PROXIMITY EFFECT OF SPRING CEREALS AND LEGUMES IN STRIP INTERCROPPING. PART IV. RESPONSE OF TRITICALE TO THE PROXIMITY OF WHEAT, BARLEY, PEA AND YELLOW LUPINE

Background. Because of its relatively low soil requirements and resistance to abiotic stress spring triticale is potentially a good component of mixtures (intercropping). The technologically easiest to use type of this agricultural method, i.e. mixed intercropping, despite having many advantages is not, unfortunately, gaining in importance due to problems related to crop protection and the variable composition of yield. An alternative is strip intercropping, which combines the advantages of pure sowing and intercropping. The production value of such cultivation depends on mutual interactions at the junction of neighbouring rows of different plant species. The aim of the undertaken experiments was to find out the response of spring triticale to the neighbouring occurrence of wheat, barley, pea and yellow lupine and to estimate the production effects of strip intercropping of triticale in the vicinity of plants of these species. Material and methods. This study uses the results of field experiments conducted as part of research on mixed sowings carried out in 2008–2010 in Mochełek near Bydgoszcz (53o13’ N; 17o51’ E). The experimental factor was the location of a plant row, within a strip, for the first four rows into the strip from the neighbouring species. The first row (contact row) was 12.5 cm away from the first row of the neighbouring species. The experimental unit was subsequent plant rows each four metres long. Results. Proximity of spring wheat, spring barley and pea was unfavourable for the growth and yield of spring triticale, especially in the row directly adjacent to a stand of the indicated species. The estimated reduction in triticale yield in strip intercropping, with three-meter wide strips in the two-sided neighbourhood of wheat, barley and pea, would amount to 2.67%, 4.85% and 4.36%, respectively. On the other hand, the proximity of yellow lupine resulted in a slight increase in the plant mass, including straw, the number of grains per spike and in grain yield, but only in the first row. The estimated increase in the yield of spring triticale grown in strip intercropping with yellow lupine, in 3-m-wide strips, was small and only amounted to 1.45%. Conclusion. The selection of plant species to neighbour with spring triticale in strip intercropping had a significant impact on the effect of spring triticale cultivation.