corn leaves

Pillars of plant health

May 11, 2023 7:30 a.m.


Every season has its challenges — periods of hot and dry, cool and wet, hail and wind — when plants need protection from more than disease alone.

Any fungicide that’s worth its weight will control disease. But what about helping combat environmental stressors like heat and drought? How do you know which products stand up to their claims and which products fail to yield results?

Growers should look to a fungicide that will support plant growth and yield optimization in three ways:

1) proven disease protection

2) increased environmental stress tolerance

3) improved growth efficiency

Disease Protection

When disease infects a crop, a lot can happen before you even see a lesion. The time between infection and reproduction is known as the latent period. During the latent period, diseases invade crop tissue, produce toxins, and reduce productivity. All corn and soybean diseases have a latent period which can result in widespread destruction before you are even aware there is a problem. Listed below are latent periods for several common corn and soybean diseases:

  • Frogeye Leaf Spot: 7-10 days1
  • Target Spot: 8 days2
  • Southern Rust: 7-10 days3
  • Tar Spot: 14-20 days4

Some diseases, like tar spot in corn, have long latent periods – 14-20 days in which a disease is wreaking havoc inside plants while remaining undetectable to the naked eye. Electron microscopy images like the ones shown below, provide the proof to be proactive instead of reactive. Just because you don’t see something doesn’t mean it isn’t there. Planned applications of fungicides ensure protection from diseases before it’s too late.

BASF Trial
Figure 1. Five days after disease inoculation of grey leaf spot, electron microscope images demonstrating fungal hyphae (orange) on a corn leaf surface (green). The image on the left shows the fungal hyphae entering the stomata. No visible fungal lesions are evident on the leaf surface.

BASF Trial 15 days
Figure 2. Fifteen days after disease inoculation, electron microscope images show an expansive hyphal network forming throughout the vascular bundle of the leaf tissue. For the first time, small lesions are starting to become evident to the naked eye.

BASF TrialFigure 3. Nineteen days after disease inoculation, lesions are easily visible (represented by brown leaf tissue on the left). The disease is preparing to enter reproductive mode and spores will form on those lesions.

Growth Efficiency

Growers can still improve yield potential even if disease doesn’t strike. Utilizing a BASF Plant Health product increases nitrogen assimilation in plants. Nitrogen is a key component of chlorophyll molecules, which in turn, are critical to photosynthesis. Increased nitrogen assimilation and chlorophyll production support plants’ overall health and ultimately, drive yield.

BASF graph

Figure 4. Application of BASF Plant Health product, Priaxor® fungicide, on soybeans. Application resulted in a 9% increase in photosynthetic rate and 5 bu/A yield advantage.

Environmental Stress Tolerance

Plants are subject to many stressors – not just disease. Heat, drought, hail, cold temperatures, etc. can result in yield loss during any given season. When plants undergo stress, they produce ethylene, a plant stress hormone. This hormone signals for the plant to close their stomata in an effort to conserve water. This results in increased internal plant temperatures.

BASF Plant Health products reduce the levels of ethylene produced when plants undergo stress. By reducing ethylene, stomata are able to remain open, allowing for normal gas exchange and facilitating cooler canopy temperatures (Figure 5). The plant also continues to photosynthesize and generate yield.

Third-party, small plot replicated trial, ND 2018. Veltyma fungicide 7 fl oz/A applies to VT corn

Third-party, small plot replicated trial, ND 2018. Veltyma fungicide 7 fl oz/A applies to VT corn

Figure 5. FLIR/thermal images depicting cooler temperatures (i.e. more blue and green colors) in the corn treated with BASF’s Plant Health product, Veltyma® fungicide.

In summary, the best way to protect your crop from multiple stressors is to implement a planned, preventative fungicide application. Utilizing a BASF Plant Health product like Veltyma® fungicide in corn or Revytek® fungicide in soybeans not only helps stops disease, but they also increase growth efficiency and environmental stress tolerance to protect your hard work and help maximize yields.




2: Molina, “Yield losses of soybean due to target spot (Corynespora cassiicola), its genetic and chemical management” 2018.