29. A farmer growing a particular variety of grape plants in vineyard, observes the following:

(A)Fruit size normally remained small.

(B) Natural seed abortion.

(C) Development of fungal infection as the pedicels are small in size due to which moisture is retained in the bunches of grapes.

Experts suggested spraying gibberellic acid during the fruit development. This treatment would help in getting rid of
(1) A, B and C                   (2) only A and B
(3) only A and C               (4) only B and C

Correct answer: (1) A, B, and C

Explanation:

• (A) Small fruit size: Gibberellic acid (GA) promotes cell elongation and division, which increases fruit size in grapes.

• (B) Natural seed abortion: GA application induces parthenocarpy (seedless fruit formation) by causing seed abortion or reducing pollen germination/fertilization.

• (C) Fungal infection due to small pedicels retaining moisture: GA promotes elongation and enlargement of pedicels and berries, improving air circulation and reducing moisture accumulation, thus helping in disease prevention.

Therefore, spraying GA during fruit development helps resolve all three problems: small fruit size, seed abortion, and fungal infection due to moisture retention.

Option explanation:

• (1) A, B, and C — correct, all issues addressed by GA.

• (2) Only A and B — fungal infection (C) is also helped by GA.

• (3) Only A and C — seed abortion (B) is affected by GA.

• (4) Only B and C — fruit size (A) is also improved by GA.