Choose the biotic factor which can be the reason for decreased plant yield.

Pathogens can be spread from an contaminated plant or plant flotsam and jetsam to a healthy plant. Microorganisms that cause plant infections incorporate nematodes, parasites, bacteria, and mycoplasmas. 

These pathogens ought to be display within the nursery in arrange to set the organize for a disease issue. 

Moving the center to root malady pathogens, they can be present in the nursery in plant flotsam and jetsam, weeds developing beneath the seat, clean coming in from a field or rock carport, sullied devices, stock plants, cleared out over plants ,creepy crawlies etc.