Production and accumulation potential of winter wheat (Triticum aestivum L.)

The aim of this work was to determine relationships between production and accumulation potential of winter wheat (Triticum aestivum L.) and their effect of yield creation. Treatment was carried out in 1995-1997 on the East-Slovakian Lowland in Milhostov (eastern part of the Slovak Republic) at Fluvi-Eutric Gleysol. From soil characteristics of treatment locality follow that this soil is characterised as clay-loam soil with content of clay particles more than 53% and has a weak pervious in whole profile. The top soil has lump aggregate structure with high bounding ability. High clay content in soil profile of Fluvi-Eutric Gleysol cause that soil is heavy tillage. The field treatment was realised without irrigation and two soil tillage technologies were examined: a - conventional tillage, i.e. current way of soil by ploughing into depth 0.24 m, b - no-tillage technology, i.e. direct sowing without tillage. On both soil tillage variants (variants repeated four times, plot area 30 square m) was applied 86 kg nitrogen (in form of ammonium sulphate), 19 kg phosphorus (in form of superphosphate) and 86 kg potassium (in form of potash). Application of mineral fertilizers was realised before sowing of winter wheat. Field bean was forecrop for winter wheat. Plant samples were taken during vegetation of winter wheat in five growth development phases as follows: DC 30 - start of shooting (7.4.1995 - 19.4.1996 - 18.4.1997), DC 37 - shooting (17.4.1995 - 28.4.1996 - 29.4.1997), DC 65 - flowering (10.6.1995 - 30.5.1996 - 29.5.1997), DC 71 - start of milk ripeness (18.6.1995 - 5.6.1996 - 10.6.1997), DC 75-77 - milk ripeness (26.6.1995 - 10.6.1996 - 15.6.1997). On taken samples were ascertained: - parameters of accumulation potential and hectare yield (amounts of plants, spikes and grains per square meter amount grains in spike, one-thousand kernel weight), - basic characteristics of production potential (LAI, CGR, NAR). The obtained data were tested by mathematics-statistical method. Simple and multiple regression analysis were used. The highest values of leaf area index LAI were ascertained in 1996 for both variants when were also the highest grain yields of winter wheat (7.79 t/ha for variant a, 6.87 t/ha for variant b. The highest values of crop growth rate (CGR) and net assimilation rate (NAR) were ascertained in phase of maximum increase of plant biomass. Maximum LAI values were determined in flowering and than to full ripeness decreased. The accumulation potential of winter wheat stand was characterised with average values as follows: 383 plants, 538.8 spikes and 14 971 grains per square meter, 27.77 grains in spike and one-thousand - kernel weight 43.15 g. The grain yield was about 0.74 t/ha higher on variant a (increase was statistically significant)