STRAWBERRY VARIETY EVALUATIONS
(adapted from David Handley, University of Maine Extension)
Twelve strawberry varieties were planted in small plots in a narrow matted row system in 1999. Establishment of beds during the planting year was poor, due to drought conditions. Problems with plant vigor persisted into the second year. Dry conditions at the end of the 2000 season again limited runner establishment so the beds did not re-establish well after renovation. As a result, some of the varieties had relatively low plant populations this spring. Yields were generally lower than the first picking year, which is typical for this production system, but an infestation of cyclamen mites also played a role in the lower yield.
Mesabe, Mira and Cavendish (all mid-season ripening) were again among the top producing varieties in the 2001 season. Jewel also preformed well and maintained its high yield better than most other varieties over the two seasons. Yields of Brunswick, a very good performer in 2000, fell considerably this year, although fruit quality was still very good. Sable was again a good producer for an early variety, with good fruit quality. The other early varieties, Evangeline, Northeaster and Mohawk were again relatively low yielding, although Evangeline and Mohawk had good flavor. Cabot was intermediate for yield, and once again had the largest fruit size of any variety in this trial. Jewel, Cavendish and Brunswick also had very good fruit size. Honeoye and Winona improved a bit in their relative standings this year, but yields were still low. In the case of Honeoye, this is likely due to the poor condition of the crowns in the planting year. In past trials Honeoye has been a good producer of large, attractive fruit.
Based on the two years of data collected from this trail, Mira, Mesabe,
Cavendish and Jewel appear to be the best overall performing varieties.
These are all mid- and mid-late season ripening. Sable is a promising
early variety, and Cabot offers very large fruit size and late ripening,
perhaps best suited for a specialty market.
VARIETY LBS/ACRE GRAMS/BERRY LBS/ACRE GRAMS/BERRY
Mira 10,436 10.5 15,676 9.4
Mesabe 8,992 9.3 16,406 11.2
Jewel 8,173 12.1 11,195 12.1
Cavendish 7,247 11.5 13,471 14.0
Sable 6,925 9.7 12,327 10.4
Brunswick 5,882 11.4 15,854 12.4
Honeoye 4,826 10.8 6,305 11.4
Winona 4,065 10.7 5,837 10.5
Evangeline 3,361 8.6 7,846 10.0
Cabot 3,092 16.9 10,008 20.7
Northeaster 2,952 10.1 6,441 11.5
Mohawk 2,059 9.1 9,681 12.3
(Note: acreage yield was extrapolated from small plot data. Yields can
vary greatly from site to site. These numbers may not reflect actual performance
obtained in grower fields.)
RED RASPBERRY VARIETY UPDATE
(by David Handley, University of Maine Extension)
There have been numerous introductions of new raspberry varieties in
recent years, but only a few are likely to withstand the growing conditions
of northern New England. Although not all of the varieties listed below
are "new", here is a review of some of the more recent introductions.
Summer bearing varieties:
Encore: Recent release form New York. Ripens late season, with long harvest season. Hardy and free suckering with vigorous, erect, nearly spineless canes. Fruit are medium-large and firm with good flavor. Encore shows a moderate tolerance to Phytophthora root rot.
K-81-6: From Nova Scotia. Ripens mid-late season, very hardy. Vigorous, tall canes. Medium-large, bright red fruit with good flavor.
Lauren: A recent release from Maryland. Mid-late season ripening, only
moderate hardiness. Tall, vigorous canes that will be injured under fluctuating
winter temperatures. Fruit are very large and fairly firm with fair flavor.
Reveille: From Maryland. Early ripening, fairly hardy. Vigorous, productive canes that sucker freely. Large fruit with good quality, but soft.
Ever bearing (primocane fruiting) varieties:
Autumn Britten: Recently released from East Malling, Scotland, similar to Autumn Bliss. Early ripening primocane crop. Limited cane production, close planting recommended. Medium to large fruit with very good quality.
Caroline: A recent release from Maryland. Mid-early ripening primocane crop. Vigorous with tall canes. Large, firm fruit. Ripens over a long harvest season. Moderately hardy for floricane crop.
Dinkum: From Australia. Similar to Autumn Bliss, early ripening primocane crop on moderately vigorous canes. Large, firm flavorful fruit.
Polana: From Poland. Early ripening primocane crop. Short canes, but vigorous growth. High yield potential, medium sized fruit, with a high percentage of "doubles" making harvest difficult. Good flavor.
Prelude: A recent release from New York. Although everbearing, this variety is primarily grown for its very early ripening floricane (second year) crop. Plants are vigorous and sucker freely. Medium-sized fruit, dark red, good quality. Primocane crop ripens late.
Anne: A recent release from Maryland. Mid to late season primocane crop. Vigorous, tall canes. Medium to large light yellow fruit, variable quality.
Goldie: Yellow sport of Heritage and similar in ripening season, productivity and growth habit. Fruit actually are more of a pink color when ripe and are prone to sun bleaching.
In summary, some or all of these varieties may be worth testing in your site if there is adequate winter protection for the more tender selections (e.g. Lauren), and you have a market for larger-sized fruit or fruit which ripen a little earlier (Prelude) or later (Encore, everbearing types). Compare the performance of these with the standard varieties presently grown in New England such as Boyne, Killarney, Nova and August Red.
WINTER MULCH FOR STRAWBERRIES
(adapted from Patrick Byers, University of Missouri)
The key to consistent strawberry production in cold climates is mulching. Research has shown that the crowns of non-mulched straw-berry plants can suffer damage after winter temperatures below 12?F. Unprotected strawberry plants are also vulnerable to desiccation damage from drying winter winds. The disease black root rot is more severe in non-mulched plantings.
Winter mulch protects plants from severe cold. Desiccation is a problem, especially after winter temperature fluctuations, and mulch will protect plants from drying out. Mulches also protect plants from injury caused by soil heaving, which results from freezing/ thawing cycles.
When should the strawberry grower plan to apply mulch? Research suggests that a good guide is to apply mulch after 3 consecutive days with a soil temperature of 40?F. This soil temperature usually occurs after several frosts, and the plants have slowed growth in response to cooler temperatures. Apply mulches before the soil freezes. In Vermont, mulches are usually applied in late November.
Production systems for strawberries are undergoing changes that affect mulching. Plants on raised beds, for example, are more vulnerable to cold injury than plants in level plantings. Annual production systems, such as fall planted plasticulture, may utilize less hardy or disease susceptible cultivars. Mulching practices must adapt to these new systems.
The traditional mulching material for strawberries is straw. Straws from wheat, rice, oats, or Sudan grass work well. Straws coarser than Sudan grass are not recommended. A good straw source will deliver straw that is clean, free from weed seed, and contains a minimum of grain seed. Strawberry growers can produce their own mulch, often cutting the straw before the grain seed is viable. Store straw for mulching in a dry area. Occasionally grain seedlings can become a weed problem the following spring; an application of sethoxydim will give good control.
A traditional level matted row planting will require 2.5 to3 tons of straw per acre for a 2 to3 inch deep mulch. This equates to about 300 small bales of average weight. Raised bed plantings may require twice this amount for adequate coverage. Plasticulture plantings of cultivars such as Chandler are usually not mulched with straw.
Floating row covers are useful for winter protection of strawberry plantings. Only the heavier weights are recommended for winter protection. At present a widely available weight recommended for winter strawberry protection is 1.25 oz/yd 2 (42 g/m 2 ), which costs about 4 cents per square foot. With proper care, this heavier fabric should last 3 to 4 seasons. Floating row covers are widely used to protect annual plasticulture plantings. Row covers are best applied on still days. Be sure to line up sufficient labor to place the row cover. If possible, use wider widths for more efficient application. The row cover edges must be anchored, as must areas where two covers overlap. Edges may be anchored with posts, rocks, or tube sand. The edges may also be covered with soil.
Once the mulch is in place, the job is not done for the winter. Monitor the planting frequently. If straw has blown off areas, replace at once. Watch the edges of row covers, and adjust anchors if needed. Repair any rips or holes as soon as possible.
POTATO PROGRAM PLANNED FOR MARCH 6
University of Maine Extension potato experts have generously offered to put on a program for VT and NH growers in the White River Junction area on March 6th or 7th - Details are in the works. Please contact me if you have suggestions for specific topics you’d like covered.
NEED A VEGETABLE AND BERRY CONFERENCE PROGRAM?
If you are a commercial vegetable or berry grower in Vermont, you should have received a copy of the program for the Dec. 11-13 New England Vegetable and Berry Conference and Trade Show. Anyone that needs a copy please call the Brattleboro Extension office (802) 257-7967.