An Irish potato farmer in a swampy area had his garden flooded for a long time during prolonged rain experienced in the area. He made the following observations about his garden during the season:
* The leaves of the potato plants turned yellow
* The potato plants became stunted with weak stems
* Some potato plants wilted; others had rotten roots
When the rains reduced and the flooding was no more, the Irish potato plants revived, having greener leaves, upright stems, and numerous roots. The plants managed to produce Irish potatoes for the farmer.
Task
(a) Explain the observations made by the farmer during the rainy season.
(b) How did the potato plants finally manage to produce Irish potatoes for the farmer?
Answer (2)
The farmer observed yellow leaves, stunted growth, and wilted plants due to waterlogging, which caused oxygen deprivation and root rot. When the flooding lessened, oxygen returned to the soil, roots recovered, and the plants revived, allowing them to produce Irish potatoes. This recovery was essential for the plants to regain health and yield a harvest.
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During the rainy season, when the Irish potato farmer's garden was flooded, the plants experienced several adverse effects due to the excessive water:
(a) Explanation of Observations During the Rainy Season:
Yellow Leaves: The potato plants' leaves turned yellow, a condition known as chlorosis, which usually occurs due to a lack of oxygen in the soil. Flooded soil has reduced oxygen because water displaces the air in the soil, depriving roots of the oxygen needed for respiration and nutrient uptake.
Stunted Growth and Weak Stems: The stunted growth and weak stems were likely due to waterlogged conditions that hinder the uptake of essential nutrients and oxygen. Without these nutrients, the plants can’t grow properly or support healthy stem development.
Wilting and Rotten Roots: Normally, wilting is associated with water shortage; however, in this case, it happened despite the excess water because the roots were unable to function correctly under anoxic (oxygen-deprived) conditions. Prolonged flooding can cause root rot, where roots begin to decompose due to fungal and bacterial infections in soggy, airless environments.
(b) Survival and Production Post-Flooding:
Once the rains subsided and the flooding ended, several factors contributed to the recovery of the potato plants:
Oxygen Availability: As the water receded, more oxygen became available in the soil, allowing the roots to respire normally.
Improved Root Function: With aerated soil conditions, the roots could begin functioning again, allowing them to take up water and essential nutrients efficiently.
Photosynthesis Recovery: The emergence of greener leaves indicates that the plants regained their ability to photosynthesize effectively. Chlorophyll production resumed, helping the plants convert sunlight into energy.
Root Regeneration and Growth: The plants developed numerous roots, enhancing water and nutrient absorption, which supported the overall recovery and growth of the plants.
Development of Potato Tubers: With adequate nutrients, oxygen, and energy from photosynthesis, the plants were able to complete their life cycle and produce Irish potatoes for the farmer. Tubers are storage organs, and their formation is key for plant reproduction and farmers’ harvest.
In summary, the initial poor conditions due to flooding caused stress to the plants, but they were able to recover and produce once normal soil conditions were restored.
