Page 500 - FRUTAS DEL TRÓPICO

500 Frutas del trópico

unavailable for plant uptake. High concentrations of bicarbonate in the soil solution can pre-
vent Fe uptake by the plant, as well as its translocation within the plant. Most tropical fruit crops

are susceptible to Fe deficiency. Chelated Fe (Fe-EDDHA) is commonly used for fruit trees.

Some iron-efficient crops release organic acids from their roots to neutralize the bicarbonate

and to mobilize soil Fe. Other iron-efficient crops possess high Fe-reductase activity, or other

superior physiological and biochemical characteristics. Application of EDDHA chelated Fe is

commonly practiced to improve the Fe nutrition of both fruit and vegetable crops. Generally, it

is applied as a soil drench (water plus iron) or through the microirrigation system (fertigation).

Zinc (Zn) and Manganese (Mn): The solubilities and availabilities of Zn and Mn are very

low in calcareous soils. However most vegetable crops have the ability to take up sufficient
quantities of both Zn and Mn. Applications of fungicides containing Zn and Mn also provide

available Zn and Mn to plants. Nevertheless, deficiencies of Zn and Mn are very common in

crops grown on calcareous soils. Foliar applications with Zn and Mn fertilizers can effectively

correct these deficiencies.

Soil testing and plant analysis

It is impossible to diagnose plant deficiency accurately just based on visual evaluation, except

for severe cases. Soil testing and plant analysis should be utilized for nutrient management.

However, understating the limitations of these evaluation tools is very important for proper

use. This will be discussed in detail in my lecture.

Universidad Autónoma de Chiapas