Trials give fresh hope for sustainable wheat yields

Better wheat yields could achieved by using biostimulants to reduce reliance on fertiliser and agrochemicals, suggests a trial.

Carried out by plant breeder KWS and biostimulants specialist Orion Future Technologies, researchers who treated wheat with silicon found that the crop was better at taking up essential nutrients.

These included iron, manganese, copper and zinc as well as silicon, said Orion agronomist Mike Stoker. “This makes the plant stronger and better equipped to resist climatic and biotic stresses, which has resulted in higher yields.”

The trial set out to establish how KWS wheat varieties accumulated silicon when it was applied in the form of bioavailable liquid Sirius. The wheat varieties were KWS Dawsum, Extase, Palladium, Ultimatum and Zyatt.

In scavenging for the added available silicon, Mr Stoker said the wheat naturally encountered and took up increased levels of other beneficial nutrients – as well as downregulating the uptake of substances like aluminium and sodium.

The variety KWQS Ultimatum had the highest accumulation of iron and showed the highest yield increase – a boost of 16%. Sirius was applied at 0.25 litres/ha and at 0.5 litres/ha to see if a higher dose would provide better results.

Improvements

“Interestingly, most varieties responded similarly to both doses, showing that just a small increase in silicon uptake can provide considerable yield improvements,” said Mr Stoker, probably due to the way Sirius mixes in the tank.

“We often find lower doses remain efficacious because bioavailable silicon breaks apart in water, so using less provides the molecules more capacity to separate.

“It is also important to add that silicon does not have a detrimental effect on any other products being used, including fertilisers and plant protection products.

The most consistent improvements in the uptake of nutrients measured was found with the variety KWS Extase. Benefits to the plant brought a yield increase of 7%.

Uptake of boron, copper, manganese, zinc and iron all increased when Extase was treated with Sirius. Once absorbed, silicon was deposited within and between the cells of the plant which increased dry matter levels, and had a positive effect on yield.”

Iron deficiency is exacerbated by waterlogged soils like those seen in this growing season. Mr Stoker says that this can seriously diminish yield and the final nutritional quality of crops, particularly in alkaline soils.

He further suggests that manganese deficiency has been identified as the most widespread trace element problem in UK arable crops and is also commonly associated with persistently wet soils.

“As manganese is linked with both disease resistance pathways and winter hardiness, an autumn application of Sirius lends itself to stronger cereal crop performance the following spring.

“The trials have shown that applications at T2 will provide benefits such as reduced lodging, enhanced drought tolerance and better nutrient flow into the forming grains.”

Courgettes show benefits from silicon too

Applying silicon to courgettes almost doubled the weight of the fruit – and helped strengthen the plant against powdery mildew.

The link between plant health, fruit weight and silicon uptake was identified by a postgraduate student undertaking a glasshouse study at Hertfordshire University. The trial used 40ml of silicon biostimulant Sirius at a concentration of 0.2%.

Research supervisor Avice Hall said: “The findings are very encouraging for any grower looking to boost plant health and courgette weight while mitigating the effect of powdery mildew.”

Silicon was applied to the soil on a weekly basis for eight weeks. It was compared to a control sample given deionised water in the same volume as the treated plants received silicon to ensure both received the same amount of water.

“The average weight of courgettes treated with Sirius was 180g which, compared to the control at 95g, shows that the addition of silicon almost doubled the weight of the fruit,” says Dr Hall.

The study also charted the effect of powdery mildew on the plants. By leaf counting, the study identified that, in almost all of the eight weeks, the silicon enhanced plants had fewer infected leaves.

The addition of silicon also helped the treated plants produce more courgettes and, by week four, the average number of the fruits was almost six, compared with four fruits produced by the untreated plants in the same time.