Competitive Effects of Wild Oat in Flax

Abstract

Wild oat (Avena fatua L.) competition severely reduced flaxseed (Linum usitatissimum L.) yield. Averaged over two locations and two fertility levels, 80 wild oat plants/sq yd reduced the yield 9.4 bu/A (60.1%) in 1964 and 160 wild oat plants/sq yd reduced the yield 21.5 bu/A (82.1%) in 1965. At Fargo, 160 wild oat plants/sq yd reduced flaxseed yield 16.1 bu/A (86.1%) in 1966. Flaxseed yield components, including bolls/sq ft, seeds/boll, plants/sq ft, and weight/1000 flaxseed were determined. Although all components were reduced by wild oat competition, a reduction in the number of branches and flax bolls/sq ft accounted for 90.7% of the yield loss. A reduction in weight/1000 seed and the number of flax plants/sq ft contributed 7.0% and 4.6% to the yield loss, respectively. Competition from wild oat also reduced flaxseed quality. The percent oil was reduced in all 3 years of the experiment. Iodine number of the oil was reduced, primarily because of an increase in oleic acid and a decrease in linolenic acid.

A call for weed research in industrial hemp (Cannabis sativa L)

“…Sunflower production suffers from 58% to 99% weed infestation in some areas (Jurado‐Expósito et al ., ), and weeds have been shown to reduce kenaf yields by 40% in the Sudan (Fageiry, ) and 31.5–53.3% in Nigeria (Kuchinda et al ., ), while in the United States, cultivation increased kenaf yield and stem diameter (Burnside & Wiliams, ). Flax, another minor crop produced for fibre and oilseed, has a relatively poor competitive ability with weeds and suffers oilseed yield reductions of up to 82.1% (Bell & Nalewaja, ). In the absence of any peer‐reviewed research, it is not possible to estimate potential yield losses in hemp.…”

The Complex Genetic Architecture of Early Root and Shoot Traits in Flax Revealed by Genome-Wide Association Analyses

“…Unlike other crops such as canola, mustard and wheat that have aggressive root growth before early flowering the fastest root growth in flax is between early flowering to late flowering where it declines late bolling stage onwards (Liu et al, 2011). Under limited water, flax can be easily outcompeted by many weeds, exacerbating the competition for resources (Bell and Nalewaja, 1968; Gruenhagen and Nalewaja, 1969; Alessi and Power, 1970; Klimek-Kopyra et al, 2015). Flax is also less competitive than fibrous rooted cereals such as wheat (Morillon and Lassalles, 2002) that are with more extensive roots than flax in top soil layer (Gill, 1987).…”

Flax Response to Trifluralin

“…Flax free of weeds is essential to high flax seed yields and for quality straw for paper manufac turing. Flax competes poorly with weeds, and even low weed infestations cause severe yield losses (1,3).…”