In the process of corn cultivation, several issues can arise that lead to poor kernel development. These problems include barren ears, where entire sections of the cob have no kernels, or the ear may bend toward the missing side, resembling a banana shape. Some ears may be completely empty at the top, while others might have bare patches at the base or tip. In some cases, only a few scattered kernels appear on the entire ear, leading to significant yield losses. The main causes behind these issues are as follows:
1. **Insufficient Nutrient Supply**: During the critical period of ear development, if the plant does not receive enough nutrients, it can result in poor kernel formation and reduced yield.
2. **Unsuitable Temperature Conditions**: High temperatures above 35°C before and after tasseling can kill pollen, reducing fertilization success. Similarly, low temperatures below 16°C during the grain-filling stage can hinder dry matter accumulation, affecting kernel development.
3. **Water Imbalance**: Corn requires a lot of water from the silking to the flowering stage. Drought during this time, known as "neck drought," can delay tassel emergence or cause tassels to die, leading to poor pollination and an imbalance between male and female flowers.
4. **Rainy Weather During Pollination**: Excessive rain can prevent tassels from blooming properly. Wet conditions can cause pollen to swell, rupture, or clump together, reducing its viability and affecting successful pollination.
5. **Overcrowded Planting**: When corn is planted too densely, air circulation and sunlight penetration are limited, which can impair plant growth and block ear development, resulting in poor kernel set.
6. **Pest and Disease Infestations**: Pests like corn borers, aphids, and armyworms, along with diseases such as leaf spot and smut, can damage the plant’s functional leaves, causing premature aging and increasing the occurrence of barren ears.
By addressing these factors through proper nutrient management, optimal planting density, timely irrigation, and effective pest control, farmers can significantly improve corn yield and reduce the occurrence of barren ears.