Effects of diseases on the growth and yield of spring linseed (Linum usitatissimum), 1988–1998

Abstract

In spring linseed field experiments with fungicides at Rothamsted from 1988 to 1998, substantial yield losses associated with diseases occurred in three years and slight losses could be associated with diseases in other years. These yield losses were related to decreases in yield components (thousand grain weights and number of capsules). Leaf browning was observed each year and percentage leaf area with browning was the disease factor most consistently related to yield losses tin five years). Yield loss relationships for these five years suggested that for each 10% increase in percentage leaf area with browning there was a yield loss of 0.10 to 0.18 t ha(-1). Stem browning, lesions on capsules and powdery mildew were associated with yield losses in two years, three years and one year, respectively. Yield losses were greatest in years when the period of flowering and early capsule development in June and July was wetter than average, the predominant disease was grey mould (Botrytis cinerea) in wet years up to 1996, whereas pasmo (Mycosphaerella linicola) was most important in 1997 and 1998. Observed yield losses were small in hot, dry years when powdery mildew (Sphaerotheca lini) and verticillium (Verticillium dahliae) were the predominant diseases

Resistance of Some Flax Genotypes to Podwery Mildew and Effect of the Disease on Yield and Yield Components.

“…In India, Pandey and Misra (1993) reported that as the disease increased yield losses increased ranging from 11.8 to 38.9% and added that yield losses were greater when the disease appears earlier in the season. Perryan and Fitt (2000) reported a substantial yield loss in yield components of flax by powdery mildew disease. Ashry et al (2002) found that total length/plant was negatively correlated with each of disease incidence and disease severity, while straw yield/plant was negatively correlated only with the disease incidence.…”

Susceptibility of Some Flax Genotypes to Powdery Mildew and Effect of the Disease on Yield and Yield Components

“…(Ashry et al, 2002) found that total plant length was negatively correlated with each of the early and the late disease incidence, while straw yield per plant was negatively correlated only with the late disease incidence. (Perryan and Fitt, 2000) reported a substantial yield loss in flax due to the decrease in yield components by powdery mildew disease.…”

Factors affecting the development of Botrytis cinerea (grey mould) on linseed (Linum usitatissimum) buds, flowers and capsules

“…B. cinerea is an important pathogen of linseed (Linum usitatissimum L.) in the UK and can cause substantial yield losses (Fitt & Ferguson, 1993;Mercer et al, 1994). There is variation in the severity of epidemics on linseed, with wet, cool and humid conditions between flowering and harvest favouring infection and sporulation of B. cinerea (Fitt & Harold, 1995;Perryman & Fitt, 2000). In Northern Ireland in 1992, when rainfall in August was above average, flowers that failed to develop into capsules were almost invariably colonised by B. cinerea (Mercer et al, 1994).…”