Agronomy MCQ Question and Answer | Agriculture MCQ Question

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”.

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.

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.

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.

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.

Soil organic carbon is a measurable component of soil organic matter. Organic matter makes up just 2 - 10% of most soil's mass based on composition. While carbon is the main constituent of organic matter and it plays important role in enhancing the fertility, water retention capacity and texture of the soil. Approximately 0.51% of carbon in organic matter can be considered as medium availability.

The optimum seed rate of castor plantations is approximately 18 - 20 kg/hectare for the desired population. Plant population and arrangement in the cropping system should be properly designed to maximize the seed yield of short height genotypes of castor.

The Law of optima or the law of limiting factors has been proposed by Blackman in 1905. This law comes into effect when any biochemical process in any organism is affected by several factors. This law states that if a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value.

Topping and desuckering is a practice widely used on a tobacco plantation. The main aim of this practice is to divert the energy and nutrients from flowers to the leaves, to increase the leaf size and its quality because tobacco yield is dependent on leaf quality and quantity.

Dolma is the husk with less variety of barley. This variety is quite suitable to be grown in rain-fed and hilly areas of Himachal Pradesh and Uttarakhand. It is fairly resistant to yellow rust. Its life cycle is 140 - 150 days.