EFFECT OF SOWING TIME AND SEED RATE ON THE PRODUCTIVITY OF WINTER WHEAT (TRITICUM AESTIVUM L.)

Abstract

The main objective of the study was to determine the effect of sowing time and seed rate on the productivity of the common wheat crop. The experiment was carried out at the Experimental Station of the Academy of Agriculture of Vytautas Magnus University from 2022 to 2023. The two-factorial experiment investigated the effect of sowing time and seed rate on the productivity of winter wheat. Soil granulometric composition - medium loam. In 2021, agrochemical analyses of the topsoil showed that the topsoil had a neutral reaction (pH – 7.0), medium humus content (2.05 %), very high phosphorus content (241 mg kg^-1) and high lime content (186 mg kg^-1). The winter wheat variety 'Skagen' was grown in the experiment. The precursor was winter oilseed rape. The experiment was carried out in 6 replications. The total plot size was 40 m² and the reference plot size was 20 m². The winter wheat was fertilised with ammonium nitrate three times: on 28 March - N₅₆ , on 13 April - N₆₈ and on 2 May - N₄₀. The significantly densest pre-harvest crop was found in the winter wheat plots sown on 6 and 27 September at seed rates of 5 million units ha^-1 (672 and 678 units m^-2 respectively) and on 13 September at seed rate of 3.0 million units ha^-1 (600 units m^-2), as compared with those sown at the other sowing dates and at the full seed rates. In the late sowing (27 September), there is a tendency for the density of the crop to decrease from 678 to 424 units m^-2 as a result of the reduction in seed rate. Significantly fewer stems were found in the 3 and 2 million units ha^-1 seed rate crops. The highest weight per 1000 grains (54.2 g) was found in winter wheat fields sown on 20 September at a seed rate of 3 million pieces ha^-1. The significantly lowest 1000-grain weight (44.2 and 45.5 g) was found in winter wheat sown on 27 September at a seed rate of 4 and 3 million pieces ha^-1. The significantly highest yields of winter wheat (10.0 and 9.8 t ha^-1 ) were obtained after sowing on 20 September at a seed rate of 4 and 2 million pieces ha^-1 and on 27 September at a seed rate of 4 million pieces ha^-1. The lowest yields (8.1 and 7.7 t ha^-1) were recorded for winter wheat sown on 6 and 27 September in the fields sown at a seed rate of 2 million pieces ha^-1.