scholarly journals DEPRESSION OF GROWTH AND YIELD IN WINTER BARLEY EXPOSED TO SULPHUR DIOXIDE IN THE FIELD

1986 ◽  
Vol 104 (2) ◽  
pp. 233-241 ◽  
Author(s):  
C. K. BAKER ◽  
J. J. COLLS ◽  
A. E. FULLWOOD ◽  
G. G. R. SEATON
1988 ◽  
Vol 109 (1) ◽  
pp. 67-78 ◽  
Author(s):  
A. R. McLEOD ◽  
T. M. ROBERTS ◽  
K. ALEXANDER ◽  
D. M. CRIBB

1991 ◽  
Vol 117 (3) ◽  
pp. 287-297 ◽  
Author(s):  
J. F. Jenkyn ◽  
R. J. Gutteridge ◽  
A. D. Todd

SUMMARYExperiments in 1985 and 1986, at Woburn Experimental Farm in Bedfordshire, tested the effects of fungicides, applied in autumn, and a growth regulator, applied at GS3O–31 or GS32–33 in spring, on winter barley grown on two contrasting soil types in each year. Leaf diseases did not become severe in any of the experiments but take-all (Gaeumannomyces graminis var. tritici) was prevalent in 1985. Triadimenol (‘Baytan’) was more effective than flutriafol (‘Ferrax’) in decreasing the severity of takeall and its activity against the disease was related to earliness of sowing.Mean responses in grain yield to the fungicide treatments were mostly small and not significant but did not conflict with the hypothesis that crops on lighter soils benefit more from autumn fungicides than those on heavier soils. Mean effects of the growth regulator sprays were also small but they interacted with both soil type and season. Over the 2 years the later spray applied to crops on the heavier soil gave the largest mean response. Sprays applied to crops on lighter soils were often detrimental to yield, especially in 1985.


1991 ◽  
Vol 117 (3) ◽  
pp. 279-285 ◽  
Author(s):  
K. C. Walker ◽  
S. Matthews

SUMMARYIn experiments conducted between 1982/83 and 1984/85 on the winter barley cv. Igri, nitrogen, including slow release forms, applied at several growth stages in the autumn, increased vegetative growth, including vegetative tiller numbers, nitrogen content and greening, particularly in the early sown crops. By spring, these effects were less apparent and only very infrequently did autumn nitrogen applications result in an increase in fertile tiller number and yield, although the autumn nitrogen treatments had been tested in combination with several different sowing dates and spring nitrogen levels. Studies on leaf production over the winter showed that the additional leaf produced after nitrogen application was subsequently lost through leaf senescence (especially in the severe winter of 1984/85) and therefore the treated and untreated plots often recommenced growth in the spring with similar amounts of live leaf tissue. It is argued that the use of autumn nitrogen on winter cereals in the north of Scotland cannot be supported agronomically and may also be undesirable for environmental reasons.


1992 ◽  
Vol 119 (3) ◽  
pp. 303-333 ◽  
Author(s):  
J. F. Jenkyn ◽  
N. Carter ◽  
R. J. Darby ◽  
R. J. Gutteridge ◽  
L. A. Mullen ◽  
...  

SUMMARYIn experiments at Rothamsted in 1984–86, seven factors, each at two levels, were tested in factorial combination on winter barley (cv. Panda) grown as a third take-all susceptible crop. The factors were seed rate, a growth regulator prior to stem extension, amounts of N in spring, ‘winter’ nitrogen, an autumn insecticide, a fungicide applied to the seed (‘Baytan’) and a programme of fungicide sprays in spring and summer. Sowing 50% more seeds than normal increased the number of ears/unit area but had no effect on mean grain yield because grains were smaller. There were, however, significant, but unexplained, interactions between seed rate and the fungicide ‘Baytan’ applied to the seed. A growth regulator applied prior to stem extension had little effect on crop growth and no significant effect on grain yield. If sufficient N was applied in April there was little benefit from applying ‘winter’ N (30 kg/ha in November and again in February/March) except in 1985 when the amount of NO3-N in the soil, measured in the previous October, was lowest. Insecticide sprays applied in autumn to control the aphid vectors of barley yellow dwarf virus (BYDV) had no significant effect on grain yield but infectivity indices were below the threshold needed for treatment in each year. On average, ‘Baytan’ applied to the seed increased grain yield by 0·28 t/ha and this was associated with decreases in the severity of take-all. Over the three years, programmes of fungicide sprays, applied during spring and summer, increased grain yield by 0·92 t/ha but the mean response was largest where most N was applied.The experiments also allowed the importance of interactions between different agronomic factors to be examined. A combined analysis of grain yields for all three years (based on 192 plot values) showed that only six 2- or 3-factor interactions, out of the 73 estimated, were significant (P < 0·05). Two of these interactions reflected variable responses to ‘winter’ N and fungicide sprays in the three years and three of the remaining four involved ‘Baytan’.Additional plots of barley grown after oats had little take-all and yielded 1·14 t/ha more grain than similarly treated plots grown after barley. These responses were obtained despite evidence that oat residues had adverse effects on the growth of barley seedlings. Additional plots of barley grown after a bare fallow also had little take-all and gave even larger total yields (grain plus straw) than did barley after oats but the mean yield of grain was less than after oats because more of the dry matter after a fallow was straw. In 1984, when take-all was relatively slight, plots after a fallow gave even less grain than plots after barley (−0·77 t/ha) despite producing 2·12 t/ha more dry matter in grain plus straw.


1987 ◽  
Vol 107 (2) ◽  
pp. 373-385 ◽  
Author(s):  
C. K. BAKER ◽  
A. E. FULLWOOD ◽  
J. J. COLLS

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