Crop Management Flashcards

In integrated pest management (IPM), what is the correct order of pest management tactics by preference?

Answer: Prevention, cultural, biological, chemical

IPM prioritizes prevention first, then cultural controls, biological controls, and uses chemical controls as a last resort.

Which soil water potential range is generally considered optimal for crop water uptake?

Answer: -0.03 to -1.5 MPa

Soil water potential between -0.03 MPa (field capacity) and -1.5 MPa (permanent wilting point) represents plant-available water.

A soybean crop is showing nitrogen deficiency symptoms despite adequate soil nitrogen. Which condition could cause this?

Answer: Waterlogged soils reducing root function and nodule activity

Waterlogged soils kill rhizobium nodules and reduce root function, preventing nitrogen fixation even when soil nitrate is present.

What is the recommended practice when planting corn after corn (continuous corn) to manage northern corn leaf blight?

Answer: Select resistant hybrids and bury residue with tillage

Using resistant hybrids and incorporating residue reduces northern corn leaf blight inoculum, since the pathogen overwinters in infected crop debris.

Which seeding depth is generally recommended for small-seeded crops like alfalfa?

Answer: 0.5 to 1.0 inch

Small-seeded crops like alfalfa have limited seed energy reserves and should be planted at 0.5–1.0 inch to ensure rapid emergence.

What does the leaf area index (LAI) represent in crop physiology?

Answer: Total leaf surface area per unit ground area

LAI is the ratio of total one-sided leaf area to the ground surface area beneath the crop canopy, reflecting light interception capacity.

Which practice best prevents development of herbicide-resistant weed populations?

Answer: Rotating herbicide modes of action and integrating non-chemical weed control

Rotating herbicide modes of action and incorporating mechanical or cultural controls prevents selection pressure that leads to resistance.