Correct variety choice key to successful AD crop

Posted on

Hungry for knowledge on how to increase the output and efficiency of their AD operations growers from across the country gathered at the recent Hutchinsons Energy Crop Technology Open Day at Great Livermere, by invitation of Strutt and Parker Farms.
Assessing the performance of a range of new varieties with a particular focus on maturity and harvest date, Colin Button, Hutchinsons seed manager, pointed out that this year maturity has been difficult to predict with the effects of planting date and variable seeding rates, which were highlighted in the plots.  

“The range of development between the 15 varieties in the trial is really quite large. The earliest varieties showed good grain fill in the cobs with golden and firm grains, such as Pioneer’s P7892 and P7905.
The trial clearly demonstrated the importance of selecting varieties best suited to not only the site, soil type, aspect and fertility but also the harvest date ideally required.”

Harvest timing is critically important in order to prepare and leave soils in good condition for following crops noted Duncan Connabeer, Hutchinsons technical support manager.
“Increasingly, AD operators are looking for quality from a variety in the shape of dry matter and starch. These factors effect gas yield and should be central to variety choice. “

Guests from Agravis, a German company where the AD market is well established with over 8,000 AD plants, echoed this sentiment as German growers are increasingly looking at quality features of their maize varieties and earlier maturity in their variety choices.

“Later maturing varieties will be good for sites and management systems that can cope with October or even November harvest dates and can be complimented with earlier varieties where the site and system require a different approach,” said Mr Joslowski, seed sales manager.

Getting the crop off to a good start is crucial, emphasised Hutchinsons agronomist, Ed Stevens. “When faced with high numbers of weeds at cotyledon stage, early post emergence or pre-crop emergence bromoxynil and terbuthylazine have worked well.  Where following crops are not a concern terbuthylazine and mesotrione continue to be popular active ingredients.”  

assessing the performance of a range of new varieties with a particular foc
“A lesson from this season has been how reliant we are on crop competition for season-long weed control.  Most crops needed a follow up spray this year as further flushes of weeds germinated on moist sunlit soil between the rows. Due to a cold spring, crops did not grow away quickly allowing weeds a longer window to develop.”

A combination of active ingredients foramsulfuron, iodosulfuron-methylsodium and isoxadifen-ethyl as a post-emergence herbicide have given high levels of control of blackgrass but care must be taken to limit the exposure of populations to this active to minimise the chances of resistance developing. Continuing to rotate maize around the farm as part of an integrated cultural control programme is vital for all herbicides Mr Stevens stressed.

“Maize is often referred to as ’the hungry crop’ pointed out Rob Jewers, fertiliser specialist at Hutchinsons, reminding growers nutrition that correct nutrition is key to the production of maximum yield and quality.  

“Our nutrition demonstration plots at Gt Livermere have given us an excellent opportunity to evaluate a wide range of nutritional inputs tailored specifically to maize. Maize nutrition begins in the seedbed and traditionally a starter fertiliser is incorporated at planting to encourage strong rooting and vigorous early growth. “

narrow rows produced larger cobs
“Phosphorous is particularly important at this stage and many of the seedbed products demonstrated in our plots contained Phosphate, and zinc, which is essential for early growth and photosynthesis,” he added.

Also new for this year was a trial area to look at growing Maize under plastic, using different films with different varieties. With the cold spring early this year it was a good season to investigate this approach in the south, most commonly a tactic reserved for the colder north of the country.

The results showed that a range of varieties grown under plastic in conjunction with Samco at the site developed two weeks ahead of the varieties in the open. Although they were drilled at the same time, the crop under plastic could have gone in two weeks earlier which would have moved harvest dates forward considerably.

Technical manager at Hutchinsons, Dick Neale, demonstrated an investigation into row spacing questioning the conventional 750mm row spacings. 750mm rows were compared with 500mm rows and two plant populations 100,000 and 85,000 seeds/ha.
Water with blue dye was infiltrated and holes dug to reveal that when planted at 500mm rows, the roots meet between the rows, fully utilising the soil moisture reserve and available nutrients while the 750mm rows left around 15% of the cropped area under-utilised by the roots.

“One can see that the narrower rows are producing a larger cob yield,” said Mr Neale.
Plants sampled from plots where seedbed fertiliser had been applied had visibly larger roots that held on to far more soil than the control plots suggesting better water and nutrition retention properties.

All plots from the site have now been harvested and will undergo laboratory analysis which will be shared with clients in the following season.

Anyone growing crops for AD will be interested to know of Hutchinsons Dry Matter Challenge which encourages growers to raise biogas yields and which will share best practice amongst the entrants.