Nov 2020

6 Critical Steps to Grow a 15t Turnip Crop

We sometimes hear that Turnips always grow great when they aren’t needed, and poorly when they are most needed. Other than in cases of severe and early drought, research and experience shows otherwise. Most poor crops come from poor agronomy. No, turnips won’t grow themselves!

Did you know?

With everything done right, a good turnip crop can yield over 15tDM/ha at 12.5 MJME when pastures are struggling to grow and at only 10.5 MJME.

This raises the question… COST vs YEILD – Where does the balance sit?

A low yielding turnip crop is a costly mistake. If you continued to grow grass instead of planting turnips, you could safely budget on growing 4tDM/ha from October 1st to March 30th – and this is at no extra cost.

In autumn, pastures have lower ME and no F.E protection. You either offer supplement to cover your feed deficit (at higher cost) or just take the drop in production on the chin (less profit) and the consequential overgrazing of your pastures should the season go dry. This same effect occurs when you grow a low yielding turnip crop.

Low Yield = More Cost/kgDM + Less Profit + Less kg/MS + more perennial pasture overgrazing damage

This will sound familiar to farmers who have grown turnips. The frustration is difficult to deal with… What did I do wrong? Why have others grown better crops? Should I be using something else?… the list goes on.

The Trial proves it…

In a series of farmers 35 observations in 2002 / 2003, many Waikato and King Country farmers were given a turnip growing program to work from and their yields measured. Some kept to the program, and others didn’t. You can see from the following results the effect of following an effective program.

“When the protocol was followed there was only one instance when the yield was less than 10 t DM/ha and in more than 60% of the cases yields were in excess of 12 t DM/ha.

In 33% of the cases where the protocol was not followed, yields were under 10 t DM/ha and in only 22% of the cases was the yield in excess of 12 t DM/ha.” (Eerens and Lane 2004)

It doesn’t pay to cut corners – proven!

So how can I ensure maximum yield?

Here are six tips we can provide that have been tried and proven by many Smart Farmers, read carefully:

  1. Plant at the right time. Later planted crops often miss early moisture. Optimum planting date is Labour weekend. Too early, the soils are too cold, germination too slow and struggling plants are easily picked off by insects or disease. Too late, you don’t get moisture at the critical time for growth and ground cover.
  1. Sow at 3 kg / Ha. The quicker to canopy cover, the less weeds and greater moisture retention. High sowing rates grow more leaf, but in our experience, no less yield. Conversely, a low sowing rate has too much potential for risk. You need a lot of stars lined up in your favour i.e. weed control, insect control, excellent weather conditions – to get away with a low sowing rate. Of course, if you are precision planting with palletised seed, the whole program changes dramatically. Jung and Shaffer (1993) showed that there was no difference in yield from sowing between a range of 1.7 – 5 kg / Ha of Turnip seed. The only difference was ratio of leaf to bulb.
  1. Control insects proactively. Use insecticide at spray out, Insecticide coated seed and monitor for pest invasion during the course of the crop. Leaf Miner left unchecked can have the same effect as putting paint on a solar panel – reducing crop yield. Often confused for Leaf disease, and one of the main culprits for causing poor yields.
  1. Control weeds proactively. Best practise uses a pre emergence herbicide. If not possible, post emergent herbicide is the next best option. However, watch for the clover plant back timing. If you don’t spray until weeds become an obvious problem, you’ve missed the boat.
  1. Sort your fertiliser requirements early, and don’t ignore your N applications. 100 kg N pre plant and 100 kg N 3 – 4 weeks post planting.
  1. Monitor, monitor, monitor – especially at the early stages of the crop. Use the services of Smart Qualified Agronomists to monitor your crop. “Left to chance” is not an option.

Picture yourself at the other end of the season,

  • Lower cost per unit of ME
  • Slower decline in MS production during autumn
  • Better pasture persistence from reduced pressure of overgrazing
  • New pastures planted behind the turnip crop to increase future production
  • Increased Profit
  • Happy Farmer

Smart, making your life easier and more profitable

Know others growing turnips?
Please feel free to share this with them.

Until next time, all the best and keep smiling!

The Smart Team

Eerens J.P.J. and Lane P.M.S. Best management practice turnip production: how to target a 14 tonne/ha crop on a central North Island dairy farm
Jung, G.A.; Shaffer, J.A. 1993. Planting date and seeding rate effects on morphological development and yield of turnip. Crop Science 33: 1329-1334