketable yields from crowns and transplants were similar in the first harvest season (year 3). However, in years 4 and 5, the yield of crowns was higher than that of transplants. Subsurface trickle increased yield from transplants in years 4 and 5 and increased yield from crowns in year 5. All irrigation methods significantly increased both spear production (spear/ha) and average spear weight. Subsurface trickle irrigation resulted in the largest increase over NI in total yield and spear production.
This study was carded out on Asparagus (Asparagus officinalis L.) during the two successive seasons of 1987/1988 and 1988/1989 at the Agricultural Experimental Station of National Research Center at Shalakan Kaloubia Governorate The investigation was aimed to study the effect of cultivar, propagation methods and polyethylene mulching on plant growth and performance
The application of plastic mulching caused signficant increases in plant height. number of shoots. number of branches, fern fresh and dry weight and roots an rhizome fresh and dry weight
Covering the soil surface with black and transparent polyethylene enhanced the vegetable growth of asparagus plant significantly as compared with unmulched treatments. Mulching with transparent polyethylene increased soil temperature over black polyethylene mulch and both treatments were higher in soil temperature than the control. Concerning the variation existed among cultivars, UC 157 F1 showed a significant increment in vegetable growth compared with UC 157 F2.
One-year-old crowns of `Jersey Giant' asparagus (Asparagus officinalis L.) were forced into spear production at 28C in darkness. Total spear fresh weight and number per square meter responded quadratically to the percentage of sand incorporated in Pro-Mix BX (PMX) peat-lite medium, with maximum yields at 25% to 75% (by volume) PMX. In a second study conducted at 22 and 28C, total spear fresh weight and number per square meter for 96 days of harvest were similar when grown in weathered, spent mushroom compost (SMC) or 1 PMX: 1 sand (v/v), but were lower than those grown in PMX. The lower temperature caused heavier individual spears, while the higher temperature stimulated earlier spear production. During the first month of harvest at 22C, the total number and fresh weight of spears in SMC were 11% and 17% less, respectively, than in PMX. SMC may be a low-cost forcing substrate for white asparagus.
Microsporogenesis was studied in 42 randomly chosen Fz plants of garden asparagus (Asparagus officinalis L. cv. UC 157) (2n = 2x = 20) that had been previously screened for production of pollen of heterogeneous size. At the tetrad stage, the average frequencies of tetrads, triads, and dyads were 58.9%, 15.4%, and 25.9%, respectively. Dyads and triads originated from the lack of chromosome migration toward opposite poles at anaphase II in either one or both cells of a microsporocyte, followed by the absence of cytokinesis in telophase II. The resulting 2n microspores were, therefore, genetically equivalent to second meiotic division restitution products. The observation that all plants examined produced 2n microspores in high frequencies is taken as an indication that the modified meiosis in these plants is under genetic control.
Commercial asparagus (Asparagus officinalis L.) is currently planted from seed but there is a growing interest in the use of tissue culture clones. The worldwide occurrence of asparagus virus I (AV-I) and asparagus virus II (AV-II) in asparagus production areas has led to an investigation of the effect of these viruses singly and in combination on the propagation of asparagus via tissue culture. Bud explants from field-grown, virus-infected asparagus plants were cultured in-vitro to induce shoots and roots. Explants derived from singly or doubly-infected plants were slow to develop roots and often died in culture. The four virus groups were ranked for the explants' capacity to produce roots and shoots: virus-free > AV-II > AV-I> AV-I and AV-II. Plants derived from explants of AV-II-infected plants exhibited a mild weight reduction after three months in the greenhouse. Greater reductions were associated with AV-I and double infections when compared to healthy controls.
Spraying 9-month-old UC157F1 asparagus plants (Asparagus officinalis L.) with aqueous solutions of GA4/7, BA, and promalin ranging from 0 to 200 ppm in 200-ppm increments and using the mother-stalk method showed that BA continued to produce the most marketable shoots and obtained a higher level of effectveness. GA4/7 showed significance on several days during the harvest period. On the final day, there was no significant difference found for either GA4/7 or promalin. BA produced marketable shoots earlier than promalin, but in the end, both these chemicals were equally effective. Early interaction with GA4/7 × BA resulted in delayed shoot emergence. Promalin is a mixture of GA4/7 and BA.
Asparagus (Asparagus officinalis) has great potential for production in the southwestern desert areas. Light, moderate and heavy harvest regimes were imposed on a one year old planting of `Mellowland Select' to determine the optimum duration of Spring harvest. There were no differences in mean spear weight or number of spears per plant in response to cutting pressure in 1987 or 1988. In 1989 both the light and heavy cutting regimes resulted in spears weighing 2.0 and 1. 5 grams less, respectively, than the moderate treatment and in fewer spears per plant. Consequently, 587 and 670 fewer kg/ha were produced in the lightly and heavily harvested plots in the third year. Total storage root carbohydrates were higher in the moderately harvested plots prior to harvest and again after fern production resumed in the third year. 1990 harvest data and implications for fall harvested or double-harvested asparagus will be discussed.