Leonard J. Eaton

Second cropping of wild blueberries — Effects of management practices

Wild blueberries (Vaccinium angustifolium Ait.) are normally managed on a biennial basis. Pruning forces the plant into a vegetative year without fruit, followed by the first crop year, which provides the greatest harvest. In subsequent years, harvest levels drop dramatically. Prior to the introduction of selective herbicides, second crop yields were too low to allow the adoption of a double harvest. This study was initiated to compare production and incomes of a single cropping (2-yr management cycle, the present system) versus a double cropping system (3-yr management cycle), using systems that include herbicides. Total yields and net incomes over the 12-yr study were affected by fertilizer applications, but not by management system (2-yr management cycle versus 3-yr management cycle) or pruning (burning versus mowing). Yields in second crop plots were lower than those in first crop plots, even though blossom numbers were higher. Fertilizer affected many aspects of blueberry plant development, including...

Gypsum—An Alternative to Chemical Fertilizers in Lowbush Blueberry Production

SUMMARY Five experimental trials were established in commercial lowbush blueberry (Vaccinium angustifolium Ait.) fields in eastern Canada and monitored over two cropping cycles to determine the value of gypsum as a soil amendment. Lowbush blueberry plants were treated each cropping cycle with either: (1) no application (control), (2) 10-10-10 fertilizer applied at 300 kg/ha (268 lb/acre), (3) gypsum applied at 4 t/ha (3572 lb/acre), or (4) the combination of (2) and (3). In the first cropping cycle, the application of gypsum and gypsum with fertilizer significantly increased tissue concentrations of N, P, K, Ca, Mn, and S in comparison to the control and fertilizer only treatments. Tissue K, Ca, Mn, and S were significantly increased in the second cropping cycle with gypsum application. Soil pH was reduced in the second cropping cycle with gypsum application. Gypsum with fertilizer increased stem length, live buds, total buds, and total blossoms in the first cropping cycle in comparison to the control. The treatments had no significant effect on marketable yield.

Nova Scotia Wild Blueberry Soil and Leaf Nutrient Ranges

Soil and leaf samples were collected from 44 wild blueberry fields throughout Nova Scotia in 1989–90 and in 1997–98, and analyzed for macro- and micronutrient content. Samples were obtained from sprout fields, in late July and early August, after terminal dieback of terminal leaf buds. Soil and tissue concentrations of P and K were increased by repeated fertilizer applications between the two sample periods, whereas soil pH was decreased. Leaf tissue concentrations of P, Cu, B, Zn and Fe were consistently lower than indicated by the Trevett standards, suggesting that a separate set of nutrient ranges should be adopted for Nova Scotia wild blueberry fields.

Honey bee stocking numbers and wild blueberry production in Nova Scotia

Eaton, L. J. and Nams, V. O. 2012. Honey bee stocking numbers and wild blueberry production in Nova Scotia. Can. J. Plant Sci. 92: 1305-1310. Wild blueberries (Vaccinium angustifolium Ait.) require cross pollination by insects. Introduction of managed species such as honey bees (Apis mellifera L.) and alfalfa leafcutting bees (Megachile rotundata Fabr.) is costly. We assessed the effects of stocking rates of honey bee hives and the interacting effects of the numbers of honey bees and other bees on yield of blueberries in commercial fields. Blueberry fields were sampled from 101 fields in years 1991 to 2010 in Nova Scotia. We recorded field size, numbers of beehives, yield, densities of bees, numbers of buds, blossoms and set fruit. Yields increased linearly with numbers of beehives, up to~4 hives/hectare, but at higher stocking rates there was too much variation to adequately determine the effects. Yields also increased linearly with numbers of honey bees, but there was an interaction with other bees that decreased the effects of honey bees, such that at maximum densities of other bees, there was no effect of honey bees on yield. These results suggest that other bees and honey bees compete for pollination. If producers have limited numbers of beehives, we suggest that more should be placed in areas where densities of other bees are lower, up to approximately 4 hives/hectare.

Efficient Mowing for Pruning Wild Blueberry Fields

SUMMARY Commercial wild blueberry (Vaccinium angustifolium Ait.) fields were mowed in spring and autumn at low (2.5-5 cm; 1-2 inches), medium (5-7.5 cm; 2-3 inches), and high (> 7.5 cm; > 3 inches) heights with a flail mower and also with a rotary mower (> 7.5 cm; > 3 inches), in order to determine optimal heights for mowing. Initial stem lengths reflected differences in mowing heights at both sites, but there were no differences in plant heights at the end of the pruning year growth, or in the spring of the crop year. There were no differences in buds per stem or in fresh fruit yields among the treatments at the Adams field, or among the flail mowed plots at the Murray Siding field. Yields in rotary mowed plots were lower than yields in all other plots at the Murray Siding field, and also stems were more branched than were stems in the other treatment plots. These results suggest that producers can mow their fields at higher heights without impact on plant growth and production, as long as they use the flail mower. Mowing at greater heights results in less damage to equipment, plants and soil, and is more economical than the low heights of mowing presently recommended for the industry.

Effects of deicing salt on lowbush blueberry flowering and yield

The effects of deicing salt (NaCl) on buds, blossoms and yields of lowbush blueberry (Vaccinium angustifolium Ait.) were assessed over 3 yr in two commercial fields adjacent to a major Nova Scotia highway. Concentrations of road salt on exposed stems were highest next to the highway, and decreased with distance from the road. Numbers of blossoms, and subsequent fruit yields were low nearest the road, and increased with distance from the highway. Numbers of live blueberry buds and blossoms, and subsequent yields, were inversely related to concentrations of road salt on the stems. Plants under plastic shelters placed near the highway had more live buds and blossoms, as well as higher yields relative to plants exposed to deicing salt. Key words: Vaccinium, sodium chloride, salt damage, desiccation

Comparison of consecutive and alternate fertilizer applications in wild blueberry production

Research has shown that improved nutrient uptake and yield of wild blueberries (Vaccinium angustifolium Ait) are very sporadic when fertilizers are applied. Growers are concerned with environment impacts and keeping fertilizer costs to a minimum. Two experiments were conducted to evaluate the response of wild blueberries to soil-applied fertilization over four cropping cycles in Prince Edward Island and Nova Scotia from 1997 to 2004. Commercial fertilizers (17-17-17, 1-46-0 and 13-26-5) were soil-applied in the sprout year either as a consecutive fertilizer application (every cropping cycle) or an alternate fertilizer application (every second cropping cycle). All fertilizers were applied at a rate of 200 kg ha-1. Fertilizer applications increased soil levels of P and K, leaf tissue concentrations of N and P and stem lengths of plants. Higher levels of soil P and leaf tissue concentrations of N, P and K were observed with consecutive than with alternate fertilizer applications. Average stem lengths, buds ...

Maritime Provinces Wild Blueberry Fertilizer Study

ABSTRACT Field experiments were carried out over a 4-year period (2001–2004) at one commercial site in each of the Maritime Provinces, Prince Edward Island, Nova Scotia, and New Brunswick. The study was designed to determine the effects of applied fertilizer in sprout year only and in both sprout and crop year on leaf and soil concentration, plant development, and yield. Individually, sprout-year applications of fertilizers ammonium sulfate, di-ammonium sulfate, and 17-17-17 and crop-year application of ammonium sulfate did not affect soil and leaf concentrations, plant growth, or yield. When comparing the mean of fertilizer applications to unfertilized plots, levels of soil, P, K, and S were increased and soil pH decreased and leaf tissue concentrations of N, P, K, and S were increased. Stem length, number of live buds, and number of blossoms were increased; however, yield was not affected in the first cropping cycle and was lowered in the second cropping cycle by applications of fertilizers. Crop-year applications of ammonium sulfate provided no benefit to wild blueberry production.

Spring frost damage to placental tissues in lowbush blueberry flower buds

Closed flower buds and flowers at full bloom of Vaccinium angustifolium Ait. were collected from the field and histologically examined after severe spring frosts. Prior to anthesis, blackened ovarian placentae in closed buds were the only damaged tissues evident; placental damage may interfere with both seed and fruit set. Undetected frost damaged placentae may contribute to losses in commercial yield. Key words: Vaccinium, frost damage, placenta

Effects of Salt Deposition from Salt Water Spray on Lowbush Blueberry Shoots

SUMMARY Many commercial lowbush blueberry (Vaccinium angustifolium Ait.) fields border the Bay of Fundy and the Gulf of St. Lawrence. Qualitative producer observations in these areas indicate that salt spray from the marine environment during winter months reduces yield of the lowbush blueberry. To quantitatively examine the effects of ocean spray on the lowbush blueberry, the amount of salt deposited on stems of this species was assessed at several commercial sites in the Canadian provinces of Prince Edward Island and Nova Scotia between 1998 and 2000. Randomly selected areas of commercial fields were protected with 1.8 m × 0.45 m (5.9 ft × 1.48 ft) shelters covered with 4 mil plastic film. Data on growth, yield, and salt deposition on shoots were recorded from both protected and exposed plants. Results varied according to location, weather conditions, and snow cover. Tree line wind protection and snow cover appeared to reduce the severity of salt spray-induced damage to the lowbush blueberry. In general, the exposed plants exhibited more salt deposition (mg g−1 dry weight of stems), more dead buds, fewer blossoms and lower yields in comparison to covered specimens.