Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

The plants produce a whip-like black shoot, often very long and much curved on itself in smut of sugarcane caused by the pathogen Ustilago scitaminea.
Production of whip-like structure (25 - 150 cm) from the growing point of the canes. Whip covered by translucent silvery membrane enclosing a mass of black powdery spores. Initial thin canes with elongated internodes later become reduced in length. Profuse sprouting of lateral buds with narrow, erect leaves especially in the ratoon crop.

Fusaric acid is a vivotoxin.
Vivotoxin designates a secondary metabolite produced by the pathogen and/or its host during infection, produces disease symptoms, but is not oneself the initiating causal agent of the infection.
Out of all, Fusaric-acid is the most studied pathogen-produced wilt toxin classified as a non-specific vivotoxin.

Nitrate can be absorbed by roots as it can be lost by Leaching.
Nitrate can be absorbed by roots as it can be lost by the process of Leaching. Nitrogen can be lost from agricultural lands through soil erosion and runoff.
Leaching is the loss of water-soluble plant nutrients from the soil or applying a small amount of excess irrigation to avoid salinity.

Green light is the least effective in photosynthesis.
Chlorophyll gives plants their green colour because it does not absorb the green wavelengths of white light.
That particular light wavelength is reflected from the plant, so it appears green. Plants that use photosynthesis to make their food are called autotrophs.

The least hygroscopic fertilizer is SSP.
SSP is the most popular phosphatic fertilizer after DAP as it contains 3 major plant nutrients i.e. Phosphorus, Sulphur and Calcium along with traces of other micronutrients.
SSP is a grey to brownish coloured material containing monocalcium phosphate and calcium in almost equal proportions. It is the least hygroscopic but needs moisture-proof packing to avoid lump formation during storage.

Feathery stigma occurs in Wheat/Jowar.
The stigmas are long and feathery, which gives a large surface area for catching pollen.
Feather stigmas are generally found in the Poaceae family and wheat is one of the representatives of this family.
Wheat has feathery stigmas because it is wind-pollinated and feathery stigmas are necessary for capturing the pollen grains.

Photosynthesis occurs in Chloroplasts.
In plants and algae, which developed much later, photosynthesis occurs in a specialized intracellular organelle the chloroplast.
Chloroplasts perform photosynthesis during the daylight hours. The immediate products of photosynthesis, NADPH and ATP, are used by the photosynthetic cells to produce many organic molecules.

The mordant used in Gram staining is Iodine.
The mordant is Gram's Iodine. This binds to the crystal violet making a large complex that adheres to the cell membrane.
Gram's Iodine is allowed to sit for 30 seconds then the decolourizer, 95% ethanol is added.

The potassium element is highly mobile among all the given options.
Potassium is a highly mobile element in the plant and is translocated from the older to younger tissue.
Potassium deficiency symptoms usually occur first on the lower leaves of the plant and progress toward the top as the severity of the deficiency increases.

Stem galls of coriander (Coriandrum sativum) are caused by Protomyces macrosporus.
Stem gall caused by the fungus Protomyces macrosporus L. is a serious disease of coriander damaging all the aerial plant parts incurring heavy losses as the market value is reduced.
In India, the stem gall disease of coriander was reported for the first time from Pusa (Bihar) by Sydow and Butler (1911).