How do biotic and abiotic factors affect crop production ?

Explanation

Under natural conditions, the crop plants are prone to certain biotic (diseases caused by bacteria, fungi, virus, nematodes etc. or damage caused by insects) and abiotic (drought, salinity,water logging, heat, cold, etc.) stresses which cause a great loss of production.
Combination of biotic and abiotic factors can causes certain affects on crop :
(a) Increase incidence of insects infestation
(b) Weight loss
(c) Poor germination ability
(d) Degradation in quality
(e) Discolouration
(f) Poor market price