Agronomy - Study Mode

[#71] Dead heart and white head damage to rice is caused by
Correct Answer

(D) Stem borer

Explanation

Solution: Stem borer is one of the most common pests of rice. It can cause severe destruction to the field as it infects the central tiller of the plant leading to drying during the vegetative stage. In grown-up plants, whole ear heads become dried and yield chaffy grains which are also called "White Ear" . While in the vegetative stage larva enters the stem and feeds on the growing shoot and causes drying of the central shoot known as "dead heart” .

[#72] Origin of soyabean is
Correct Answer

(D) China

Explanation

Solution: As per many botanists, it is believed that the soybean was first domesticated in central China as early as 7000 BCE. It is a quite ancient crop, that was being cultivated in China, Japan, and Korea for thousands of years. Because of its rich nutrient value, it is widely used in the food industry as well medical sciences also.

[#73] The oil and protein content of groundnut are
Correct Answer

(A) 45% and 26%

Explanation

Solution: As groundnut belongs to the legume family, it is rich in protein and oil content. It is a very nutritious seed that includes 45% oil and 22 - 30% protein along with other minerals and vitamins.

[#74] Which of the following relation is true,
Correct Answer

(A) RGR = NAR × LAI

Explanation

Solution: RGR is the Relative Growth Rate. NAR is the Net assimilation Rate. LAI is the Leaf area Index. Thus, the relative growth rate depends on both the net assimilation rate as well as leaf area index. Light falling on the leaf and absorbed depends on the availability per unit area further influencing the rate of photosynthesis and assimilation ultimately the growth rate of the plant.

[#75] The best suited temperature for growth of sugarcane lies between
Correct Answer

(C) 21° - 27°C

Explanation

Solution: Sugarcane is the commercial crop of tropical countries and can be grown in both tropical as well as subtropical climate. While the best suited temperature for the growth of sugarcane is from 21° to 27° and annual rainfall is between 75 cm to 100 cm.