New Cocoa seedlings

These are cocoa seedlings raised under intensive management for distribution…


Sample physiology of crop plants questions and answers

What’s the effect of thermal stress on leaves?

Causes death of plant

List the three processes through which heat can be removed from leaves.

Re-rediation, transpiration, convection of heat

Early seedling growth is characterized by………..

Slow growth rate.

In the absence of heavy shading, photosynthesis and dry matter production of plants are proportional to the amount of leave area on the plant.

The current commonest way of determining leaf area is by the use of

Photoelectric device

Why do agronomists generally analyze plant community growth?

Because it represents accumulation of economic yield

What’s the impact of leaf area expansion and maximum light interception on crop growth?

It leads to an increase in crop growth rate.

Why is relative growth usually compared with the law of compound interest?

Because the rate of increase is proportional to the initial amount of dry weight present.

What are the two aspect of competition which determines itseffects on yield?

Amount or intensity of competition and time of onset of competition


What is Soil Fertility?

This is the quality that enables a soil to provide the proper nutrients, in the proper amounts and in proper balance, for the growth of specified plants when other growth factors (growth and yield factors) are favorable. In the definition I indicated that for the growth of specified plants because each crop plant has a distinct nutrient requirement and until that requirement is met it growth will not be to it maximum if all other factors are favorable.

It should be noted that a soil can be fertile but not necessarily productive. Thus productivity of a soil is an economic concept not a soil property. Soil productivity then refers to the capacity of a soil to produce a specified plant under a special system of management.

For example two farmers cultivating the same crop say groundnut and using the same soil type ( ie same soil fertility status) may have differences in yield due to the differences in input ie management practices( the productivity aspect). Thus a soil of the same fertility status can be productive for one farmer but not for the others.

Hope my answer was to your requirement. Don’t forget to leave your comments. Thank you.


Growth And Yield Factors

A quantitative consideration of growth and yield laws indicate that maximum growth or yield is acquired when none of the growth factors is present in less amount than what the plants require.

Growth factors can be broadly grouped under genetic factors and environmental factors of course there are other means of classifying growth and yield factors such as

1. Physical, chemical and biological

2. From agricultural viewpoint as controllable and non controllable factors and a typical example is under rain fed agriculture, climatic factors precisely rainfall is non controllable.

But for now let’s focus on the genetic and environmental factors.

Genetic Factors

The significance of genetics in growth of crops is brought to light by the large increases in yield resulting from the usage of improved varieties. It is of essence to know that the genome of a given plant species limits the extent to which that plant may grow and produce, ad these limits can’t be extended no matter how favorable the prevailing environmental conditions.

Environmental Factors

The external conditions that affect the life and growth of plants or crops since we are talking about crops. It is impossible to isolate any component factor of the environment which does not influence another. These components or constituents of the environment can be grouped under the following

Climatic factors- temperature, precipitation, moisture, light etc

Physiographic factors- determined by the general geological strata and topographical features such as relief, slope and erosion.

Edaphic factors- pertaining to the soil eg soil aeration, soil structure etc.

Biotic factors- activities of living organisms.