Plant Pathology - Study Mode
[#771] In 1845, the late blight of potato destroyed the potato crop of Ireland was caused by
Correct Answer
(A) Phytophthora infestans
Explanation
Solution: In 1845, the late blight of potato destroyed the potato crop of Ireland was caused by Phytophthora infestans. Late blight, also called potato blight, disease of potato and tomato plants that is caused by the water mold Phytophthora infestans. The disease occurs in humid regions with temperatures ranging between 4 and 29°C. The infection is caused by the zoospores found in the soil or that fall onto the tubers from infected foliage during harvest. Following germination, the zoospores penetrate the tubers through the "eyes", lenticels, growth cracks, wounds, or via the point of attachment to the plant.
[#772] Which of the following is a biofertilizer?
Correct Answer
(A) Green algae
Explanation
Solution: Green alga is a biofertilizer. Blue-green algae (BGA) are an easily available and economically cheap resource material for production and use as biofertilizers. These are free-living, photoautotrophic micro-organisms, many of which also fix atmospheric nitrogen and are found in abundance in rice fields.
[#773] Most common 5 deficient nutrients in soils are N, P, K, S and
Correct Answer
(B) Zn
Explanation
Solution: The most common 5 deficient nutrients in soils are N, P, K, S and Zn. There is a total of 17 essential nutrient elements required by plants for their growth and development, which are further classified as macronutrients which are required in large amounts, and micronutrients which are required in fewer amounts. The most common 5 deficient nutrients in soils are Nitrogen, Phosphorus, Potassium, Sulphur and the other one is Zinc. These nutrients are most commonly added as fertilizers to plants.
[#774] Which one is an essential mineral, not constituent of any enzyme but stimulates the activity of many enzymes?
Correct Answer
(B) K
Explanation
Solution: K is an essential mineral, not a constituent of any enzyme but stimulates the activity of many enzymes. Potassium is associated with the movement of water, nutrients and carbohydrates in plant tissue. It's involved with enzyme activation within the plant, which affects protein, starch and adenosine triphosphate (ATP) production. The production of ATP can regulate the rate of photosynthesis.
[#775] The stage-I of a rust pathogen consists of
Correct Answer
(B) Aeciospores
Explanation
Solution: The stage-I of a rust pathogen consists of Aeciospores. Rust fungi are obligate plant pathogens that only infect living plants. Infections begin when a spore lands on the plant surface, germinates and invades its host. Aeciospores from Aecia. These serve mainly as non-repeating, dikaryotic, asexual spores, and go on to infect the primary host.