GIVEN the dry spring, some arable crops are coming under drought pressure, exacerbated by micro-nutrient deficiencies and it looks like a season for foliar treatments to come to the fore.

Many areas have received around 85% of the long-term average rainfall so far this year, despite March being wetter than normal, but the dry April means that some areas have significant moisture deficits.

“Most crops got off to an early start with the warm February, and a lot of farmers applied nitrogen early so the crops grew on ahead of normal,” pointed out Bryn Thomas, an agronomist at Spunhill, Shrewsbury. “But since then everything has slowed down, with lengthening days and warmer soils required for growth stage progression.”

Many crops have used up the early-applied nitrogen and the dry weather has also limited nutrient availability, stalling crop growth, he adds. To help alleviate drought stress, farmers should consider adding a proven biostimulant to their T1 fungicide application, he argued.

“We’ve been doing split field trials looking at yield and crop health with bio-stimulants and the science backs them up. As we lose more pesticide active ingredients, we’re going to have to do more to look after plant health and last year we found biostimulants like Proplex helped alleviate drought stress.”

Doug Chaplin, operations manager at Olmix-Micromix, said he recommended using either C-Weed AAA or Proplex to stimulate root and plant development. “C-Weed AAA contains a highly concentrated extract of ascophyllum nodosum, which has unique marine-based compounds that alleviate stress and stimulate growth in land plants. It is also high in natural plant amino acids which are essential for cell growth.”

Proplex, though, is a more complex formulation he pointed out. “It’s shown to promote root hairs, not just root length – and that is the active part of the root that takes up water and nutrients. Under stress, plants tend to start shutting down, but these biostimulants keep them growing for longer, ultimately boosting yield and quality.”

Mr Thomas has been carrying out a lot of tissue analysis on farms, which has thrown up nutrient deficiencies this spring, particularly in magnesium, zinc and boron, which are essential for growth and fertility. “We’re looking at using foliar nutrients including manganese, magnesium, zinc and copper alongside the biostimulants. The advantage of foliar application is that you get rapid uptake and target nutrients straight into the leaf in a bio-available formulation.”

Magnesium deficiency is showing up in a lot of recent analysis, and it will be important to address this at T1 in wheat, as it is key for chlorophyll production and photosynthesis, warned Mr Thomas.

“Boron – often considered important for oilseed rape and sugar beet – I think is a hidden hunger and in cereals is vital for fertility and ear formation. It’s important to get the balance right as in high levels it is phyto-toxic. That’s where tissue testing proves its worth – rather than blanket application you know that you’re doing the right thing,” he said.