Yield Trends during Take‐all Decline in Spring Barley and Wheat Grown Continuously¹

Abstract

The effects of take-all, nitrogen and cropping sequence on grain yield were compared for spring barley and spring wheat grown in extended monoculture. Initial crops showed least take-all and maximum yields. Yields fell to a minimum more rapidly in wheat than in barley while the take-all intensity increased to a maximum ; take-all decline occurred and yields improved from the 4th and 5th years respectively. Without nitrogen, yields were at their lowest level ; application of nitrogen increased yields considerably with responses in proportion to the rate applied. At optimum rates, yield losses were 33 96 for wheat and 11 96 for barley with maximum disease intensity but only 9 % and 3 k respectively with take-all decline. Potential maximum yields in the absence of take-all were calculated to be greater with barley than with wheat. introduction A detailed description has been published (SHIPTON, 1972) of the development of the take-all disease of cereals (caused by Gaeumunnomyces graminis [Sacc.] Arx & (Xivier var. kitici J. Walker) and the onset of take-all decline (TAD) on spring-sown wheat grown in monoculture in trials in the south of England.In view of the considerable possibilities for the commercial exploitation of TAD there is need for information on factors influencing the yield of cereals grown continuously under a range of conditions. This paper describes further the relationship of the yields of grain harvested over a 7 year period (1963)(1964)(1965)(1966)(1967)(1968)(1969) with take-all and applied nitrogen (N). Materlals and MethodsFull experimental details of the phased introduction of 6 cropping sequences (A-F) in the spring barley and spring wheat trials (site A) and of the continuous spring barley trial (site B) at Winchester, Hampshire, have been given in an earlier paper (SHIPTON, 1972) which describes the assessment of take-all and presents data on the incidence and severity of take-all, with particular reference to the development of TAD. These results are summarized in tables 1-3.Yields of grain at maturity were calculated from the amount of grain obtained by combine-harvester from an area 60 f t (18.3 m) x 8 f t 2 in. (2.5 m) equivalent to 0.011 acre (0.0044 ha), and corrected to 85 96 dry matter content.

Growth and yield of winter wheat in the first 3 years of a monoculture under varying N fertilization in NW Germany

“…The yield of the third wheat crop, following wheat-wheat, achieved the lowest yield, being 20% less than that of the first wheat crop. Other researchers also reported of dramatic yield decreases by 30-40% in the first 3-4 years of a wheat monoculture and an increase in the following years, known as 'decline-effect' in the larger sense (Gerlagh, 1968;Shipton, 1975;Sieling and Hanus, 1990).…”

Meeting the demand for crop production: the challenge of yield decline in crops grown in short rotations

“…Further evidence for yield decline occurring with more frequent cropping can be found in studies focussing on aspects such as soil microbiology or plant pathology of a particular crop, e.g. wheat or potato ( Solanum tuberosum ) (Larkin & Honeycutt, 2006; Shipton, 1975). Table 2 provides representative examples of yield decline reported for some major crops, and the hypothesised mechanism responsible for the yield decline, where investigated.…”

Crop rotation effects on yield of oilseed rape, wheat and barley and residual effects on the subsequent wheat

“…No significant differences in grain yield or during the growth period due to the preceding crop or the crop rotation occurred. Wheat grown on plots of the former OSR monoculture yielded only 458 g m −2 , whereas the yield of rotation 2 (wheat monoculture) was surprisingly high (882 g m −2 ), presumably due to the 'decline-effect' in the larger sense after 14 years of continuous wheat (Gerlagh 1968;Shipton 1975).…”