Wpływ sposobu uprawy roli i intensywności pielęgnowania roślin na zachwaszczenie łanu pszenicy ozimej

polonais. The aim of the study was determine the influence of three reduced tillage methods in comparison with conventional tillage and different intensity of canopy care on weed infestation of winter wheat. The field experiment was carried out on lessive soil in the years 1994-1997. The experimental factors were four methods of soil tillage and four methods of crop canopy care. The tested cereal was winter wheat (Cobra cultivar) growing after winter rape. Tillage treatments: I. traditional (stubble ploughing + harrow, presowing ploughing 20-22 cm deep + harrow); II. reduced tillage (pre-sowing ploughing shallow to 10-12 cm deep); III. reduced tillage (only pre-sowing ploughing to 20-22 cm deep was performed); IV. reduced tillage (disking and cultivating with cultivator). Care method: A - without care operations; B - spring harrowing only; C - spring harrowing and herbicide application (Arelon Dysp. 500 S.C., Aminopielik D or Chwastox DF); D – spring harrowing, herbicide application (as above) and fungicides (Tilt 250 EC, Bayleton 25 WP). The results revealed that, in comparison to traditional tillage system (I), all reduced tillage treatments (II, III, IV) caused increased weed infestation of the canopy. However, weed density and air-dry weight per unit area were significantly higher only after IV tillage treatment (ploughless tillage) was applied. The herbicides significantly limited canopy weed infestation. Density and air-dry weight of weeds substantially decreased only under herbicide treatments. Spring harrowing operation as well as fungicide treatment contributed little to weed infesttation of winter wheat canopy in comparison to object (A). Apera spica-venti (L.) P. BEAUV., Stellaria media (L.) VILL., Myosotis arvensis L. (HILL), Capsella bursa-pastoris L., and Agropyron repens (L.) P. BEAEUV were the dominant species on all experimental objects. In spite of that, Matricaria maritima ssp. inodora (L.) DOSTAL was abundant on herbicide plots.