Which factor can negatively affect yield calculations?

The selection of all factors as contributing to negative yield calculations is based on the understanding that each element can disrupt the accuracy and reliability of yield data.

Inconsistent field measurements can lead to discrepancies in how yields are recorded, thus affecting the analysis and decision-making process. If measurements vary significantly due to sampling errors or faulty equipment, it becomes challenging to assess true yield potential and performance.

High weed pressure directly competes with crops for nutrients, water, and light, which can drastically reduce potential yields. If weeds are not controlled, they can mask the actual performance of the crop being evaluated, leading to inaccurate yield assessments.

Changes in weather patterns can also greatly influence crop yields. Fluctuations in temperature, precipitation, and extreme weather events can cause crop stress, disease, and other adverse conditions that affect growth and yield. When weather conditions are unpredictable or extreme, they can disrupt the normal yield patterns that growers rely on for planning and crop management.

Therefore, each of these factors—field measurement inconsistencies, weed pressure, and weather changes—contributes to inaccuracies in yield calculations, making the comprehensive answer the most effective choice.