Damping of disease of tomato could be controlled by

The most common way of controlling weeds in tree crop plantations is by

Which of the following crops is correctly matched with a disease that affects it?

Soil-borne diseases could be controlled in the nursery by

Use the information below to answer this question.
I. Yellowing of leaves
II. Raised brown spots on the leaves
III. Drying up of leaves
IV. Exudation of gum

The disease of citrus described above is