Observation

Possible implication

Crop rotation

The crop rotation can influence crop management (e.g., planting date, labor availability, inputs, residues, insects & pests, etc.)

Variety

The variety determines the expected crop duration (maturity), photo-period sensitivity, crop height, growth habit, disease and insect resistance, yield potential, drought tolerance and grain quality

Date planted

If a crop is planted early or late, it may be subject to additional rat, bird, insect, disease or environmental (e.g., water, temperature) stresses

Crop stage

Nutrient management depends on crop stage

Certain pests are a problem at particular growth stages.

How was crop planted?

The quality of land preparation and the seed bed affect:

weed pressure.

field leveling and water management.

problems of establishment if there is too much or too little rain during crop establishment.

problems of birds and rats.

Seed source

The source of seed (own, certified, etc) & treatment can greatly influence seed quality (depending on storage, etc.) and thus can greatly influence crop establishment, plant vigor, health and weed pressure.

Land preparation

Poor land preparation can lead to excess weeds, uneven water management and/or problems of crop establishment. If the field has large clods, you can get poor soil-seed contact and poor emergence.

Land leveling

High spots in a field tend to have greater water stress and more weed problems. Low spots may have water sitting problems of  germination and waterlogging.

Missing plants

Missing plants may indicate various problems of crop establishment and/or pests such as soil insects, rats, and/or birds

Lodging

Lodging may indicate excess N, high winds and/or diseases around the base of the plant. Some varieties are more prone to lodging.

Groundcover

A low number of plants tells about crop establishment problems.
Stunted plants or small leaf size suggests water or nutrient stress.

Differences in height or maturity

Differences in height or maturity may indicate mixed varieties, and/or areas of crop stress (e.g., nutrient or water stress)

Are pests (insects, weeds) apparent?

Visible evidence of pests (or their tracks or droppings) are often good indicators of the possible type of damage to expect.

Field moisture status

Evidence of dry or cracking soil and dried or curled leaves indicate water stress

Is crop height uniform and crop healthy and vigorous?

Look for the extent and causes of variation.

Plant part affected

Helps identify the likely cause of the problem.

Pattern of symptom across the field

The pattern of the symptom gives indications of possible cause. See Typical problem patterns and probable cause.

Symptoms

Work through the Identify the problem key to determine the probable cause. Also check Typical problems and causes

Inputs

Input amount and timing can indicate what may be the cause of the problems.