Explore how plant growth regulators (PGRs) and plant growth promoters (PGPs) impact cumin cultivation with these targeted, scenario-based questions. Assess key concepts essential for optimizing cumin growth and yield using agricultural inputs.
A cumin farmer applies gibberellic acid as a plant growth regulator; what is its most likely effect on cumin plants?
Explanation: Gibberellic acid is known to promote stem elongation and can induce early flowering in many crops, including cumin. It does not directly induce root rot resistance (a function more connected with biological control or resistant varieties). Gibberellic acid promotes, not delays, seed germination. Leaf chlorosis is unrelated to gibberellic acid application and more often linked to nutrient imbalances.
Why might a cumin grower use plant growth-promoting (PGP) bacteria like Azospirillum during crop establishment?
Explanation: PGP bacteria such as Azospirillum are primarily applied to improve nutrient uptake (like nitrogen) and stimulate root growth. They do not enhance pesticide absorption or intentionally inhibit flowering. Slowing down photosynthesis is not a desirable trait and is not associated with PGP microbes.
At which growth stage is the foliar application of cytokinins considered most beneficial in cumin cultivation?
Explanation: Cytokinins applied during the branching stage can maximize effect on shoot development and branching, supporting higher yield potential. Application at harvest or drying stages is too late for growth promotion. The seed dormancy stage involves seeds before sowing and is not appropriate for foliar PGR use.
A cumin field faces wilt disease; which plant growth-promoting (PGP) fungus is commonly used to improve disease resistance and plant vigor?
Explanation: Trichoderma is well-known for promoting plant vigor and enhancing resistance against soil-borne diseases, including wilt, in cumin. In contrast, Phytophthora and Fusarium are commonly disease-causing fungi. Penicillium is not typically associated with disease resistance in this context.
What is a possible consequence of over-applying synthetic PGRs in a cumin crop?
Explanation: Excessive application of synthetic PGRs can disrupt natural hormonal balance, leading to abnormal growth, poor flower development, or reduced seed set in cumin. Uniform yield increase and enhanced pest resistance are not guaranteed--overuse can even be harmful. There will usually be an effect rather than no change when overdosed.