Thursday, 25 January 2018
Key steps for a successful fodder beet crop
Fodder beet can form an important part of your herd’s winter diet, but it's susceptible to several foliar diseases at this time of year. Early prevention ensures you get the most out of your crop come winter.
Diseases to monitor
We are already seeing Beet Rust and Cercospora disease appearing so it is important that you monitor your crops regularly at this time of year. The fodder beet growth phase during late summer and early autumn needs to focus on green leaf retention for as long as possible for good bulb development come winter.
The main foliar diseases we are concerned with are Beet Rust, Cercospora, Powdery Mildew and Ramularia. These diseases can reduce yield to varying degrees but, in the case of Cercospora overseas, data suggests anything from forty to fifty percent. In addition, maintaining green leaf area can protect the bulb against early frosts prior to grazing or harvesting.
Identifying fungal pathogens now is important, as these diseases will start during late January and early February. It is imperative that growers do not wait until disease is present because the two fungicides available are more preventative than curative. Once disease is showing, the fungus would have been present in the plant for some time due to the latent periods of the pathogens.
An appropriate management plan for a crop at this time of the year is a two spray programme four weeks apart, beginning when the first signs of disease show.
An irrigated crop that has good potential should definitely get two spray applications, but in a dryland situation, one spray application might suffice. I’d rather see the grower invest in disease control. Once the crop canopy closure has been reached, then applying late nitrogen.
Late nitrogen applications will only increase top growth and not necessarily root growth. The function of nitrogen in beet is to drive canopy growth so application is better earlier than later. Leaf tissue tests should be taken prior to the fungicide application so that any nutrient deficiencies can be rectified with a foliar spray in conjunction with the disease control if necessary. If an appropriate base fertiliser was applied at sowing, it is highly unlikely that more nutrients will be required at this time of year. Occasionally we pick up a Boron, Magnesium or Manganese deficiency, but it is more cost effective to apply as a liquid than a solid, especially as most of the nitrogen should have been applied early.
The success of your fodder beet crop comes down to regular monitoring. If you have questions or concerns contact your Agri Manager or Agronomist.