High density strawberry planting systems have increased yield and fruit quality, and allow greater production on small acreage. To adapt the system to New Jersey conditions, replicated plantings of `Chandler', `Tribute', and `Tristar' were established at 3 spacings and two planting dates (9/9, 9/15) in 1989, and two plant spacings and two planting dates (8/14, 9/7) in 1990. Plants were propagated as plugs from runner tips. The plantings were covered with floating row covers (polypropylene) in December, covers were removed in early April at 5% bloom. In 1990, `Chandler' yield increased as density increased, and decreased with later planting date. Fruit quality was very good; saleable % was over 90%. Size ranged from 8 to 21 g., and averaged from 12 to 17 g. for the various treatments. `Tribute' responded similar to `Chandler' but `Tristar' yield at 12″ was not significantly different than 6″, but greater than 9″. Size ranged from 9 to 19 g., and averaged from 10 to 14 g.; saleable % was over 85%. In 1991, 2 spacings (6″, 12″) and 2 planting dates (8/24, 9/7) were tested. The earlier planting date was superior to later; yields were not different between the 6″ and 12″ treatments (yield range: 3.8-5.4 T/A). Size was superior at wider spacing; day-neutral fruit size was small (avg fruit size range: 7.7-11.2g; high range: 10.1-17.4g).
Joseph A. Fiola, Peter Probasco, and Stephen Garrison
An RCB (4 replicates - 4 m plots) planting of `Chandler' was established to test the effects of planting date and floating row covers (FRC) in a high density strawberry planting system under NJ conditions. Transplant “plugs” from runner tips were planted on a double row (0.5 m × 0.3 m) on a raised plastic mulch bed (1.5 m centers), with trickle irrigation. Treatments included: plant 9/18/91 w/FRC on 10/7/92; plant 9/18/91 w/FRC on 12/2/92; plant 9/18/91 w/noFRC; plant 10/7/91 w/noFRC; plant 9/14/92 w/FRC on 10/7/92; plant 9/14/92 w/noFRC. In 1992, `Chandler' yield increased with earlier planting date and earlier FRC application (range: 8,600 to 13,400 kg/ha). There were no significant differences in cull or fruit weight. In 1993, there were no significant differences in 2nd year yield for 1991 treatments (range: 19,198 to 20,531 kg/ha). However, the 1992 treatments again showed the benefit of FRC (range: 13,437 to 20,531 kg/ha) for improved first year production. One year old plots had significantly larger average fruit weight than two year plots (range: 10.3 to 13.7 g). Early planting date with early applied FRC was the best treatment, combining high yield and good fruit weight.
Gary C. Pavlis and Joseph A. Fiola
Downy Mildew, Plasmopara viticola, causes major damage and economic loss to many wine grape cultivars grown in the Northeast. The purpose of this experiment was to test the efficacy of Vossen Blue (VB; iron pigment) in association with fungicides for the control of Downy Mildew disease of wine grapes in New Jersey. The experimental plot was a planting of Chancellor (10th leaf). Treatments (applied via back-pack sprayer) included no fungicide (NF), full fungicide (FF) (RCE commercial recs. half fungicide (HF), FF + 8%VB (FF8), HF + 8% VB (HF8), 88V B. Subjective (l-9) disease score for leaf tissue showed no statistical difference between the FF, FF8, HF and HF8 treatments however all showed superior Downy Mildew control to the 8% VB and the no fungicide control. Yield data indicated that the FF8 treatment resulted in higher yield (p is ≤ 0.01) than FF, HF and HF8. The NF and 8VB treatments resulted in the lowest yield. Compared to normal full fungicide, superior Downy Mildew control on the fruit was achieved by adding VB to full fungicide. These results are consist with previous experiments conducted on Seyval Blanc.
Joseph A. Fiola and Donald W. Schaffner
The major limiting factors for commercial marketability of strawberries grown in the Northeast is firmness and shelf-life. The major objective of the research is to study basic and applied aspects of exogenous calcium treatments on yield and quality of New Jersey grown berries. In 1990, 8328-1 and 8237-1 (NJUS advanced selections), and `Earliglow' and `Raritan' standards, were treated with 4 foliar Ca sprays (Nutrical) at 10 day intervals from bloom through harvest. In 1991, sprays (3) were applied at bloom, bloom+15 days, and pre-harvest. An `Earliglow' plot was utilized to test timing: bloom, mid-spray, or pre-harvest. Leaf and fruit samples were taken from treated and untreated plots prior to each application. Instron texture tests were performed to quantify firmness; a taste panel evaluated quality (color, texture, flavor, and overall quality). With multiple sprays, there were no significant differences in yield, fruit size, and Brix%, between treatments; however there were significant differences between genotypes and a genotype-by-treatment interaction. The lone bloom spray treatment reduced fruit size. Ethylene was reduced with calcium treatment, respiration was unaffected. Differences in flavor attributes were genotype specific.
Joseph A. Fiola and Gary C. Pavlis
Downy Mildew, Plasmopara viticola, causes major damage and economic loss to many wine grape cultivars grown in the Northeast. The purpose of the experiment was to test the efficacy of Vossen Blue (VB; iron pigment) in association with fungicides for the control of Downy Mildew disease of wine grapes in New Jersey. The experimental plot was a planting of `Seyval Blanc' (5th leaf). Treatments (applied via back-pack sprayer) included no fungicide (control I), full fungicide (FF) (RCE commercial recs; control II), FF + 4%VB, FF + 8%VB, 8%VB, Half Rate Fungicide (HF) + 4%VB, HF + 8%VB. There were no significant differences between treatments for total yield, average cluster weight, average berry weight, Brix %, and pH. Spectrophotometric (Hunter's Lab) analysis of foliage samples revealed that leaf samples from the VB treatments had greater green color (correlate: increased chlorophyll). Analysis of subjective (1-9) disease incidence data: FF8 significantly lower disease score that FF; FF4, HF4, HF8, and FF no difference. Compared to normal full fungicide: superior Downy Mildew control was achieved by adding VB to full fungicide; equal control was achieved with half fungicide and VB.
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.
Joseph A. Fiola and Harry J. Swartz
Raspberry cultivars and hybrids were screened for reaction to Verticillium alboatrum Reinke and Berth to determine the mode of inheritance of resistance and to assist in the development of resistant germplasm. Greenhouse-grown seedlings of an incomplete partial diallel of two black, purple, and red raspberry Rubus subgenus Idaeobatus progeny were root-dipped in a mycelial slurry and stem-inoculated with a conidial suspension of V. albo-atrum. Fourteen weeks after the initial inoculation, disease symptoms were observed in the seedlings. Disease symptom severity and percentage of black raspberry parentage in the seedlings were correlated (P ≤ 0.01; r 2 = 0.90). A similar significant (P ≤ 0.05; r 2 = 0.66) linear trend was found with fungus reisolation percentages, although isolation of the fungus from symptomless plants indicates Verticillium tolerance among genotypes in Idaeobatus. These trends, coupled with large significant general combining ability (P ≤ 0.01), suggest primarily additive inheritance of resistance. However, considering noninoculated control scores, the possibility of escapes, and skewing of populations, one may hypothesize a gene-gene model for symptom expression, with partial dominance of resistance alleles.
Joseph A. Fiola, Gojko Jelenkovic, and Gene Galletta
The major objective of the NJUS Strawberry Breeding Program is the development of early ripening cultivars with excellent fruit flavor and size for production under conventional matted-row, and high density annual production systems. In the 1993 replicated Step 3 trials (1991; 1992 planted), sixteen selections had higher yield than `Earliglow' (8127, 11312 kg/Ha), ranging from 8433 kg/Ha to 13334 kg/Ha. Thirty-one had higher weighted average fruit weight (WAFW) over the season than `Earliglow' (8.8 g; 8.4 g), ranging from 9.0 g to 12.3 g.
Selection for phenotype best suited for annual stem includes: low runnering, strong vigor, earliness, and large fruit size. In 1993 harvested Step III, four selections had comparable or higher yield (range: 12,866 to 27,128 kg/Ha) than `Chandler' (12,950 kg/Ha), as well as larger primary and WAFW (range: 13.5 to 16.4 g). All selections were significantly earlier than `Chandler'. In summary, the NJUS Strawberry Breeding Program has selections for the matted-row and annual production systems which are early, with excellent fruit flavor, size, and firmness for fresh market production.
Peter R. Probasco, Stephen A. Garrison, and Joseph A. Fiola
Chandler strawberries were planted on plastic mulch in September and renovated at various times after harvest during the next summer. Renovation treatments included mowing, thinning to three crowns/plant, and mowing plus thinning. These treatments were applied to 1-year-old and 2-year-old beds of `Chandler' strawberries. We conducted this study over two harvest seasons to compare winter conditions and the influence of polyester rowcovers. The second harvest season had severe winter temperatures (–5F), along with frequent ice accumulation. Marketable yields, culls, and fruit size were determined from each treatment. Yields varied with the time of treatment and with the degree of winter severity. Fruit size of renovated berries was smaller than first year berries, but still marketable. Polyester covers increased early yields.
Joseph A. Fiola, Robert Lengyen, and Harry J. Swartz
A major objective of the MD/NJ/VA/WI Cooperative Raspberry Breeding Program is to develop new primocane-fruiting raspberry cultivars that are early, with large fruit size, and good fresh flavor, relative to the `Heritage' standard. Step I seedling selections were made and tissue culture-propagated. The Step III advanced selection trial, planted in 1993, consisted of two advanced selections, JCR-F1 [Geo-1 (Autumn Bliss × Glen Moy) × Heritage–red], and JEF-B1 (Amity × Glen Eagles–golden), with a `Heritage' check. The planting was a RCB (four replications), with 3-m plots, 60-cm plant spacing, on raised beds with black plastic mulch (establishment year), and trickle irrigation. The 1994 season started dry, and mid-summer was warm and wet, inducing an early harvest overall. JCR-F1 was >2 weeks earlier, 40% higher yielding, with 18% larger fruit size than `Heritage'. JCR-F1 fruit was tall conic, cohesive, and had good flavor; plant vigor was very good. JEF-B1 was 10 days earlier than `Heritage', had 40% larger fruit size, but was 25% lower yielding; plant vigor was also good. The flavor was described as banana and apricot. The planting will be fruited for multiple seasons for continued comparison.