4 RUST AND MILDEW IN INDIA. 



we see that it ranges from an annual minimum loss of one- 

 hundredth part of the possible produce, through 20 per cent, (in 

 Japan) atid 50 per cent, (a general estimate in some regions), to 

 complete loss in years of exceptional visitation. It will be interest- 

 ing, with these data, to consider the possible and probable financial 

 loss occasioned by the parasite in India. Basing our calculation on 

 the very low estimate given by Bolley for Indiana, namely, one- 

 hundredth part of the crop, we arrive at the following results : — 

 The estimated outturn of wheat during the year 1888-89, for the 

 whole of India, was 6,510,797 tons, raised from 26,508,000 acres, 

 and the value of this crop, at the rates adopted in the Inland Trade 

 Returns, is Bs. 410,191,677- If rust and mildew are prevalent 

 throughout the wheat-producing areas of India, then the least loss 

 occasioned by it may be set down with comparative certainty at 

 Rs. 4,000,000 annually. But as I have no direct evidence that rust 

 is universally present throughout India, I would prefer to estimate 

 the loss which is probably sustained in those parts of India in 

 which I know that the disease certainly exists, namely, in the 

 Punjab, North-Western Provinces and Oudh, Central Provinces 

 and Berar. In these parts, the average area under wheat cultiva- 

 tion during the four previous years was 16,734,000 acres, and the 

 outturn of wheat in 1888-89 was 4,354,869 tons. This was 

 valued at Rs. 296,152,594, and a loss of one-hundredth means a 

 loss of nearly three millions of rupees annually to the wheat 

 producers of the area. I think there is no doubt whatever that 

 this loss is considerably under-estimated, and that it is much more 

 likely to be five times as great. My reason for making this last 

 statement is based upon certain direct observations made upon the 

 pernicious effect of the parasite on individual plants. The contrast 

 between grains of wheat # taken from perfectly healthy plants and 

 those taken from mildewed plants is very striking, and I have 

 attempted to show this in figures 10-13, from a photograph; but as 

 this does not convey any accurate idea of solidity, I have so 

 arranged it that the groups of grains represented are of equal 

 weight. - The healthy grains, and those taken from plants that had 

 been attacked by Puccmia graminis (Rolli), were received from 

 Jeypore, already cleaned from the ear. I placed ten of the former 

 into one pan of a pair of scales, and found that they required from 

 26 to 36 grains of the latter to balance them, or, on the average of 

 several weighments, 30 grains. We have here then a loss of 

 200 per cent, in the case of individually attacked plants. The 

 samples of P. rnbigo I received from Jeypore had not their grains 

 taken out. I did this myself, however, and from two ears (which 

 to outward appearance were as full-looking as healthy ears) I 

 obtained only thirty-seven miserably shrivelled-up grains, which 

 were equal in weight to only four sound grains. Here then was 

 an enormous loss of 825 per cent." Lastly, I extracted the grains 

 from the ears of mildewed specimens which I received from 

 Dumraon (attacked with P. rubigo), and found that they were not 



* I found later that 10 healthy grains weighed 60 of these, i.e., 500 per cent. 



