Which of the above spread plant diseases? (a) 1 and 3 only (b) 3 and 4 only (c) 1, 2 and 4 only (d) 1, 2, 3 and 4
Answer: D
Plant diseases spread through direct transmission (the pathogen is carried externally or internally on the seed or planting material like cuttings, sets, tubers, bulbs etc.) or through indirect transmission (the pathogen spreads itself by way of its persistent growth or certain structures of the pathogen carried independently by natural agencies like wind, water (rain), animals, insects, mites, nematodes, birds etc