Picture

Problem overview

Summary below - in part - from U New Hampshire Link
Typical problems and typical causal agents

Problem

Physical Damage & missing plants


Leaf color change and reduced size

Color changes with spots or surface growths

Leaf edge burning


Leaf rolling

Spindly plants


Poor growth and stunted plants

Likely cause(s)

Insects
Mechanical damage,
Rodents, other pests

Nutrient


Disease (check for disease present)

Nutrient deficiency, inadequate water, disease

Insects or water stress

Too much nitrogen or plants growing in shade

Low pH and/or poor nutrition and weed competition

Low temperature

Insects and diseases

Inadequate water
 

Possible action(s)

Resistant varieties
Train machine operators
Remove pest habitat

Add nutrient


Resistant varieties


Add nutrient, add water, resistant variety, change planting date

Adequate moisture, planting date

Avoid excessive nitrogen, and
plant in full sun.

Add lime and fertilizer according to soil test. Control weeds.

Plant later or use soil warming
methods such as black plastic.
Plant resistant varieties

Water to keep soil moist (but not flooded) around roots