Summer Almond Disease Control

luna healthy from nut development to harvest image of almonds

Prepare Your Orchard for Summer Diseases

Click to learn about the benefits of Luna in almondsThe summer season brings warmth and humidity to California’s almond orchards, making them more susceptible to summer diseases such as Alternaria leaf spot, Rust and Hull rot.

With cultural practices changing, canopies are denser allowing for less sunlight penetration. Even when the orchard is not being irrigated and with or without rain, humidity is high, creating a favorable environment for fungal diseases.

Protect Your Almonds with a Highly Effective Fungicide

Trust Luna® to protect your almonds from the most common summer diseases.

Luna Sensation® and Luna Experience® are top-rated fungicides with excellent and consistent control of Alternaria leaf spot and Rust, and with good and reliable Hull rot suppression according to the UC Fungicide Efficacy for Almond Diseases Guide.

Chart showing the Luna Experience and Luna Sensation efficacy of summer diseases in almonds

Source: 2017 UC Almond Fungicide Efficacy and Treatment Timing UC IPM Online. Acknowledgment: Adaskaveg et al., 2017. Efficacy and Timing of Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry and Vine Crops.


Common Summer Almond Diseases: Risks, Symptoms and Treatment


  • RISK FACTORS: Favors dew and high humidity coupled with stagnant air.
  • SYMPTOMS & SIGNS: Large brown spots on leaves turning black as the disease progresses and the fungus produces spores.
  • RECOMMENDED TIMING: Apply Luna during nut development for outstanding control of Alternaria compared to other premium fungicides.                   
Bar chart to show trial data Luna Experience provides outstanding control of Alternaria leaf spot in comparison to other premium fungicides


  • RISK FACTORS: Favors humid conditions and escalates in the late spring and summer rains. The disease requires a shorter duration of leaf wetness to infect, and spores can spread to neighboring orchards by air movement.
  • SYMPTOMS & SIGNS: Appears as small, yellow spots on the upper surface of the leaves and as rusty, red spots on the underside of the leaves. The disease survives from season-to-season, and if not controlled, it can weaken trees, reducing the following year’s bloom.
  • RECOMMENDED TIMING: Apply Luna in the late spring and summer during nut development to control the symptoms of Rust. 


  • RISK FACTORS: Favors humid conditions, irrigation and excess nitrogen from the beginning of hull split until the hulls dry.
  • SYMPTOMS & SIGNS: Hull rot is caused by two fungi, Monilinia spp. or Rhizopus stolonifer. These fungi can cause leaf and shoot die-back and create a brown area on the outside of the hull. Within the brown area is either a tan fungal growth on the outside of the hull, indicating Monilinia spp., or a black fungal growth on the inside of the hull, indicating Rhizopus stolonifer. Infected fruit may not fall during harvest, and if not removed, can also provide overwintering sites for navel orangeworm (NOW).
  • RECOMMENDED TIMING: Apply Luna Sensation® at hull split to suppress hull rot caused by Rhizopus stolonifer by integrating it into deficit irrigation practices. For control of hull rot caused by Monilinia spp., apply Luna three to four weeks before hull split.

Aproach is a registered trademark of E.I. DuPont. Syllit and PH-D are registered trademarks of Arysta LifeScience. Merivon is a registered trademark of BASF. Always read and follow label instructions.

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To avoid the short- and long-term damage caused by Alternaria and help drive optimal return on investment, it is important for almond growers to monitor their crops and implement prevention and treatment best practices.// more
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