BASF Intrinsic® brand fungicides – including Pageant® Intrinsic®, Empress® Intrinsic® and Orkestra® Intrinsic® products - are based on the active ingredient pyraclostrobin, proven to deliver both disease control of major foliar and root diseases as well as plant health benefits. Intrinsic-based fungicides stop fungal infection through inhibition of mitochondrial respiration, preventing the production of energy that fuels the growth of the fungi resulting in death. In plants, the active ingredient pyraclostrobin interacts in plant mitochondrial respiration resulting in greater carbon and nitrogen utilized for plant growth. By using BASF Intrinsic® brand fungicides, growers can see greater rooting, branching and bud development Overall improved tolerance to environmental stresses during plant growth have resulted in increased efficiency in plant growth.
Figure 1. Source: Schematic proposed by BASF Global AG Research, Germany, 2001-2009
Pretreatment activates plant defenses
Faster and/or improved defense responses by plants to pathogen attack reduce the impact of disease. Faster response helps reduce plant losses even when plants can fight off the disease. Pageant Intrinsic, Empress Intrinsic and Orkestra Intrinsic are used for preventative broad-spectrum disease control. As shown in the diagram below, Intrinsic-based fungicide applications increase nitric oxide, which in turn blocks ethylene, an infected plant response. Growers build their disease control program around maintaining a healthier plant. Intrinsic-based fungicides have been shown to activate plant defenses so that plants are better prepared to defend themselves when pathogen attack occurs.
Improved photosynthesis for increased growth
Today’s growers seek to maximize plant quality as maintenance costs continue to rise. Growers want to know that when they invest money into inputs like fungicides, those inputs will achieve the highest potential. Plants treated with Intrinsic-based fungicides are healthier and stronger.
Increasing the efficiency of photosynthesis allows a plant to make the best use of available inputs. The activity of pyraclostrobin based fungicides on plant mitochondria reduces respiration in plants. This reduction in respiration reduces the amount of CO2 given off when stored carbon compounds are broken down in the night respiration cycle (Figure 2). These stored carbons are made available for growth and development and are what we call Increased Net Photosynthesis.
Figure 2. Source: Köhle et al 2002 in Modern Fungicides and Antifungal Compounds III, Eds. Dehne, Gisi, Kuck, Russel and Lyr.
A research study was conducted to determine the effect of pyraclostrobin on the enzyme nitrate reductase. Within a few hours after a pyraclostrobin application to wheat leaves, the activity of nitrate reductase increased by more than 70%. The increased nitrate reductase activity was maintained for more than three nights after a single application of pyraclostrobin (Figure 3).
Figure 3. Source: Köhle et al 2002 in Modern Fungicides and Antifungal Compounds III, Eds. Dehne, Gisi, Kuck, Russel and Lyr.
Improved tolerance to drought
Ethylene is a hormone which plants produce in response to many stresses, including drought stress. Plants also produce ethylene in response to injury, when they mature, prior to leaf loss, and before pathogen-triggered cell death. Nitric oxide inhibits the enzymes involved in the production of ethylene. The more nitric oxide, the less ethylene produced. Since nitric oxide levels in a plant are often increased after a pyraclostrobin-based fungicide application, the amount of ethylene in treated plants is also reduced (Figure 4). The inhibition of ethylene production by pyraclostrobin was compared to other strobilurins. Forty-five hours after the stress started, pyraclostrobin reduced ethylene production by 33% more than strobilurin 2 and by 67% more than strobilurin 1.
Figure 4. Source: H. Schiffer, BASF Global AG Research, 2001-2002
Figure 5. Pageant Intrinsic treated plants on left; competitor in center and untreated on right, following power outage. Trials 2009-2010, BASF, Research Triangle Park
Intrinsic brand fungicides improve tolerance to environmental stresses
Heat stress is linked to increased superoxide dismutase (SOD) activity. Nitric oxide is also linked to increased heat tolerance. Pyraclostrobin applications increase both SOD activity and the production of nitric oxide by increasing the activity of nitrate reductase. Thus, pyraclostrobin applications can improve plant tolerance to heat.
Figure 6. Untreated plants on left, Pageant Intrinsic plants on right following drought event and rehydration. Trials 2009-2010, BASF, Research Triangle Park
BASF Intrinsic brand fungicides, based on pyraclostrobin, are helping growers not only control diseases, but also reduce the effects of stresses on their plants. This allows these professionals to meet their customers’ expectations by providing ideal plants