Ear and Grain Mold Holt Boyd Extension Podcast

Ear and Grain Molds - October 5, 2023 - Amy Timmerman - Extension Educator

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• [0:00] This is Amy Timmerman with Nebraska Extension.
• [0:04] With the variable stresses such as drought, hail, wind
• [0:07] and insect damage that occurred this growing season,
• [0:10] for corn grain molds are of major concern as we move into harvest.
• [0:14] Scouting is recommended to determine the extent of ear rot damage
• [0:18] prior to harvest so action can be taken to minimize its impact on grain quality.
• [0:23] Ear and grain molds can reduce the quality of grain and,
• [0:26] under the right conditions, may lead to the accumulation of mycotoxins.
• [0:30] There are several ear molds we can experience in the field including
• [0:34] Diplodia Ear Rot which is caused by a fungus
• [0:37] that can significantly reduce grain quality.
• [0:40] Extensive fungal growth usually begins at the base of the ear and
• [0:43] can overtake the entire ear creating a lightweight mummified ear.
• [0:48] Fusarium Ear Rot can infect any part of the ear and
• [0:52] takes advantage of wounds created by insects or hail.
• [0:55] Fusarium ear rot is favored by a wide range of environmental conditions
• [0:59] and can be identified on the ear by scattered tufts of mold that can be
• [1:03] white to pink in color and accompanied by starburst patterns on the kernels.
• [1:08] Gibberella Ear Rot is commonly recognized by
• [1:11] the red or pink discoloration of the kernels and the
• [1:14] red or pink mycelium growing around the kernels.
• [1:17] Typically, infections begin at the tip of the ear.
• [1:20] Gibberella ear rot infections are favored by cool, wet weather
• [1:24] after silking and through the late summer.
• [1:26] Penicillium Ear Rot can cause a
• [1:29] discoloration of the embryo known as “blue eye”.
• [1:32] This disease is particularly a storage problem and
• [1:35] is favored by high moisture levels in grain bins.
• [1:38] This disease can be managed by reducing
• [1:40] ear wounds caused by insects in the field and
• [1:43] by maintaining low moisture while the grain is in storage.
• [1:47] And finally, Aspergillus Ear Rot which is favored by hot, dry weather
• [1:51] during the latter half of the growing season after
• [1:54] pollination especially favors aflatoxin production.
• [1:58] Drought-stressed corn, such as that in non-irrigated fields
• [2:02] and the corners of fields are out of range of center pivots,
• [2:05] are especially vulnerable to the accumulation
• [2:07] of aflatoxin and aspregillus.
• [2:10] Drying grain prior to storage will slow the growth of fungi in the bin
• [2:15] that can seriously reduce grain quality and accumulate mycotoxins.
• [2:20] Ear rot pathogens may continue to grow during storage
• [2:24] and lead to grain mold that can seriously reduce
• [2:26] grain quality and lead to major deductions at the elevator.
• [2:29] Even under the best growing conditions,
• [2:31] grain molds will continue to grow and,
• [2:34] in some cases, may take over the entire bin.
• [2:37] In southcentral Nebraska losses have been reported up to 30%
• [2:42] when grain was removed from storage, especially after a mild winter.
• [2:46] Even during cold winters, conditions inside the bin
• [2:49] may be very different from their surroundings.
• [2:51] Temperatures inside the bin may take several weeks
• [2:54] to stabilize and condensation may develop,
• [2:56] adding unwanted moisture that promotes fungal growth.
• [3:00] To minimize losses due to grain molds: We need to
• [3:04] 1. Avoid further damage to kernels during harvest and handling.
• [3:08] 2. When possible, avoid storing grain from fields
• [3:11] with a high incidence of ear rot diseases.
• [3:13] 3. If storage is necessary, store for a minimum amount of time.
• [3:18] 4. Dry grain to less than 15% moisture within
• [3:21] 48 hours of harvest to slow further growth of fungi.
• [3:27] 5. Remove old grain from empty bins because it
• [3:29] harbors fungi that can infect new grain.
• [3:32] And 6. Stir and aerate bins during
• [3:35] storage to prevent the development of hot spots.
• [3:38] This has been Amy Timmerman with Nebraska Extension