FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET
2.4.8 Other emergence factors
(i) Fertilizers
Providing the recommended rates are used (100 Kg/ha N, 100 Kg/ha P205 & 200 Kg/ha K20 MAFF 1979), fertilizers do not have a large effect on establishment except for nitrogen which can be used to encourage early leaf growth. Nitrogen should be applied in the Spring at least two weeks before sowing to allow high localised concentrations to be diluted by rainfall before scorch damage of seedlings occurs (Last & Draycott 1979). The other nutrients, and, if required, Na and Mg, can be applied in the Autumn (Draycott 1977).
(ii) Fungicides
Byford (1977) studied the effects of mercury fungicides on emergence. Maneb, Captafol and 2-(Thiocyanome-thylthio) benzothiazole (T.C.M.T.B.) seed treatments were compared with the standard E.M.P. treatment. No treatment was as good as E.M.P. and only maneb was similar. It has been estimated that national emergence would be 10% lower if E.M.P. was replaced by another fungicide. Other environmental factors had much larger effects on emergence overall, but E.M.P. treatment is definitely justified as the untreated control had a 20% lower emergence.
(iii) Pests
Pest control measures in addition to seed dressing are sometimes required for pests which effect establishment. Millipedes and beetles can be troublesome but Gamma HCH worked into the seed bed before sowing gives control. Wood mice which dig up seeds and seedlings can be controlled by traps or poisoned food if numbers are high after a mild winter (Farmers' Weekly 1979).
(iv) Weeds
Weeds are no longer a major problem to establishment as good herbicide control is now possible with soil acting herbicides such as chloridazon or ethofumesate (Bray 1980).
(v) Cold injury
Cary (1975) showed that seedlings on the point of emergence were more sensitive to frost damage than at any stage before or after, and that no chemical used to promote winter hardiness in other species affected sugar beet similarly. However, germination at low temperature and osmotic treatments did reduce sensitivity to frost damage.
(vi) Soil temperatures
The effects of soil temperature are more important than the actual sowing date as Scott et al (1973) have shown. The date that the amount of accumulated day degrees over 5°C begins to increase rapidly is a good indicator of the onset of growing weather. However, this can occur at any time between lst March and 20th May, but most commonly between the lst and 10th of April. It is usually best to sow just before the onset of growing weather.
FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET
[Introduction & Contents] [Chapter One] [Chapter Two] [Chapter Three] [Chapter Four] [Chapter Five] [Chapter Six] [Chapter Seven]
[2.4] [2.4.1] [2.4.2] [2.4.3] [2.4.4] [2.4.5] [2.4.6] [2.4.7] [2.4.8]
