A) The processes affected in the plant that led to the decline in the yield are:

a) The processes affected in the plant that led to the decline in the yield are:

• Pollination and fertilization (due to flowers remaining closed or falling off).
• Transpiration (excessive water loss from leaves and flowers).
• Photosynthesis (due to water stress affecting leaf function).

b) The strong wind and heavy sunshine led to a decline in yield through several mechanisms:

• Reduced Pollination and Fertilization: The intense conditions caused flowers to remain closed or fall off. Closed flowers prevent pollinators from accessing them, hindering pollination. If flowers fall off, fertilization cannot occur, directly reducing the number of beans formed.
• Increased Transpiration and Water Stress: Strong wind and heavy sunshine significantly increase the rate of transpiration, leading to excessive water loss from the leaves. This caused the leaves to become wrinkled (wilting), indicating severe water stress.
• Impaired Photosynthesis: Under water stress, plants tend to close their stomata to conserve water. This reduces the uptake of carbon dioxide, which is vital for photosynthesis. A lower rate of photosynthesis means less food production for the plant, resulting in fewer and smaller beans, thus reducing the overall yield.