There are five principles to growing a great fodder beet crop.
Sowing date
High yields depend on maximising sunshine hours. Aim to reach canopy closure by the longest day of the year—21 December.
Tech Tips:
- Aim to sow your beet crop when the soil temperatures reach eight degrees consistently. For most, this falls in October.
- Drill seed at a depth of 15 to 20 mm at a speed of around eight kph into a firm seed bed.
- Drilling must be consistent whether it is strip tilled or conventional cultivation. The choice of cultivation depends on the paddock and soil conditions at sowing.
- A cover crop, like oats or barley, sown just before the beet provides some wind protection to emerging plants; and may reduce impacts from early migrating aphids and virus yellow infections.
Plant population
The recommended sowing rate is 90,000 to 100,000 seeds/ha which allows for some natural field loses to occur.
Canopy expansion
There are two parts to leaf growth: leaf appearance and leaf expansion.
Leaf appearance is dictated by thermal time. It takes around 30°C for each leaf to appear in sequence and this is consistent for the first 20 leaves. Leaf appearance then slows as more shading between the plants occurs, and the plant directs resources to root development.
Leaf expansion and final leaf size is determined by how quickly the leaves expand and how long this expansion lasts. Warm temperatures and Nitrogen (N) determine expansion speed. While we cannot control temperature, we can ensure adequate N is available in the early part of the crop’s life. Quick establishment gets the crop to the 12th leaf stage which offers better resistance to virus yellow infections.
Tech Tip:
- Apply 50 percent of N at drilling and the remainder at two to four true leaves. There is no scientific evidence to suggest late N applications, post-Christmas, increases the final DM yield.
Weed control
Weeds compete for light, water, nutrients, harbour virus carrying aphids, and affect crop yields. Targeting weeds at the cotyledon stage, immediately after germination, eliminates the need for products or mixes causing crop injury.
Tech Tip:
- Treat leaf diseases, such as Cercospora, Beet Rust, Powdery Mildew and Ramularia, at the first signs of disease with a registered fungicide.
Canopy duration
Post canopy closure is all about maintaining green leaf area through late summer and autumn. When plant leaves die from foliar diseases, the plant diverts resources to produce new leaves, which means less green leaf is available to intercept sunlight; and impacts final yield.
Tech Tip:
- Mix your contact and residual chemistry as the crop develops to kill existing weeds and prevent others from germination.
