Protection of Fibre Flax Crop Against Flea Beetles and Seedling Blight Using Compound Seed-Dressers

Abstract

The trial was carried out at Upyte Research Station of the Lithuanian Institute of Agriculture during the period 1999–2001, where flax (Linum usitatissimum L.) cv. ‘Baltuciai’ had been grown. The effect of compound seed-dressers RAPCOL FDL 323 CS (active ingredients: insecticide phurathiocarb 300 g l⁻¹ + fungicide metalaxil 20 g l⁻¹ + fungicide fludioxonil 3 g l⁻¹) (3000 ml 100 kg flaxseed⁻¹) and CRUISER OSR 321.3 FS (active ingredients: insecticide tiametoxam 280 g l⁻¹ + fungicide metalaxil-M 33.3 g l⁻¹ + fungicide fludioxonil 8 g l⁻¹) (dose rates 100, 250, 500, 750 and 1000 ml 100 kg flaxseed⁻¹) on the occurrence of flea beetles and seedling blight in flax crop when compared to the effect of seed-dresser Vitavax FF 200 (active ingredients: carboxine 200 g l⁻¹ + thiram 200 g l⁻¹) and insecticide Fastac 10 EC (active ingredient: alphacypermethrin 100 g l⁻¹) has been investigated.

The experimental findings suggest that 49.0 to 90.5% of flax plants were affected by flea beetles (Aphthona euphorbiaeSchr., Longitarsus parvulusPayk.) annually in the plots sown with untreated seed. Significantly fewer affected plants were identified in the plots sown with the seed treated with phurathiocarb 900 g + metalaxil 60 g + fludioxonil 6 g 100 kg⁻¹ seed (Rapcol, 3 l100 kg flaxseed⁻¹) and tiametoxam 28 g + metalaxil-M 3.33 g + fludioxonil 0.8 g 100 kg⁻¹ seed or tiametoxam 70 g + metalaxil-M 8.325 g + fludioxonil 2 g 100 kg⁻¹ seed (Cruiser,100 ml or 250 ml 100 kg⁻¹). Tiametoxam + metalaxil-M + fludioxonil, applied at higher dose rates (Cruiser, 500–1000 ml 100 kg⁻¹) gave a higher efficacy. The incidence of seedling blight (Colletotrichum lini (Westerdijk) Tochinai) was lower in the plots sown with the seed treated with compound seed-dressers. The impact of compound seed-dressers was noticed even at the flax 4–6 pairs of leaves stage.

Key Words:

• Compound seed-dressers
• fibre flax
• flea beetles
• seedling blight