Question

Tylenchulus semipenetrans can be managed by using trifoliate orange as a:
(A) Root-stock
(B) Biofumigant
(C) Donor parent in hybrid production
(D) Trap crop
Choose the correct answer from the options given below:

• A. (A) and (B) only
• B. (B) and (D) only
• C. (A), (B) and (C) only
• D. (A) and (C) only

Hint:

For nematode control, root-stock resistance and biofumigation are sustainable integrated approaches.

Answer 1

The Correct Option is A

Trifoliate orange is commonly used as a root
stock to manage nematodes like Tylenchulus semipenetrans.
Biofumigants are used to suppress soil
borne pathogens, and the root exudates of trifoliate orange have some biofumigant properties.
It is not used as a trap crop or hybrid donor in this context.

Answer 2

Statement elimination:
(D) Trap crop is ruled out because trifoliate orange is not planted to lure the citrus nematode away from the main crop, it is planted as the main rootstock itself.
(C) Donor parent in hybrid production is also ruled out here since the question is about direct field management, not breeding programmes.
That leaves (A) Root-stock, trifoliate orange is widely used as a nematode-tolerant rootstock for citrus, and (B) Biofumigant, its root exudates have some suppressive effect on soil pathogens.
Hence the correct combination is (A) and (B) only.