Crop Booster

Help please! I have just bought an old gardening book called the "Vegetable Plotter" and it keeps mentioning a product called "Crop Booster" Any idea what this is?

Is it an American book Nige? There appears to be a registered TM product called Crop Booster which appears to be American.. 

Lorna, It's an very early book by Dr.D.G Hessayon who went on to write the "Expert" books.

It could still be the stuff. Hesssayon spent time in America, did he not?

Yes I think he did!
 I have googled the stuff and to be honest I was not impressed with what came up! Hence I asked for clarification on the forum to what it was in good old plain English.

Pretty useless if I remember rightly.

Is that the sort of plain English that would help? 

All comments are appriciated