Which of the following conditions can affect fruit set in crops?

High temperatures can significantly impact fruit set in crops due to the physiological stresses they impose on the plants. When temperatures rise above the optimal range for a particular species, several negative responses can occur. For instance, high temperatures can lead to increased rates of respiration and transpiration, effectively reducing the plant's ability to photosynthesize and produce the energy necessary for fruit development.

Additionally, elevated temperatures during the flowering and fruit development stages can disrupt pollen viability and stigma receptivity. This can result in reduced pollination rates, leading to fewer fruits being set. In some cases, extreme heat can cause blossoms to drop prematurely, further reducing the potential fruit yield. These physiological and reproductive stresses highlight why managing temperature conditions is crucial for successful fruit set in specialty crops.

While pest infestation, soil pH, and water availability can also influence fruit set, their effects may vary by crop type and environmental conditions. Pest issues can lead to damage or stress in plants, while improper soil pH can affect nutrient availability, and water stress can impact nutrient uptake and physiological functions. However, the immediate and direct role of high temperatures during critical growth stages underscores why this condition is particularly impactful on fruit set.