By Andi Anderson
Chestnut brown rot, primarily caused by the fungus Gnomoniopsis smithogilvyi, has emerged as a major concern for chestnut producers globally. This pathogen leads to the browning and decay of chestnut kernels, adversely affecting both yield and marketability.
The disease cycle begins with the fungus overwintering in fallen plant debris. In spring and summer, spores are released, spreading through rain splash, wind, and insects, infecting flowers, leaves, and developing nuts.
Notably, the fungus can exist asymptomatically within plant tissues, becoming pathogenic under favorable conditions such as high humidity and optimal temperatures.
Recent studies have identified effective fungicide treatments. Laboratory tests indicate that fungicides containing difenoconazole and pyraclostrobin significantly inhibit fungal growth.
Field trials suggest that applying these fungicides during early bloom, followed by a second application two weeks later, effectively suppresses disease development. A third application during nut ripening may further reduce infection, especially in orchards with high disease pressure.
Biological control agents, such as Bacillus amyloliquefaciens and Trichoderma atroviride, have also shown promise in inhibiting the growth of G. smithogilvyi. These agents can be integrated into management practices to enhance disease control.
In addition to chemical treatments, maintaining orchard hygiene is vital. Regular pruning, proper fertilization, and the removal of fallen debris can reduce the sources of infection. Prompt harvesting and minimizing the time nuts spend on the ground can also decrease the risk of contamination.
Post-harvest, storing chestnuts at low temperatures and maintaining a consistent cold chain during distribution are essential to prevent disease progression.
Implementing these integrated management strategies can significantly mitigate the impact of chestnut brown rot, ensuring healthier orchards and improved crop quality.
Photo Credit: gettyimages-alexeyrumyantsev
Categories: Michigan, Rural Lifestyle, Farm Safety