Identification of Powdery Mildew Resistance Genes in Selections from Moroccan Barley Landraces

Abstract

The formation of yield in two different combinations: vetch with wheat or oats, and the effect of vetch on yield potential of cereals has been investigated in Estonian field experiments over three years. We found that the inclusion of vetch seed in cereal seed and increase of its seed density led to considerable decrease in the yield of the cereal component (R=0.980–0.998). The adverse effect of vetch on cereal yield led to a reduction in wheat yield by up to 1861?kg?ha^?1 on average for the three years, and in oats yield by up to 1413?kg?ha^?1. One reason for the decreases in cereal yields was the formation of smaller grains in cereals under increased vetch seed densities. As a three-year average, the wheat 1000-seed weight decreased by up to 6.3 g while the corresponding figure for oats under identical conditions was 2.5 g. The inclusion of vetch in a crop and the increase of its seed density led to a substantial increase in the protein content of cereal grains. In oats, the change in grain protein content was smaller. At the same time, the maximum protein yield per area unit in cereals was obtained from their monocultures. In a mix with vetch, the amounts of nitrogen consumed by cereals decreased and protein yield of cereals per area unit reduced at higher vetch seed densities. Vetch-cereal mixes had an advantage over cereal monocultures as far as protein yield was concerned. In vetch-wheat and vetch-oats mixes the maximum protein yield was 500?kg?ha^?1 and 438?kg?ha^?1, respectively, on average for the three years. Of the two combinations, vetch-oats mixed crop gave the highest yield of grain, whereas the higher mixed crop yield resulted from the oats component. Oats is somewhat more competitive with vetch than wheat. Vetch-wheat mixed crop gave the highest protein yield because the protein content of wheat grains was higher than oat grains. Legume-cereal mixes are particularly suited for the conditions of organic farming as they ensure a relatively good harvest and a high protein yield.