Selective exploitation means felling trees of

A. different ages and girths

B. specific ages and girths

C. different girths and same species

D. different girths and different species

Streak disease of crop commonly attacks

A. millet

B. sorghum

C. maize

D. rice

Most viral diseases of plants are transmitted by

A. wind

B. rain

C. insects

D. rodents

Viral diseases of crop plants are best controlled by

A. planting resistant varieties

B. applying fungicides

C. aplying insecticides

D. flooding farmlands

The following problems are likely to be caused by insects except

A. loss of leaves of crop plants

B. rottening of cobs in storage

C. transmission of viral diseases

D. reduction of grains in storage to powder

Weed plants which grow on other plants without deriving nutrients from them are called

A. sedged

B. epiphytes

C. decomposers

D. saprophytes

When a farmland is heavily infested with striga, it may be concluded that the farmland

A. is undergoing drainage

B. had not ben regularly irrigated

C. may have been used for growing guinea corn

D. may have been used for cowpea production

Mulching

A. reduces evaporation of soil water

B. increases soil acidity

C. prevents seedling diseases

D. improves soil texture

An accessory sex gland in a bull is

A. prostate gland

B. pituitary gland

C. thyroid gland

D. pancreatic gland

The most important reason for low livestock population in the rain forest zone is the

A. fast rate at which pasture crops become fibrous

B. shortage of forage crops during the long dry season

C. growth and proliferation of pathogens

D. thick vegetation cover which impedes animal movement