Plant Pathology - Study Mode
[#326] Photolithotrophs (photoautotrophs) obtain energy from
Correct Answer
(A) Radiations and carbon from inorganic compounds
Explanation
Solution: Photolithotrophs (photoautotrophs) obtain energy from radiations and carbon from inorganic compounds. Lithotrophs are a diverse group of organisms using an inorganic substrate to obtain reducing equivalents for use in biosynthesis or energy conservation via aerobic or anaerobic respiration. The term "lithotroph" was created from the Greek terms 'lithos' (rock) and 'troph' (consumer), meaning "eaters of rock".
[#327] Who proposed the criteria of essentiality of plant nutrients?
Correct Answer
(A) D. I. Arnor
Explanation
Solution: D. I. Arnor proposed the criteria for the essentiality of plant nutrients. D. I. Arnor and Stout proposed the criteria for the essentiality of plant nutrients in 1939. The elements that are considered essential elements in deficiency of which the plant must be unable to complete its life cycle. There are 17 elements classified as essential elements and these are carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, Sulphur, calcium, magnesium, boron, chlorine, copper, iron, manganese, molybdenum, nickel and zinc.
[#328] Clubroot of crucifers are favoured by soil pH
Correct Answer
(C) 5.7
Explanation
Solution: Clubroot of crucifers is favoured by soil pH 5.7. Clubroot of Crucifers is a fungal disease that affects several plants in the cabbage family including cabbages, radishes, mustard and ornamentals such as candytuft. It is caused by the fungus Plasmodiophora brassicae and gets its name from the club-like roots it induces in infected plants. Warm soil (20° - 24°C), high soil moisture and acid soil (pH less than 6.5) are environmental factors that favour infection and severe disease development.
[#329] Di-ammonium phosphate contains
Correct Answer
(A) 46% P 2 O 5
Explanation
Solution: Di-ammonium phosphate contains 46% P 2 O 5 . Di-ammonium Phosphate popularly known as DAP is a preferred fertilizer in India because it contains both Nitrogen and Phosphorus which are primary macro-nutrients and part of 18 essential plant nutrients. DAP (NH 4 ) 2 HPO 4 : Fertilizer grade DAP Contains 18% Nitrogen and 46% Phosphorus (P 2 O 5 ).
[#330] The suitable fertiliser for foliar spray is
Correct Answer
(B) Urea
Explanation
Solution: The suitable fertilizer for the foliar spray is Urea. Foliar fertilizers are dilute fertilizer solutions applied directly to plant leaves. As with soil application of fertilizer, the goal of foliar fertilization is to supply plants with the nutrients needed for good growth. Urea is commonly used for foliar fertilization because of its uncharged, high solubility and it's rapid and efficiently absorbed by leaves. Once urea is absorbed, it's changed into ammonia and carbon dioxide by a chemical called urease, found in the leaves of many plants.