FACTORS AFFECTING THE GERMINATION AND ESTABLISHMENT OF MONOGERM SUGAR BEET
2.4.2 Plant population
Hull and Jaggard (1971) reviewed attempts to determine the population for maximum yield of sugar and found many factors, viz. soil type, irrigation, sowing technique and fertilizers, affected this optimum population. They generally concluded that this was 65,000 plants/ha on a fertile soil rising to 85,000 on poorer soils, but a few thousand above or below did not seriously depress yield. Goodman (1966) recommended 74,100/ha with a leaf area index (L.A.I.) of 2.8 (which does not intercept all available radiation but ensures there are no non-productive leaves). The above recommendations were based on hand-hoed situations only where a dense crop was sown and subsequently thinned. Draycott & Durrant (1974) looked at populations in relation to other cultural practices, and showed 50,000 or above was adequate without hand-hoeing. It was also shown that between a rectangularity of 1:2 and 1:1 yield was not affected at higher populations (86,000/ha) but Hull & Jaggard (1971) showed that 45 cm rows were more suitable for high populations and 60 cm for lower populations to reduce interplant competition in both cases. Interplant competition was shown to reduce individual plant yields considerably by Draycott & Durrant (1974) who compared sugar yields from plants grown in a competition free plot (22,000/ha with minimal nutrient and light competition and adequate soil water) with denser stands. At 22,000/ha individual plants yielded 315 g of sugar/plant but at 81,000/ha individuals yielded only 113 g, but a much higher total yield/ha.
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]
