1911-12.] BOTANICAL SOCIETY OF EDINBURGH 



The fungi, bacteria, and insect enemies of cultivated 

 plants cause enormous damage and annual loss, not only to 

 the cultivators of plants, but to the nation as a whole. 



In Prussia the Phytopathological Commission gave in 

 1893 a striking example of the loss caused by grain-rust. 

 The data were supplied by the Prussian Statistical Bureau, 

 so that the figures are official. In 1891 the wheat harvest 

 amounted to 10,547,168 doppelcentner. which at 22 marks 

 per dc. would have amounted to £11.459. 600. but 3.316.059 dc. 

 or £3,595,758, fell to be deducted through depreciation by 

 rust. From the rye harvest had to be deducted £8,896,364. 

 Similarly. from the oat harvest had to be deducted £8.138.023. 

 Hence the loss on a single harvest of wheat, oats, and rye 

 amounted to £20,628,147. In Australia the loss in wheat 

 in 1891 caused by rust was estimated at £2.500.000. 



The coffee-leaf disease of Ceylon caused by the fungus 

 Heinilti'i was stated by Professor Marshall Ward to have 



st Ceylon over a million pounds per annum for several 

 years. He further states in his book on 1' - - m Plants 

 that one estimate puts the loss in ten years at from 

 £12,000,000 to £15,000,000. He further states that the 

 Hop Aphis is estimated to have cost Kent £2,700,000 in 

 the year 1882. If the recent outbreak of gooseberry mil- 

 dew of the American type had not been scheduled under 

 the Destructive Insect and Pest Act. and arrested, it would 

 no doubt have wiped out the gooseberry crop throughout 

 the country. Mr. E. S. Salmon states that the average 

 annual value of the gooseberry crop in Kent. Wisbech. 

 Evesham. Calstock. and Gloucestershire is from £97.000 

 .160,000 in these districts alone. Also, that the value 

 of the gooseberry crop to cottagers, private gardeners, etc . 

 is incalculable. It was principally through his energy and 

 influence that the disease was scheduled. 



At the British Association this year Messrs. Barker and 

 Hillier described a disease known as Cider Sickness, that 

 causes a loss probably amounting to several thousand 

 pounds sterling each year in the West of England alone. 

 It is brought about by a bacterium. 



A destructive bacterial disease of the banana and plantain 

 has recently been discovered in the West Indies. The 

 disease causes the leaves to become yellow and drop off. 



