Even if enough Fe is in the soil, deficiency can occur under the following conditions: poorly drained soil, high Ca, high Mn, high pH, high P, high heavy metals, oxygen deficiency. Deficiency symptoms General: Yellow or white areas on youngest leaves. Older leaves remain green.
Bt corn is a variant of maize that has been genetically altered to express one or more proteins from the bacteria Bacillus thuringiensis. The protein is poisonous to certain insect pests and is widely used in organic gardening. The European corn borer causes about a billion dollars in damage to corn crops each year.
Frost or Freeze Damage to Corn. According to the USDA Soil Survey of Craven County, 5 of 10 years will have temperatures at or below 32O F past April 2nd but only 2 of 10 years will have temperatures this low after April 14th. There is only a 10% probability of having temperatures at or below 28O F past April 6th. Thus, the most probable last frost/freeze event is likely to occur about mid-April in most years. These periodic cold temperatures may cause significant leaf tissue damage to corn but may or may not cause significant yield loss.