Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

Urea hydrolysis in the soil produces Ammonium carbonate.
The hydrolysis of urea occurs in two stages. In the first stage, ammonia and carbamic acid are produced. The carbamate spontaneously and rapidly hydrolyzes to ammonia and carbonic acid, and produces Ammonium carbonate.
Urea applied to the soil reacts with water and the soil enzyme urease and is rapidly converted to ammonium. In this reaction, hydrogen ions (H⁺) are consumed, causing the soil pH near the fertilizer to rise.

Parthenogenesis is the Development of the embryo from egg without fertilization.
Parthenogenesis is a natural form of asexual reproduction in which the growth and development of embryos occur in a gamete (egg or sperm) without combining with another gamete.
Parthenogenesis means the development of an embryo from an unfertilized egg cell.
Mature egg cells are produced by mitotic divisions, and these cells directly develop into embryos. In flowering plants, cells of the gametophyte can undergo this process.

Cleistogamous flowers are found in Arachis hypogea.
Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers.
The principal advantage of cleistogamy is that it requires fewer plant resources to produce seeds than does chasmogamy because the development of petals, nectar and large amounts of pollen is not required.

a. Badna is a Rice tungro virus.
Rice tungro disease is caused by the combination of two viruses, which are transmitted by leafhoppers. It causes leaf discoloration, stunted growth, reduced tiller numbers and sterile or partly filled grains.
b. Luteo is potato spotted wilt virus.
Dead (necrotic) spots or patches on the leaves. These can appear as concentric rings separated by green tissue, which can lead to confusion with the target spot.
c. Poty is potato virus Y.
Potato virus Y (PVY, genus Potyvirus) is an economically important aphid-transmissible virus with a very wide host range reported in many tomato-growing areas.
d. Tospo is tomato spotted wilt virus.
TSWV, which is transmitted by thrips, causes serious losses in economically important crops and it is one of the most economically devastating plant viruses in the world.

Urea contains 46% nitrogen.
Urea, also known as carbamide, is an organic compound with chemical formula CO(NH₂)₂. This amide has two amino groups (-NH₂) joined by a carbonyl functional group.
Urea is a white crystalline solid containing 46 percent nitrogen as an animal feed additive and fertilizer.
It is a colorless, odorless solid, highly soluble in water, and practically non-toxic.

N. A. Cobb is the father of American Nematology.
Nematology is the scientific discipline concerned with the study of nematodes or roundworms.
Nathan Augustus Cobb, referred to as the "Father of Nematology in the United States", was a Renaissance man and a man of humble beginnings.
Nathan Cobb 1918 published his Contributions to a Science of Nematology and his lab manual "Estimating the Nema Population of Soil."

Syngamy means the fusion of gametes.
Fertilization, also known as generative fertilization, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. The gametes that participate in the fertilization of plants are the sperm (male) and the egg (female) cell.
In flowering plants, two sperm cells are released from the pollen grain, and a second fertilization event involving the second sperm cell and the central cell of the ovule, which is a second female gamete.

The shape of the alfa alfa virus is Icosahedral.
Alfalfa mosaic virus (AMV), also known as Lucerne mosaic virus or Potato calico virus, is a worldwide distributed phytopathogen that can lead to necrosis and yellow mosaics on a large variety of plant species.
The icosahedral symmetry of the capsid is round to elongated. The range for the length of the virion particle is about 30 - 57 nm. AMV is a multipartite virus and is composed of four particles (three bacilliform and one spheroidal) with a diameter of 18 nm.

Hot water treatment of seed is useful for control of Loose smut.
The single-bath hot-water treatments for the control of loose smut in wheat and barley give satisfactory results over a range of time/temperature combinations. Thus the soaking period recommended for wheat ranges from $$1\frac{1}{2}$$ - 2 hr. at 120°F.

A straight fertilizer has one major nutrient.
Straight fertilizers are those which supply only one primary plant nutrient, namely nitrogen or phosphorus or potassium. eg. Urea, ammonium sulphate, potassium chloride and potassium sulphate.
Depending upon the nutrient availability they are further classified as nitrogenous, phosphatic and potassic fertilizers.