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.
The Bt corn can produce unpredictable toxins and allergens into food plants and therefore into the final product. Also the Bt corn can be considered unstable as the number of copies of an inserted gene changes through later generations of the Bt corn. The low tillage is also a prime spot for a monoculture in the fields. A monoculture is where all of the crops are the same, so with this it is a perfect situation for weeds.
Bacillus thuringiensis (Bt) is a spore forming (flash animation) bacterium that produces crystals protein (cry proteins), which are toxic to many species of insects.t is largely used in agriculture, especially organic farming. Bt is also used in urban aerial spraying programs, and in transgenic crops. To learn more about each of these topics, click on the corresponding link on the left.