Herbicidal weed control and crop-year NPK fertilization improves lowbush blueberry (<i>Vaccinium angustifolium</i> Ait.) production

Eaton, L. J. and Nams, V. O. 2006. Second cropping of wild blueberries -Effects of management practices. Can. J. Plant Sci. 86: 1189-1195. 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 stem length, numbers of buds and blossoms, and fruit yields. Over time, yields and net incomes in the 3-yr management cycle were similar to those for the standard 2-yr management cycle. L'élagage plonge la plante dans un état végétatif pendant une année durant laquelle elle ne donne pas de fruits. L'année suivante se caractérise par la récolte la plus abondante. Ensuite, le nombre de fruits baisse de manière draconienne. Avant l'arrivée des herbicides sélectifs, le rendement de la troisième année était trop faible pour qu'on songe à adopter un système de double récolte. Les auteurs ont entrepris une étude afin de comparer la production et le revenu venant d'un régime à récolte unique (cycle de deux ans, comme c'est le cas présentement) à ceux d'un régime à double récolte (cycle de trois ans) recourant aux herbicides. Le rendement global et le revenu net relevés lors de cette étude de 12 ans ont été affectés par les applications d'engrais, mais pas par le système cultural (cycle de deux ans contre cycle de trois ans) ni par l'élagage (brûlis contre tonte). Le rendement des parcelles de trois ans était plus faible que celui des parcelles de deux ans, malgré une floraison plus abondante. La fertilisation affecte maints aspects du développement de la plante, notamment la longueur des tiges, le nombre de bourgeons et de fleurs, et le rendement fruitier. Avec le temps, le rendement et le revenu net issus du cycle de trois ans se rapprochent de ceux observés pour le cycle de deux ans.

Section: Discussionmentioning

confidence: 77%

Second cropping of wild blueberries — Effects of management practices

Eaton¹,

Nams²

2006

“…The current trial was established on the plots of a previous experiment (Penney and McRae 2000) conducted between 1983 and 1991 at the Atlantic Cool Climate Crop Research Centre's Blueberry Substation in Avondale, Newfoundland and Labrador (lat. 47°25′N; long.…”

Section: Experimental Design and Field Managementmentioning

confidence: 99%

“…Some negative responses were reported to be due to the stimulation of weeds by the applied fertilizer (Chandler 1943;Smagula and Ismail 1981). Recent research by Penney and McRae (2000) indicates that a lack of response to fertilizer may be related to timing of application. They showed that fertilizer applied in the vegetative year did not increase yield, but when applied in the crop year, increased production by approximately 40% over that with weed control alone.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Second-crop N fertilization improves lowbush blueberry (Vaccinium angustifolium Ait.) production

Penney¹,

McRae²,

Bishop³

2003

Self Cite

. 2003. Second-crop N fertilization improves lowbush blueberry (Vaccinium angustifolium Ait.) production. Can. J. Plant Sci. 83: 149-155. Most commercial blueberry growers follow a 2-yr pruning cycle because second-crop yield in a 3-yr cycle is usually too low for an economical harvest. Research was conducted to determine the extent to which second-crop production could be increased by applying fertilizer in the second-crop year. Treatments, consisting of factorial combinations of N (0, 60 kg ha -1 ), P (0, 26 kg ha -1 ), and K (0, 50 kg ha -1 ), were studied over two 3-yr burn-pruning cycles on a natural lowbush blueberry stand. Treatments were applied prior to, or shortly after, flower buds started to swell in the spring of the second-crop year. Nitrogen increased ripe fruit yield by 65% (3410 vs. 2070 kg ha -1 ) when compared with plots not previously fertilized with N, and by 43% (3410 vs. 2380 kg ha -1 ) when compared with plots previously fertilized with N. These results indicate that N might make the second crop economical to harvest. Phosphorus did not significantly affect yield, but K applied in combination with N in the second-crop year negatively affected production and Mg uptake. The increase in yield by N was due to more ripe berries resulting from a higher total (ripe + unripe) number of berries and hastened maturity that increased the percentage of ripe fruit. Reduced fruit abortion is suspected to be the reason for higher berry numbers. In contrast, the negative response to K applications with N was due to reduced total berry numbers. La majorité des producteurs commerciaux de bleuets taillent les arbustes aux deux ans, parce que, sur un cycle triennal, la production est habituellement trop faible pour être rentable la deuxième année. Les auteurs ont effectué des recherches pour déterminer dans quelle mesure l'application d'un engrais la deuxième année augmenterait la production. Les amendements consistaient en un mélange factoriel de N (0 et 60 kg par hectare), de P (0 et 26 kg par hectare) et de K (0 et 50 kg par hectare) et ont été étudiés pendant deux cycles triennal de brûlis-élagage, sur un peuplement naturel de bleuets nains. Les traitements ont été appliqués avant le gonflement des bourgeons floraux au printemps de la deuxième année, ou peu après. L'azote augmente le rendement en fruits mûrs de 65 % (3 410 kg par hectare contre 2 070), comparativement aux parcelles qui n'avaient jamais reçu d'engrais azoté, et de 43 % (3 410 kg par hectare contre 2 380), comparativement à celles bonifiées antérieurement. Ces résultats indiquent que l'azote pourrait rentabiliser la récolte la deuxième année. Le phosphore ne modifie pas le rendement de manière sensible, mais le potassium a une incidence néfaste sur la production et l'absorption de magnésium, quand il accompagne l'azote la deuxième année. L'accroissement du rendement résul-tant de l'amendement azoté s'explique par la plus grande proportion de baies mûres récoltées (sur le total de fruits mûrs et verts) et par la plus grande précocité, qui a ...

“…), Solidago spp. and Veronica officinalis L. (Rayment 1965;Penney and McRae 2000). Many of these species may also be found in blueberry fields in Nova Scotia (McCully et al 1991), New Brunswick (Hall 1955(Hall , 1959, and Quebec (Bouchard 1986;Lapointe and Rochefort 2001).…”

mentioning

confidence: 99%

Effect of long-term burn-pruning on the flora in a lowbush blueberry (Vaccinium angustifolium Ait.) stand

Penney¹,

McRae²,

Rayment³

2008

Self Cite

. 2008. Effect of long-term burn-pruning on the flora in a lowbush blueberry (Vaccinium angustifolium Ait.) stand. Can. J. Plant Sci. 88: 351Á362. The effect of burn-pruning on the flora in a natural stand of lowbush blueberry was studied over a 24-yr period in Newfoundland and Labrador, Canada. Treatments were: not burned and burn-pruned every 2nd, 3rd, or 4th year. A vegetative survey was conducted before burning and periodically in succeeding years. Following statistical analyses, species were grouped according to their response to burning, as follows: those not significantly affected; those eliminated or whose frequency of occurrence was reduced; and those whose occurrence was increased. Initially, burning virtually eliminated Juniperus communis var. depressa, Empetrum nigrum, Cladina rangiferina, Lycopodium clavatum and Pleurozium schreberi, reduced the frequency of occurrence of nine species by 6 to 69%, and increased 13 others by 1 to 2050%. With burning, Polytrichum commune and Fragaria virginiana ssp. glauca, in particular, increased very early in the study to become two of the most prevalent species. Also, except for some initial effects of burning, the lowbush blueberry and some initially prevalent species (Festuca filiformis, Maianthemum canadense, Danthonia spicata, Cornus canadensis and Luzula multiflora var. acadiensis) remained among the most dominant species. Of the species studied, only seven each of those increased or decreased by burning were affected by the burnpruning cycle. In both groups, the greatest increases or decreases in the frequency of occurrence were obtained with the 2-yr burn-pruning cycle. Ils ont groupe´les espe`ces comme suit, selon leur re´action au traitement en recourant a`des me´thodes d'analyse statistique : plantes peu touche´es; plantes supprime´es ou moins abondantes; plantes plus abondantes. Au de´part, les bruˆlis ont virtuellement e´limine´Juniperus communis var. depressa, Empetrum nigrum, Cladina rangiferina, Lycopodium clavatum et Pleurozium schreberi, diminue´la fre´quence de neuf autres espe`ces de 6 a`69 % et accru l'abondance de 13 autres de 1 a`2 050 %. Apre`s les bruˆlis, Polytrichum commune et Fragaria virginiana ssp. glauca ont vu leur population augmenter tre`s rapidement au de´but de l'e´tude pour devenir deux des espe`ces les plus courantes. Outre certains effets initiaux attribuables aux bruˆlis, le bleuet nain et quelques espe`ces de´ja`abondantes (Festuca filiformis, Maianthemum canadense, Danthonia spicata, Cornus canadensis et Luzula multiflora var. acadiensis) ont continue´de figurer parmi les espe`ces dominantes. Sur les espe`ces examine´es, sept seulement des groupes dont les bruˆlis accroissaient ou re´duisaient la population ont e´te´affecte´es par le cycle d'e´lagage et de bruˆlis. Dans ces deux groupes, la plus forte hausse ou baisse d'abondance se produit avec le cycle d'e´lagage-bruˆlis de deux ans.