Sorghum panicle damage
The damage to sorghum grain can result from a variety of causes, including environmental, biological, and mechanical factors. Here are some common causes:
1. Excessive Rainfall and Humidity
- Pre-harvest sprouting: If sorghum is exposed to rain during its maturation phase, particularly just before harvest, the moisture can trigger grain germination (pre-harvest sprouting) while still on the plant.
- Mold and Fungal Growth: High moisture levels encourage the growth of fungi such as Fusarium, Aspergillus, and Alternaria, which lead to grain rot and mycotoxin contamination.
- Discoloration and Decay: Wet conditions can cause grain discoloration and decay, especially if the moisture persists over time.
2. Pest Infestation
- Insects: Pests such as aphids, caterpillars, or grain borers can damage the grains directly by feeding on them or laying eggs within the grain. Pest damage is often worsened by wet conditions, which create an environment conducive to both insect populations and mold growth.
- Birds and Rodents: Birds and rodents may feed on the grain, especially if harvest is delayed due to weather or logistical issues, leading to both direct grain loss and secondary damage from pathogens.
3. Temperature Stress
- Heat Stress: During grain development, prolonged exposure to high temperatures can cause heat stress, which leads to poor grain filling and shrunken or light-weight kernels.
- Cold Stress: Cold or frost during sensitive growth stages can inhibit grain development, leading to poorly formed grains or reduced yields.
4. Mechanical Damage During Harvest
- Harvest Equipment: Improperly adjusted or maintained harvest equipment can cause kernel cracking, bruising, or grain breakage, making it more susceptible to fungal infections and moisture absorption.
- Handling and Storage: Rough handling, improper drying, or insufficient ventilation during storage can cause grain breakage and facilitate the growth of molds and insects.
5. Soil Conditions
- Waterlogged Soil: Poorly drained or waterlogged soil can damage plant roots, leading to weakened plants and reduced grain production or quality.
- Nutrient Deficiency: Insufficient nutrients, particularly nitrogen and potassium, can lead to weaker plants with less resilient grains, making them more susceptible to environmental damage.
6. Delayed Harvest
- Harvest delays, especially due to weather conditions or logistical challenges, leave grains exposed to environmental factors like rain, pests, and diseases for longer, increasing the risk of damage.
7. Post-Harvest Factors
- Improper Drying: If the grain is not adequately dried after harvest, moisture can lead to fungal growth and grain rot in storage.
- Storage Pests: Insects like grain borers and weevils can infest stored grain, causing direct damage and facilitating fungal infections.
To minimize sorghum grain damage, it is crucial to manage environmental conditions, ensure proper timing of harvest, and implement effective pest control and storage techniques.
■ References
□ Rain devastates Downs sorghum in harvest window
□ Sorghum and Heat Stress
□ Premature Frost Damage to Crops
□ Sorghum producers battle weather to make a crop
□ Sorghum midge update from Southwest Kansas
