Strawberry fruit have occasionally been observed affected by leather rot on Long Island. Abundant rainfall when warm during fruiting provides ideal conditions. Typical symptom is tough, leathery tissue on fruit. Affected areas are brown on immature fruit and appear bleached on maturing fruit. Internal tissue also becomes discolored. Typically diseased fruit have an unpleasant pungent odor and even unaffected tissue on a diseased fruit tastes bitter. Eventually they dry up forming stiff, shriveled mummies. The pathogen sometimes grows on the surface of fruit forming a while moldy growth as shown in the photograph. Photographs of other symptoms can be found on the internet by searching ‘leather rot image’ and at http://ohioline.osu.edu/factsheet/plpath-fru-09, where there is a lot of information about this disease and its management.
Manage leather rot by planting where soil drainage is good as standing water provides ideal conditions for the pathogen. A sunny location with good air movement is also important. Avoid practices that can cause soil compaction such as running equipment through fields when soil is wet. A thick layer of straw mulch between rows provides a physical barrier between the pathogen in the soil and fruit. Avoid applying too much nitrogen fertilizer as dense foliage dries slowly. Harvest early in day when plants are dry. Remove diseased fruit as the pathogen survives inside over winter.
Applying fungicides is an additional management practice for leather rot in commercial crops. Labeled products include Ridomil Gold, Abound, Aliette, and phosphorous acids.
Please Note: The specific directions on pesticide labels must be adhered to — they supersede these recommendations, if there is a conflict. Any reference to commercial products, trade or brand names is for information only; no endorsement is intended.