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.
While not from the official/government source, there are reports that some Amish use GMO seeds â BT corn (From: BBC) and nicotine-free tobacco (From: Wired). Whatâs interesting, this BBC video actually shows a horse drawn carriage with a chemical cistern mounted on the top, used to spray chemicals on the fields.