Aphid Alert

Wheat Drilled into Oat Stubbles

I think this could have possibly been one of the best autumns for establishing winter crops I can remember for quite some time. After the very dry summer months we started to get rain at just about the right time. This rain enabled weeds to germinate in the stubble's and cover crops before the main crops were planted. We had enough rain over the planting period to make sure that the seeds we planted germinated rapidly and emerged very quickly.

This year we have only used seed dressings with Zinc and Manganese on them to kick start the growth of the young plants, except on 1 block of barley we are growing for seed. Every year we have tested leaves for deficiency and these trace elements have always come up short.

One dilemma I have had is whether or not we should be spraying an autumn insecticide to control aphids. The aphids (Bird Cherry-Oat and Grain Aphids) could be carrying a virus called Barley Yellow Dwarf Virus which stunts the growth of plants and reduces yield. The only problem is you don't know if the aphids in our crops are carrying the virus and if the plants have been infected until the spring, when its too late to treat. The AHDB has developed a tool to assess when you should spray for aphids. This can play a crucial role when we are using Integrated Pest Management to responsibly use pesticides. This means that when we see a pest, we monitor its development and then spray with the correct product, with the correct amount of water and the correct dose rate to take the pest out. The tool can be found HERE 

As we are trying to reduce the levels of insecticide we apply on our fields I have decided not to spray half of the wheat area that was later planted but rely on our beneficial predators to help reduce the numbers of aphids. There are always lots of spiders webs across the fields and the aphids should provide a tasty snack! The Game and Wildlife Conservation Trust did some research which indicated that the effect on beneficial insects of that autumn spray was still apparent the following June.

Providing grassy margins around our field boundaries and beetle banks within larger fields also help create habitat for beneficial insects to live ready to strike at invading aphids. We will see in the spring whether or not this was a good decision! We need a good hard winter to help kill off as many aphids as possible.

Nuffield and the James Hutton Institute

Well where do I start?  I have had a very busy 10 days or so continuing my Nuffield research into the 20t/ha wheat project and it has literally taken me all over the country.  On Sunday the 10th February I had a lovely 8 hour drive from Overbury to Dundee, Invergowrie actually, home of the James Hutton Institute  I was there to meet Professor Geoff Squire the following morning to have a look around the research facility and see what is going on.  I was very interested in this area, firstly as I hadn't been this far North in a very long time and secondly, the JHI experimental farm is a LEAF Innovation Centre.  Monday morning soon arrived and after meeting Geoff I headed out with Euan Caldwell, the Farm Manager to tour farm.  The range of crops and experiments fitting into the fields was incredible and the 'commercial' aspect of the farm had to fit around the experiments.  There were blueberries, raspberries, kale, swede, onions, cabbage, radish, broccoli as well as potatoes and cereals.  The JHI hosts the annual 'Potatoes in Practice' event; hats off to Euan, there is a lot going on.  I was really interested in two main aspects of the farm, firstly the Centre for Sustainable Cropping system and also the genetic work on nitrogen uptake and efficiency, as well as some interesting faba bean nodule banter with Euan and Pete!

Whilst touring the farm Euan showed me another experiment going on capturing the water run-off along tramlines.  All the water is collected (in the mini culvert above) and analysed to measure nutrient and soil sediment loss.  Different tramlines have had different treatments to try and reduce erosion.  Some cultivated, some with different tyre patterns.  All very interesting and practical experiments, aimed to really make a difference on farm.

The sustainability field trials were a really great study topic.  How can a 6 year rotation be evaluated for it's impact on the environment?  The JHI guys and gals, were trying to find out.  The project is being coordinated by Dr Cathy Hawes and involves 6 fields split down the middle with the two halves being managed in different ways.  The, shall we say conventional, half is managed with current best local practise and the sustainable half is managed in a way as to maintain crop output but with a reduction in crop inputs.  This reduction is in the way of artificial fertilisers, fuel and pesticides.  Everything imaginable is being monitored leaving the systems.  Soil movement in the different cultivation techniques, weed seed bank movement, nematode movement, water movement and even small mammal trapping to see if they prefer the sustainable farming method.  The project is in year 4 now, having had to years of straight maize (a C4 plant in a C3 rotation so the degradation rates can be monitored) and two years of the proper rotation.

Here's a view of one of the fields with a beetle bank through the centre.  It will be a fascinating research project and hopefully funding will continue to keep this going for more than a couple of rotations, i.e at least 15 years.  We need this research to measure longer term farming interactions with our environment.

The second area of interest was the work being undertaken by Dr Ali Karley she is looking into root traits for better or more efficient use of nitrogen.  In fact has the wheat breeding in the past been aimed at breeding wheat varieties that only perform well in high input, especially nitrogen, farming systems.  Ali's work is looking at finding traits that enable wheat plants to perform in lower input systems, or those traits that make the plants more tolerant of sub optimal fertility sites.  I learnt that there is about 3,000-4,000Kg of Nitrogen locked away in each hectare of soil (varies a little depending on soil types etc), mainly in organic matter and that plants are fairly efficient in the UK farming system at utilising the nitrogen we deliver through organic and inorganic systems.  I also heard about utilisation efficiency, how much of the nitrogen gets into the grain, (yield and quality implications).  I was also very interested in the work looking at root penetration of compacted soils.  Can we breed wheat plants with stronger more robust rooting systems to be more efficient in their nitrogen utilisation as well as bust through a compacted layer during difficult seasons when compaction could be a problem?

I would like to pass my thanks on to Geoff and his team for looking after me so well and sharing lots of very good information.  I fear that this may not be my last trip to Dundee!  After Dundee I headed back done the motorway to Rothamsted.......