Plant Pathology - Study Mode

[#361] Margosa is a highly effective product in reducing root-knot population belongs to
Correct Answer

(B) Azadirachta indica

Explanation

Solution: Margosa is a highly effective product in reducing the root-knot population belonging to Azadirachta indica. Azadirachta indica, commonly known as neem, nimtree, or Indian lilac, also known as Margosa is a tree in the mahogany family Meliaceae. Root-knot nematodes are one of the plant-damaging nematodes in agriculture causing a projected annual yield loss of 12% worldwide. These nematodes burrow into the soft tissues of root tips and young roots and cause the nearby root cells to divide and enlarge. Neem is effective in reducing root-knot nematode population.

[#362] Richest source of nitrogen is
Correct Answer

(A) Dried blood

Explanation

Solution: The richest source of nitrogen is Dried blood. A blood meal is a dry, inert powder made from blood, used as a high-nitrogen organic fertilizer and a high-protein animal feed. N = 13.25%, P = 1.0%, K = 0.6%. It is one of the highest non-synthetic sources of nitrogen. It usually comes from cattle or hogs as a slaughterhouse by-product.

[#363] A photosynthetic organism which does not release oxygen is
Correct Answer

(B) Green sulphur bacterium

Explanation

Solution: A photosynthetic organism that does not release oxygen is a green sulphur bacterium. These bacteria are a phylum of obligately anaerobic photoautotrophic bacteria that metabolize sulfur. Green sulfur bacteria are nonmotile and capable of anoxygenic photosynthesis. They live in anaerobic aquatic environments. In contrast to plants, green sulfur bacteria mainly use sulfide ions as electron donors. They are autotrophs that utilize the reverse tricarboxylic acid cycle to perform carbon fixation.

[#364] Match the following columns: Column I (Rhizobium sp.) Column II (Crops) a. R. lupini 1. Lupine group b. R. trifoli 2. Clover group c. R. japonicum 3. Soybean d. R. mcliloti 4. Alfa-alfa
Correct Answer

(D) a-1, b-2, c-3, d-4

Explanation

Solution: a. R. lupine in Lupine group. They can fix nitrogen from the atmosphere into ammonia via a rhizobium root nodule symbiosis, fertilizing the soil for other plants. This adaptation allows lupins to be tolerant of infertile soils and capable of pioneering change in barren and poor-quality soils. b. R.trifoli in Clover group. Clover or trefoil are common names for plants of the genus Trifolium consisting of about 300 species of flowering plants. c. R. japonicum and Soybean. Soybean plants to get their necessary dose of nitrogen, partner with bacteria called rhizobium japonicum which can convert atmospheric nitrogen into organic forms the plant can use. d. R. mcliloti and Alfa alfa. R. mclloti is an aerobic, Gram-negative, and diazotrophic species of bacteria. S. meliloti are motile and possess a cluster of peritrichous flagella. S. meliloti fix atmospheric nitrogen into ammonia for their legume symbionts, such as alfalfa.

[#365] Which of the following is not cerrectly matched
Correct Answer

(C) Wheat - red rust

Explanation

Solution: A. Mustard - white rust White rust caused by Albugo cruciferarum (Gray) is the most serious disease in rapeseed and mustard and is responsible for considerable yield losses. B. Paddy - brown spot Brown spot is a fungal disease that infects the coleoptile, leaves, leaf sheath, panicle branches, glumes, and spikelets of rice (paddy). C. Wheat - red rust Stem rust, also known as cereal rust, black rust, red rust or red dust is caused by the fungus Puccinia graminis, which causes significant disease in cereal crops. D. Sugarcane - red rot Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to the fungal disease red rot caused by Colletotrichum falcatum. The pathogen attacks sucrose accumulating parenchyma cells of the cane stalk.