Sunboost for Potatoes and Sugar Beet
Optimum temperatures for potato growth are 15-20°c (1) and similar for sugar beet. Below these temperatures potatoes develop much shorter roots and lateral root formation is suppressed (2) thus exploring less of the soil available. This reduces the plants ability to absorb nutrients and also renders it more susceptible to drought should soils dry out more rapidly than new roots can be grown.
Increasing nitrogen supply enhances both shoot and root growth, but usually the shoot growth more than the root growth, leading to a fall in root/shoot dry weight. However roots do become more branched and the surface area increases so the capacity for water and nutrient uptake is less affected. The effect of increasing root surface area is more distinct if the source of N is ammonium rather than as nitrate (3) However broadcast application of N also encourages development of roots in the topsoil at the expense of subsoil penetration
Tuberization in potatoes can be delayed by the presence of large amounts of nitrogen, and after tubers have formed their growth rate will be reduced by high levels of N although top growth will be increased. Interruption and resupply of nitrogen can result in secondary growth of tubers and mis-shapen tubers.
In sugar beet a sudden increase in nitrogen will lead to excess top growth at the expense of the root.
In order to maximise yields without these detrimental effects spraying the crop with foliar SunBoost will supply readily available nitrogen and calcium. The urea form of nitrogen encourages good root growth without the excess top growth and the calcium will strengthen cell structure helping the plant to withstand stress and disease and produce good quality roots and tubers.
Applying granular nitrogen depends upon moisture to allow uptake, and on potatoes much of the nitrogen is likely to end up in the bottom of the ridges where it has little value to the crop. Most of this nitrogen is taken up in the nitrate form, even if applied as urea, and this will be transported to the leaves where it is converted to proteins. This process encourages greater top growth. SunBoost enables the plant to absorb N as NH2 either through the leaves or roots and encourages better root growth.
Since proposed new NVZ recommendations would cover over 70% of England it is essential that we find ways to utilize nitrogen as efficiently as possible to maintain crop yields and quality.
SunBoost is 3-4 times more effective than standard urea
Apply 20-25l/ha to sugar beet and potatoes
(1) Sattelmacher et al 1990
(2) Gregory 1983