Now it is time to see how much you have learned.

In the following pictures, you need to: describe the symptom, and determine if this is --

• bacterial
• fungal
• viral
• an abiotic or non-pathogen-induced problem

Remember that control measures are routinely available for many diseases and once a problem has been pigeon-holed into one of these four categories listed above, similar control measures exist for many problems in that category.

Fig. 77.  Host -- snap bean.

Fig. 78.  Host -- cucumber.

Fig. 79.  Host -- tomato.

Fig. 80.  Host -- mango.

Fig. 81.  Host -- tomato.

Fig. 82.  This strawberry plant is in the middle of a patch that shows a definite damage gradient from East to West (most severe damage at eastern end, no damage at western end). What caused it?

Fig. 83.   Host -- snap bean.

Fig. 84.  Bean pods.

Fig. 85.  Host -- tomato. 

Fig. 86.  Host -- tomato.  See Fig. 87, below, for a hint. 

Fig. 87.  A cut stem from one of the above plants placed in water.  

Fig. 88.  What happened to these tomato plants?

Fig. 89.  What may have caused this problem on avocado fruit?

Fig. 90.  What is the peculiar symptom seen at the base of this potted sunflower?

Fig. 91. What is the symptom evident on the mango flower cluster on the right?  What is the cause?

This is the last quiz question!

Fig. 92.  Note the more or less circular to oval area of dead plants in the middle of a tomato field. This problem appeared literally almost overnight around October 1st in southern Florida. The area is not low. All the other plants are perfectly healthy. All cultural practices are the same as those normally used.

Hopefully, this Web tutorial has sharpened your plant disease diagnostic skills and made you more aware of the role of plant diseases in the framework of plant health.