Three cold-climate strawberry production systems, conventional matted row, advanced matted row, and cold-climate annual hill plasticulture, were compared for consumer preference in a pick-your-own (PYO) setting. Replicated 6 × 15 m plots were established in 2002 in Maryland and cropped in 2003 and 2004. To simulate PYO marketing, volunteers were recruited to harvest 3.6-m plots in each of the three production systems and to complete a five-part questionnaire. The questionnaire collected demographic information and allowed volunteers to compare the three systems both prior to and after their harvesting experience. Harvests were carried out twice weekly, with 75 participants in 2003 and 45 participants in 2004. The 2003 season was cool and wet, with frequent rainfall and a high incidence of fruit rot. Spring 2004 was unseasonably hot, resulting in an unusually short harvest season. Consumer preference differed between years and among harvests within a season. The annual hill system was favored early in the 2003 season, with preference shifting to the other systems as the season progressed. The advanced matted row was favored early in the 2004 season. Many of the participants' comments, both positive and negative, were directed at the plastic mulch and raised beds. In several cases, participants indicated that their preferences after picking from each system did not match their initial impressions. Implications of this research to the social components of sustainability will be discussed.
Matthew D. Stevens, Judith A. Abbott, John D. Lea-Cox and Brent L. Black
Elden J. Stang and Gavin G. Weis
`Raritan' and `Guardian' strawberry were grown in the matted row system with controlled plant densities of 1, 2, 3, 4 or 5 plants/0.09m2 for comparison to a non-thinned matted row averaging 9 plants/0.09m2. Nitrogen treatments were superimposed on plant spacings at 3 week intervals in preharvest and postharvest applications. Total seasonal available N was 0, 36, 54 and 76 kg/ha. Fruit yield per plant decreased as plant population increased. Berry size declined with increased plant population but number of fruit per plant was not influenced. For both cultivars, plant populations of 4 to 5 plants/0.09m2 resulted in maximum fruit yield. Number of branch crowns for all treatments was 2.5-3.5/plant in the second growing season. Branch crown numbers were reduced with higher plant populations. N effects were independent of plant population effects and did not compensate for lower yields at low plant populations in more or larger berries. Optimum water management may be more important than N fertilizer in determing strawberry plant growth and yield.
Joseph A. Fiola and Robert J. Lengyen
High-density, annual, strawberry production systems (“plasti-culture”) have shown high productivity under New Jersey conditions; however, cultural practice and variety research is needed to increase profitability. The system includes raised beds, plastic mulch, trickle irrigation, and double-row 12 × 12-inch plant spacing. Polypropylene floating rowcovers were applied in December and removed in early April when flowers were visible under the cover. Treatments included comparisons of plugs and dormant crowns of the cultivars Chandler and Allstar, planted at multiple planting dates, on white or plastic mulch, in “matted-row” (single row at 18-inch spacing; peg runners through plastic) or high-density production systems. The plug plants were superior to dormant crowns. Black plastic was best all planting dates with plugs; `Allstar' performed best on black on the early planting dates, while `Chandler' preferred the white for the early planting dates. Both `Allstar' and `Chandler' had commercially profitable yield, fruit weight, and quality. “Matted-row” system on plastic is high-yielding but labor-intensive. Late-summer plugs on black plastic is best overall.
Rumphan Koslanund and Douglas. D. Archbold
Strawberry cultivars grown for “pre-picked” markets need to maintain quality during short-term postharvest storage in contrast to those destined for “U-pick” harvest. However, very little information is available on berry quality during postharvest storage of cultivars grown in matted-row culture in eastern North America. To determine how rapidly berry quality may change and identify cultivars best-suited for pre-picked markets, the postharvest performance of 16 cultivars grown in matted rows was compared. Berries were sampled at harvest, after 3 days of 4 °C storage within sealed plastic bags, and after 3 subsequent days at 20 °C. Quality traits assessed included fruit firmness, color, titratable acidity, pH, soluble solids, and percent weight loss. At harvest, berry quality varied by cultivar and from early to late harvest dates. Berry quality changed very little during 4 °C storage. During the subsequent 20 °C storage, berry quality traits changed more for some cultivars than others. In particular, soft fruit at harvest and/or a rapid decline in berry firmness indicated that several cultivars were not suited for short-term storage. Based on the cumulative data, several cultivars can be identified as better suited for pre-picked markets.
Andrew R. Jamieson and Katherine Sanford
Twelve clones of `Blomidon' strawberry (Fragaria xananassa) exhibiting a range of severity of June Yellows symptoms were grown in field plots to measure effects on productivity. Field plot layout was a randomized block design with four blocks. Plots were matted rows developed from five plants spaced at 45 cm inrow. Fruit samples were frozen and later analyzed for soluble solids concentration, total acidity, and pH. In the greenhouse, self-pollinated seedlings grown from these clones were rated for symptom expression as an additional measure of severity of June Yellows. Large differences in marketable yields were recorded, ranging from 1.94 t·ha–1 to 14.67 t·ha–1. Clones with severe symptoms produced smaller fruit. Small clonal differences were measured in total acidity and pH. A strong correlation was observed between the percentage of symptomless seedlings and the yield of the parental clone. This may lead to a test to predict whether a new cultivar will succumb to June Yellows.
A.W. Caylor, W.A. Dozier Jr., G. Wehtje, D.G. Himelrick, J.A. McGuire and J.A. Pitts
The postemergence-active herbicides lactofen, fomesafen, and acifluorfen were applied to established matted-row strawberry plants (Fragaria × ananassa) and evaluated for broadleaf weed control and foliar phytotoxicity. Strawberries were evaluated for yield and fruit quality. Treatments were applied following June renovation. All herbicide treatments resulted in acceptable control of broadleaf weeds present at the time of application; however, sicklepod (Cassia obtusifolia) germinated after herbicide application. All treatments caused foliar injury within 3 days after application. No injury symptoms were evident 21 days after treatment due to new foliage development. Fomesafen and acifluorfen were the only herbicides to suppress runner count. Yields the following year were not reduced by herbicide treatments. Chemical names used: (±)-2-ethoxy-l-methy1-2-oxoethyl 5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzate (lactofen); 5-[2-chloro-4-(trifluoromethyl)phenoxy] -N -(methylsu1fonyl)-2-nitrobenzamide (fomesafen); 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen).
Chrislyn A. Particka and James F. Hancock
Black root rot (BRR) is a widespread disease of strawberry (Fragari×ananassa Duchnesne) that causes the death of feeder roots and the degradation of structural roots. The major causal organisms of BRR include Rhizoctonia fragariae Husain and W.E. McKeen, Pythium Pringsh., and Pratylenchus penetrans (Cobb) Filipjev and Schuurmans Stekhoven. The current method of control for black root rot is methyl-bromide fumigation; however, methyl bromide is scheduled to be phased out in 2005, and its effects are short-lived in matted-row systems. The objectives of the study were to measure levels of tolerance to BRR in 20 strawberry genotypes and to determine which pathogens were present in the soil. The genotypes were planted in four blocks each of methyl-bromide fumigated and nonfumigated soil, and were evaluated for crown number, number of flowers per crown, yield, and average berry weight over 2 years. The results showed that all three pathogens were present in the field, and that there was a significant genotype × fumigation interaction for yield and crown number in both years. The cultivars Bounty, Cabot, and Cavendish, all released from the breeding program in Nova Scotia, displayed tolerance to the pathogens that cause BRR.
Douglas D. Archbold and Charles T MacKown
Three gel polymers, Hydrosource, REAP, and Agri-gel, wetted with solutions of 15N-ammonium nitrate, were evaluated for controlled release of fertilizer nitrogen (N) to strawberry (Fragaria × ananassa Duch.) in the greenhouse and field. Container-grown plants of `Earliglow' and `Allstar' were harvested every 2 weeks for 8 weeks. Field-grown plants of the same cultivars were collected from matted rows after harvest, and fruit were collected during harvest. Plant and fruit tissues were analyzed for total % N and atom % & 15N, and total fertilizer N recovery was calculated. For the container-grown plants, total % N differed by cultivar, `Earliglow' > `Allstar', and harvest date, declining during 8 weeks. Treatment effects on total % N were observed only in the field study, with Agri-gel showing the highest value. In the greenhouse study, Hydrosource and Agri-gel gave the highest tissue enrichments from fertilizer N. In the field study, REAP and Agri-gel gave the highest enrichments. In spite of the greater tissue enrichments, however, no gel polymer significantly increased total fertilizer N recovery in either study.
D.T. Handley and M.A. Schupp
Twelve strawberry varieties established in matted row plots in 1993 were treated with insecticides for tarnished plant bug and strawberry bud weevil or left untreated during 1994. Honeoye and Cavendish had the highest yields of marketable fruit. Oka, Jewel, Chambly, and Kent also had relatively high yields. Lateglow, Blomidon, Seneca, NY 1424, Settler, and Governor Simcoe had lower yields than the other varieties. Tarnished plant bug populations were very small during the 1994 season and the injury levels observed were relatively low. Feeding pressure on the plants may have been too low for all differences in susceptibility between varieties to be expressed. Governor Simcoe, Cavendish, and Oka had the lowest injury levels. Kent, Lateglow, and Seneca had the highest levels of injury. Insecticide sprays significantly reduced injury for all varieties except Cavendish and Governor Simcoe. The number of flower buds killed by strawberry bud weevil differed very little between varieties and spray treatments. No obvious differences in susceptibility to this injury were observed in this trial.
Chrislyn A. Drake* and James F. Hancock
Black root rot is a serious disease of strawberry (Fragaria ×ananassa Duch.) that causes the death of feeder roots, the degradation and blackening of structural roots, and an overall decrease in plant vigor and productivity. The causal organisms of black root rot are Rhizoctonia fragariae, Pythium sp. and Pratylenchus penetrans (the root lesion nematode). Each organism alone can cause extensive damage to strawberry roots, but studies have shown that black root rot may be more severe when all organisms are present, indicating there is an interaction between the fungal organisms and the nematode. The current method of control for black root rot is methyl-bromide fumigation; however, methyl bromide is to be phased out by 2005, and it is not very effective in perennial matted-row systems. The objectives of the study are to measure levels of tolerance to black root rot in 21 strawberry genotypes. The genotypes were planted in four blocks each of methyl-bromide fumigated and non-fumigated soil, and were evaluated for crown, runner, and inflorescence number; yield; average berry weight; and root health. `Cavendish', `Kent', `Midway' and `Winona' showed the highest degree of tolerance, while `Jewel', `Mesabi', and LH50-4 (a F. virginiana genotype) were the poorest performers.