The epidemic of wheat stem rust (Puccinia graminis tritici) on spring wheat in South-West Finland in 1951, primarily from the breeder’s point of view

Erkki I Kivi

doi:10.23986/afsci.71395

Abstract

The paper reports on the black stem rust epidemic in South-West Finland in summer 1951, primarily from a plant breeder’s point of view. The report is based on the material collected by the Agricultural Research Centre, Department of Plant Breeding, from the spring wheat cultivations of South-West Finland and the Department’s trial field at Jokioinen. 1. Black stem rust was quite general in spring wheat throughout the southwest of Finland. In the extreme south-western part of the country the crop losses caused by drought and black stem rust were up to and over 50 per cent. In the eastern district of the area under review the damage by black stem rust was negligible in spite of heavy infection. 2. The coefficient of the correlation between the amount of black stem rust and 1,000 grain weight in the material collected from farms was —0.77 ± 0.04, and in a material obtained from the trial field —0.81 ± 0.05. 3. All the varieties grown in South-West Finland were susceptible to black stem rust. Kärn II, Diamant and Diamant II showed practically the same degree of infection. Thanks to its early ripening, the early Apu wheat in certain cases avoided heavy black stem rust infection. 4. On the trial field the north European varieties proved definitely more susceptible than many of the American varieties. Black stem rust was the most widespread of the wheat rusts in summer 1951 (cf. Table 3). 5. The younger breeding material revealed clearly the general susceptibility to black stem rust of the origins. It also showed the favourable effect on the descendants of the resistant parent strains employed in certain crosses. 6. A study of the origins of the Finnish varieties showed that hardly any varieties resistant to black stem rust have been employed as parents for our present commercial varieties.

Highlights

Puccinia graminis used previously to be very widespread and often destructive in the southern parts of Scandinavia, especially in Denmark
The purpose of the present study is to report, primarily from the plant breeder’s point of view, on the investigations and observations made by the Agricultural Research Centre, Department of Plant Breeding, in connection with the occurrence of black stem rust on the different spring wheat varieties in South-West Finland and especially on the spring wheat material grown in the experimental fields of the Department of Plant Breeding at Jokioinen
The paper reports on the black stem rust epidemic in South-West Finland in summer 1951, primarily from a plant breeder’s point of view

Summary

Introduction

Puccinia graminis used previously to be very widespread and often destructive in the southern parts of Scandinavia, especially in Denmark. It is considered a plant disease of no economic significance in Northern Europe, since the intermediate host of this rust species, Berberis vulgaris L., was destroyed by law in the most important catastrophe areas [9]. In Denmark, severe epidemics have been reported from before 1903 when the law ordering the destruction of the barberry bush was passed. In the summers of 1936 and 1937, so much black stem rust was observed in different parts of Denmark that those years are considered there as epidemic years [5]

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