Stem base rot (Phytophthora cactorum): the approach will change in the coming years

What is stem base rot (Phytophthora cactorum)
Infestation occurs through wounds in the rhizome. This mainly happens immediately after planting. In affected plants, a reddish-brown discoloration is found when cutting the rhizome lengthwise. Once most of the rhizome has been damaged, seen in the horizontal plane, the plant withers and dies. This disease progression can occur very quickly. This fungus should mainly be tackled preventively and entry ports must be taken into account with any crop damage.

Mode of action Aliette en Serenade

Aliette
Fosetyl aluminum (active substance of Aliette) is a systemic fungicide with protective action against a number of oomycete and ascomycete fungi. Aliette is rapidly taken up by both leaves and roots and exhibits both acropetal and basipetal movement in the plant (from root to above-ground growing points and from above-ground growing points to the root). The mechanism of action consists of inhibiting spore germination and blocking mycelium development. In addition, Aliette induces plant defense mechanisms against fungi.

Serenade (biological fungicide/bactericide, active ingredient Bacillus amiloliquefaciens QST 713)
Serenade is a contact fungicide produced through fermentation. During the manufacturing process, a series of secondary antifungal compounds known as lipopeptides are produced by the bacteria. These lipopeptides disrupt the pathogen's cell membrane, resulting in physical breakdown of the fungal cell upon contact. A unique mechanism of action. This mode of action is particularly important when Serenade is used in combination with other fungicides. Because Serenade causes membrane disruption, the fungicide it is combined with has better access to the pathogen.

Serenade has also been shown to activate the plant's defense mechanism. This means that Serenade encourages the plants to defend themselves against pathogens. If Serenade is applied through the roots, Serenade will colonize on the roots. During the growth of the bacteria on the roots, lipopeptides are formed again and again and the plant is activated to defend itself against attackers. In short, a long-lasting effect.

A golden duo for combating stem base rot
Aliette and Serenade are a golden duo for soil and root-related diseases. Looking at the mechanisms of action of the two fungicides, it is clear that they strongly reinforce each other. Serenade ensures that Aliette can do her work more effectively because Serenade punctures the cell membranes of the fungi, making the fungus more sensitive to Aliette. In addition, Aliette also has a direct effect against fungi. Finally, both products activate the plant to activate its self-defense mechanism, making the plant more resilient.

Trial results with the combination
With a number of years of basic research, we can conclude that the combination of Aliette with Serenade is a strong strategy compared to Paraat, which is currently often used.

The graph below shows the effect that we have seen repeatedly in our tests: starting with a watering treatment just after cuttings (moment A), followed by crop treatments afterwards, with an interval of 7 days each (moments B, C, D). Our system with Aliette and Serenade produces a healthier crop than treated with dimethomorph at the same times.

Advice
With the disappearance of active substances, alternatives must be sought again and again. These are not always present. In the case of stem base rot, the combination of Serenade with Aliette is a very strong duo for combating stem base rot. Three years of research substantiates this conclusion.

Always apply a targeted row treatment at the time of planting and repeat the treatment at an interval of one month or at critical moments. Respect the label regarding number of applications.

Dosage : 7,5 kg/ha Aliette & 5 L/ha Serenade

An additional option is the application of Previcur Energy. In addition to phosethyl (the active substance of Aliette), propamocarb has a direct effect against the fungus by inhibiting the growth of the mycelium. In addition, the zoospores (swarm spores) of the fungus are killed and spore formation and thus the spread of the fungus is strongly inhibited.

Dosage: drip or pour 2.36 L/ha or crop treatment 1.5 L/ha Previcur Energy

Fosethyl-alumimium: trademarks Aliette and Aliette WG
Fosethyl & propamocarb: trademark Previcur Energy
Bacillus amiloliquefaciens QST 713: trademarks Serenade, Serenade OPTI, Serenade MAX, Serenade PRIME