The Impacts of Fertilizer and Hexazinone on Sheep Sorrel (Rumex acetosella) Growth Patterns in Lowbush Blueberry Fields

Abstract

Sheep sorrel is an invasive, creeping perennial weed of lowbush blueberry fields that decreases yields and hinders harvest. Much of the basic phenology of sheep sorrel in blueberry fields is unknown and not documented in peer-reviewed journals. Three levels of fertilizer (0, 20, and 40 kg N ha−1) and two levels of hexazinone (0 and 1.92 kg ai ha−1) were applied to three vegetative-year blueberry fields to determine their effects on root and shoot growth, biomass allocation, and seed production of sheep sorrel plants. Hexazinone efficacy varied widely between sites, but suppressed shoot biomass, achene number and weight, and reproductive biomass, as well as the reproductive : shoot biomass ratio. Fertilizer tended to increase achene number and increased sheep sorrel shoot biomass in the absence of hexazinone, but had no effect on achene weight, root biomass, or reproductive biomass. When fertilizer was applied, sheep sorrel allocated resources to sexual reproduction at the expense of vegetative growth.

Weed seed granivory by carabid beetles and crickets for biological control of weeds in commercial lowbush blueberry fields

“…We suspect that these insect species contribute to seed consumption in the field, although further studies are required to determine whether this can result in effective weed suppression because seed consumption rates relative to seed production are unknown. For example, female sheep sorrel plants produce 177-270 seeds (achenes) per flowering shoot in lowbush blueberry fields in Nova Scotia (Kennedy et al, 2011) with 222-725 shoots/m 2 (White et al, 2014). Moreover, established populations tend to be maintained predominantly by vegetative reproduction of shoots from the creeping root system (White et al, 2014), and so it is unclear whether granivory is practically significant.…”

Weed community composition after 43 years of long-term fertilization in tropical rice–rice system

“…Many arable weed species plays a key role in supporting biodiversity within agro-ecosystems (Marshall et al, 2003;Fried et al, 2009) because they often constitute the base of the food chain for herbivores and their natural enemies, supporting many species of beneficial insects, especially crop pollinators (Rypstra et al, 1999). In crop fields, weeds compete with crops for most abiotic resources such as nutrients, light and water, and their presence usually results in drastic declines in crop yield and quality (Vollmann et al, 2010;Kennedy et al, 2011;Tang et al, 2013). Weeds are notorious yield reducers, and as such are, in many situations, economically more important than insects, fungi, or other pest organisms (Savary et al, 1997).…”

Pre- and post-vernalization ramet removal reduces flowering of red sorrel (Rumex acetosellaL.) in wild blueberry (Vaccinium angustifoliumAit.)

“…The plant is dioecous and spreads by seeds and a shallow creeping root system (Kennedy 2009;White 2014). Seedlings contribute to established red sorrel populations in wild blueberry fields ), but vegetative reproduction of ramets from the creeping root system is the primary means of population maintenance (Kennedy 2009;White et al 2014).…”

“…The plant is dioecous and spreads by seeds and a shallow creeping root system (Kennedy 2009;White 2014). Seedlings contribute to established red sorrel populations in wild blueberry fields ), but vegetative reproduction of ramets from the creeping root system is the primary means of population maintenance (Kennedy 2009;White et al 2014). The majority of red sorrel ramets remain as vegetative rosettes persisting below the blueberry canopy in the year of emergence, as flowering occurs primarily in overwintering ramets and is induced by vernalization and subsequent exposure to long days (White et al 2015).…”

“…Flowering ramets bolt and grow taller than established blueberry stems, hindering harvest operations in heavily infested fields. These ramets also produce abundant seeds (Kennedy et al 2011), which are a frequent contaminant on harvesters (Boyd and White 2009), and produce pollen that may contribute to increased incidence of Botrytis cinerea infestations in bearing-year fields (Hughes 2012).…”