Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

The composition of Bordeaux paste is 1 kg Copper sulphate + 1 kg lime + 10 kg gallon water.
Bordeaux mixture is a combination of copper sulphate, lime, and water and is an effective fungicide and bactericide that has been used for decades to control diseases of fruit and nut trees, vine fruits and ornamental plants.
The original formula developed by Millardet contains 5 lbs of CuSO₄ + 5 lbs of lime + 50 gallons of water.
The ultimate mixture contains a gelatinous precipitate of copper hydroxide and calcium sulphate, which is usually sky blue. Cupric hydroxide is the active principle and is toxic to fungal spores.

The smut of pearl millet (caused by Tolyposporium penicillariae) is soil-borne.
Smut of pearl millet (Pennisetum glaucum), caused by Tolyposporium penicillariae, is an important and widespread disease.
It causes direct loss of grain by replacing them with smut sori, and yield losses of up to 30% have been reported.
Soil-borne plant pathogenic fungi cause a variety of diseases, such as root rot, stem rot, crown rot, damping-off, and vascular wilts, resulting in significant economic losses in the yield and quality of agricultural and horticultural crops worldwide.

When a disease spreads to the whole of plants, it is termed Systemic.
Systemic symptoms are those involving the reaction of a greater part or all of the plant, such as wilting, yellowing and dwarfing.
In this, the pathogen spreads throughout the plant body and is associated with almost every stage of the plant's life cycle.

Enzymes occur in the cell in the form of Colloids.
Cells contain thousands of different enzymes, and their activities determine which of the many possible chemical reactions take place within the cell.
The colloidal state is a particulate phase, in which the particles range in. size from 1.0 nm to 10' nm, dispersed in a continuous phase, the dispersion medium.

One of the most resistant biological materials is Sporopollenin.
Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains. It is a highly cross-linked polymer composed of carbon, hydrogen, and oxygen that is extraordinarily stable.
It is formed from the polymerization of carotenoids, is chemically very stable, and is resistant to almost all kinds of environmental damage.

Respiration can occur in the absence of oxygen in Yeast.
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom.
Yeasts are aerobic and facultatively anaerobic. Some yeasts are extremely aerobic and oxidative in their metabolism.

Photorespiration in C₃ plants starts from Phosphoglycolate.
Photorespiration refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. The oxygenation reaction of RuBisCO is a wasteful process because 3-phosphoglycerate is created at a lower rate and higher metabolic cost compared with RuBP carboxylase activity.
PGA is the normal product of carboxylation and productively enters the Calvin cycle. Phosphoglycolate, however, inhibits certain enzymes involved in photosynthetic carbon fixation.

Propoxur is Carbamate.
Propoxur (Baygon) is a carbamate non-systemic insecticide introduced in 1959 with a fast knockdown and long residual effect used against the turf, forestry, and household pests and fleas.
Carbamate insecticides kill insects by irreversibly inactivating the enzyme acetylcholinesterase. It is also used in pest control for other domestic animals, Anopheles mosquitoes, ants, gypsy moths, and other agricultural pests.

Citrus greening is caused by Fastidious bacteria.
Citrus greening disease is a disease of citrus caused by a vector-transmitted pathogen. The causative agents are motile bacteria. The causative agents are fastidious phloem-restricted, Gram-negative bacteria in the gracilicutes clade.
The disease is vectored and transmitted Needham made the 1^st report of nematode associated with plant disease in 1943 by the Asian citrus psyllid, Diaphorina citri, and the African citrus psyllid, Trioza erytreae, also known as the two-spotted citrus psyllid.

Needham made the 1^st report of nematode associated with plant disease in 1943.
Turbevil Needham accidentally recorded the first plant parasitic nematode when he crushed one of the shrunken and blackened wheat grains and observed “Aquatic worms, Eels, or Serpents, which they very much resemble.” He named it Vibrio tritici. Later this nematode was rightly named Anguina tritici by Steinbuch.
From 1750 to the early 1900s, Nematology research continued to be descriptive and taxonomic, focusing primarily on free-living nematodes, and plant and animal parasites.