Effect of variety and some agrotechnical treatments on yield and quality of winter wheat (Triticum aestivum L.)

The aim of the presented paper was to evaluate the effect of four treatments and four nitrogen fertilization levels of stand on grain yield and quality of three winter wheat varieties. Field experiments were conducted in three consecutive growing seasons (1998-2001) at Borovce near Piešťany town (western part of the Slovak Republik) on loamy luvihaplic chernozem. Previous crop was lucerne. The experimental design consisted a split-split plot arrangement in a randomized complete block with four replications. Mains plots were treatments of stand, subplots N-fertilization and susbsubplots varieties. Harvest plot area 10 square m (8 x 1.25). Crop treatments: n.t. - non-treated control; H+GR+F - application of herbicide, growth regulator and fungicide; h+GR+F - harrowing and application of growth regulator and fungicide; h+F - harrowing and application of fungicide. At beginning of stem elongation (BBCH 30-36) 75 gramm of herbicide Granstar-75-DF (tribumeron methyl), 1.5 liter of growth regulator Retacel-Extra-R68 (chlormeuqat) and 0.5 liter of fungicide Alto-Combi-420-SC (carbendazin and cyproconazole) per hectare of experimental area in tank-mix form were applicated. Harrowing was realized at beginning of tillering (BBCH 20-23). Level and timing of N-fertilization: N0 - non-fertilized control (only phosphorus and potassium fertilization); N30 - nitrogen dose divided to two terms: 20 kg/ha at beginning of stem elongation (BBCH 30-36) and 10 kg/ha in heading (BBCH 51-59) (plus PK fertilization); N60 - nitrogen dose divided to four terms: 20 kg/ha at tillering (BBCH 20-29), 20 kg/ha at beginning of stem elongation (BBCH 30-36), 10 kg/ha in heading (BBCH 51-59) and 10 kg/ha at beginning of flowering (BBCH 61-65) (plus PK-fertilization); N90 - nitrogen dose divided to five terms: 20 kg/ha before sowing, then 20+20+15+15 kg/ha to the same terms as in N60 (plus PK-fertilization). Nitrogen was applied in form NH4NO3CaCO3. Doses of phosphorus and potassium were calculated according to content in the soil and to the grain yield of 7 t/ha. Characteristics of used varieties: Hana - early maturing, white ear with awnless, medium to good resistance against diseases, bread quality No 9, TKW (one-thousand kernel weight) is 44.1 g; Brea -medium early maturing, with some medium long awns in the upper third part of ear, medium to good resistance against diseases, bread quality No 8, TKW 45.7 g. Klea - medium early maturing, with occurrence of medium long awns in the upper third part of sar, medium to good resistance against diseases, bread quality No 7-8, TKW 42.5 g. Seed bed preparation consisted of stubble turning with disk tiller (120 mm) after the early third harvest of lucerne, mouldboard ploughing (220 mm) and harrowing (50-60 mm). The sowing rate was 450 of emerged kernels per square meter; by row spacing 125 mm. Experimental plots were harvested at full maturity. With except of grain yield were determined test grain weight, share of great kernels, protein content of grain in accordance with near infra-red reflectance (NIR) and values of sediment test (SDT) by Zeleny method. Varieties caused difference in every of analysed traits. Their effect on TKW value, grain protein content and share great kernels was stronger as experimental years influence. Nitrogen fertilization was not effective on grain yield, but increased protein content of grain and decreased values of TKW and share of great kernels. Complete chemical treatment of the stand (H+GR+F) increased grain yield but decreased the test weight, TKW and share of great kernels. On the other hand by harrowing of stand and fungicide use these values were increased however obtained grain yields were lower. Conditions of the experimental years modified varieties effect at every of analysed traits and treatments effect eventually fertilization on some ones.