Agronomy - Study Mode
[#646] Hydraulic conductivity of soil is very low in case of
Correct Answer
(D) Alkali soils
Explanation
Solution: Hydraulic conductivity is a measure of how easily water can pass through soil or rock. The value indicates permeable material through which water can pass easily while low values indicate that the material is less permeable. Hydraulic conductivity of soil is very low in the case of Alkali soils.
[#647] The minimum and maximum temperatures for a crop on a given day are 13°C and 30°C, respectively. Calculate the Growing Degree Days (GDD) for the day if the base temperature for the crop is 5°C.
Correct Answer
(C) 16.5
Explanation
Solution: Growing degree days are also known as growing degree units are a heuristic tool in phenology. It is a measure of heat accumulation to predict plant and animal development rates such as the date that a flower will bloom, or a crop will reach maturity. It is calculated by subtracting the plant’s lower base or threshold temperature of 50degree Fahrenheit from the average daily air temperature. Here, $$left[ {frac{{left( {13 + 30}
ight)}}{2}}
ight] - 5 = 16.5$$
[#648] The fruit of rapeseed and mustard is known as
Correct Answer
(C) Siliquae
Explanation
Solution: Rapeseed and mustard are leguminous plants, that belong to the Brassicaceae family. The seed pods of rapeseed and mustard are called as Siliquae . It is eventually green in colour but after ripening turn to brown colour.
[#649] The "miracle plant" useful for fuel, fodder and manure
Correct Answer
(D) Leucaena leucocephala
Explanation
Solution: Leucaena leucoephala is a small fast growing tree, also called River tamarind, Jumbay, White popinac is widely used for a variety of purposes like Fencing, firewood, fiber, livestock fodder as well as manure to increase soil fertility. That is why it is also called a Miracle plant .
[#650] The herbicides containmg carbon and hydrogen in their molecule are called
Correct Answer
(C) Organic herbicide
Explanation
Solution: Organic herbicides are the substances prepared from living wastes like plants essential oils etc. and it does not affect our environment they just act on the applied plant. Organic herbicides use active ingredients like Acetic acid, Citric acid, Clove oil, lemongrass oil, Citrus oil, etc. which contain carbon and hydrogen in their molecules.