Question

Match herbicides with their first use/testing or synthesis

Herbicide	First synthesis/use/testing
(A) Glyphosate	(I) 1995
(B) 2, 4-D	(II) 1971
(C) Diclosulam	(III) 1958
(D) Atrazine	(IV) 1944

Choose the correct answer from the options given below:

• (A) - (IV), (B) - (III), (C) - (II), (D) - (I)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Recall that 2,4-D and atrazine are much older herbicides than glyphosate and diclosulam.

Answer 1

The Correct Option is B

This question asks us to line up four herbicides with the year each was first synthesised, tested, or brought into use, using known milestones in herbicide history.

1. Glyphosate: Its weed killing action was found by John Franz in 1970, and this was followed by field testing in 1971, years ahead of its commercial launch in 1974, so it pairs with 1971.
2. 2,4-D: This is one of the very first selective synthetic herbicides, first made and tested around 1944, before it reached farmers commercially a couple of years later, so it pairs with 1944.
3. Diclosulam: A sulfonamide herbicide developed much later than the others, first introduced around 1995, so it pairs with 1995.
4. Atrazine: A triazine herbicide first synthesised in 1958, which later became a mainstay for weed control in maize, so it pairs with 1958.

Lining these up gives Glyphosate with 1971, 2,4-D with 1944, Diclosulam with 1995, and Atrazine with 1958, which is exactly option 2, (A)-(II), (B)-(IV), (C)-(I), (D)-(III).

Let's summarize:

• 2,4-D (1944) and atrazine (1958) are much older herbicides than glyphosate (1971) and diclosulam (1995).
• Matching each compound to its correct era gives option 2 as the answer.

So the final answer is option 2.