Enhancing Crop Health

Since the late nineties, when strobilurin fungicides were introduced and then reinforced with the introduction of prothioconazole, modern fungicides have been known to have beneficial physiological effects. These effects include enhanced greening though increasing the level of respiration and enhancing chlorophyll production.

While prothioconazole, the active ingredient in Proline, and a component of Prosaro and Delaro, is impressive in this respect, enhanced crop health has now been taken to a new level with the introduction of Aviator Xpro.

Aviator Xpro combines the activity of prothioconazole with bixafen, a highly active SDHI fungicide which adds a new suite of crop health attributes.

Aviator Xpro delivers exceptional control of a very broad spectrum of diseases, and controlling disease naturally increases plant health but here we are describing non-fungicidal benefits. Aviator Xpro has been scientifically proven to reduce the impact of drought stress and to increase crop greening.

These improvements in plant health are having a practical impact for farmers with significant and profitable yield increases being measured, even when disease levels are low. So low that some may question the commercial sense in applying a fungicide programme.

While conducting a series of trials in Canterbury during spring 2015, Bayer was faced with crops carrying very low disease levels. While this wasn’t the plan, it did present an opportunity to quantify the effect of Aviator Xpro’s non-fungicidal activity!

The results were certainly impressive. In the Methven area the trial only carried 13% Septoria leaf blotch on leaf three and around 1% on the flag leaf. With these low levels of disease the expectation would be for no significance difference in yield. In fact a programme based on Aviator Xpro and Prosaro delivered a yield increase of 1.9 t/ha which resulted in a profit over fungicide cost of $215/ha.

Prothioconazole and bixafen trial Arable Fungicides Bayer

Similarly at Barhill low disease levels were recorded but the return was $140/ha and in a trial near to Timaru, where even lower disease levels were recorded, applying the fungicide programme delivered a yield increase of 1.2 t/ha which resulted a profit over fungicide cost of $40/ha.

So where is this disease increase coming from?

Since 2010 Bayer has been measuring the NVD Index of trials using a Greenseeker machine. NVD stands for Normalized Difference Vegetation and is essentially a measure of the greenness of the crop (the score is measured from 0 to 1.0 with 1.0 being the highest).

In the trials referred to above, it was found that in the Methven trial, 5 weeks after the last treatment the NVD index of the Aviator / Prosaro, treatment was 33% higher than the untreated. Similarly in the Timaru trial, the Aviator / Prosaro treatment had a NVDI score 36% higher than the untreated.

This is strong evidence that Aviator Xpro is maintaining the green leaf area for a prolonged period of time and that this is having a strong impact of yield delivery when disease levels are low.

Is the same effect being found in barley?

Again in spring 2015, Bayer was fortunate to have a trial which was infected only with Ramularia leaf spot, and assessed disease levels were 10% in the untreated. This time a fungicide programme incorporating Delaro and Aviator Xpro resulted in a yield increase of 1.1 t/ha. This fungicide programme delivered a profitable return of $103/ha.

These trials demonstrate that applying a robust fungicide programme, utilising the powerful fungicide portfolio offered by Bayer Crop science, has a high probability of delivering a handsome profit whatever the disease level.