Hydroponics cannot be used in the commercial production of vegetables such as

(1) Tomato

(2) Seedless cucumber

(3) Lettuce

(4) Pomegranate

(1) Aeration to obtain the optimum growth

(2) Lage vessel

(3) Broader neck

(4) Cotton plugs for funnel adjustment

(1) 105

(2) 35

(3) 44

(4) More than 60

1. There are techniques that are able to detect the minerals even at a very low concentration i.e. 10^-8 g/mL.

2. Some plant species accumulate selenium while others gold.

3. Some plants growing near nuclear test sites take up radioactive strontium.

4. The criteria for the essentiality of an element completely depends upon the amount of the element.

(1) The element must be absolutely necessary for supporting normal growth and reproduction

(2) In the absence of element, the plant is not able to complete their life cycle or set the seeds

(3) The requirement of that element must be specific can be replacable by another element

(4) The element must be directly involved in metabolism

(1) Qualitative properties

(2) Structural properties

(3) Quantitative requirements

(4) Both B and C

(1) Excess of 10 mmole/Kg of dry matter

(2) 20 mmole/g of dry matter

(3) 10 mole/Kg of dry matter

(4) 1 mmole/Kg of dry matter

(1) C

(2) Mg

(3) Ca

(4) Fe

(1) N

(2) O

(3) H

(4) All of these

(1) P

(2) C

(3) H

(4) O