This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
What has been called "Smudging" is an exceedingly inelegant name for the process of preventing damage to the fruit crop through frost in early spring by means of a smother of smoke, or by maintaining the temperature above the danger point with fires placed about among the fruit trees, or by a combination of both.
The idea has come from the exceedingly wideawake fruit growers of America, whence most of the processes now on the market have also been imported. From the valleys of California and the irrigated plateaux of Colorado come wonderful accounts of whole populations turning out at midnight, on electric summons from the mayors, and all, without distinction of rank or calling, joining in "fighting the frost"; returning, after sunrise, begrimed and fatigued, but victorious over the foe that otherwise would have swept the orchards clean of any promise of fruit.
The prospect is an attractive one. The danger of losing all through a spring frost has been a sort of nightmare to fruit growers as far back as the days of Shakespeare, who puts into the mouth of the fallen Wolsey the words:
"This is the state of man: to-day he puts forth The tender leaves of hope; to-morrow blossoms, . . . The third day comes a frost, a killing frost; . . . And then he falls. . . . And when he falls, he falls like Lucifer, Never to hope again."
On an average it is estimated that in two years out of five the fruit crop in England is a failure, and nearly always the immediate agent of the destruction seems to be frost.
If, therefore, it is argued, the fruit crop could be effectively protected against frost, instead of the uncertainty which at present is so unpleasant a factor in fruit growing in this country, there would be the reasonable prospect of regular crops, and commercial arrangements such as at present are impossible could be made for dealing with them. Another result would be, it is claimed, that fruit growers, assured of continuous crops, would thin systematically and a better quality of fruit would be put on the market, instead of being tempted, as now, to leave on the trees all the fruit that comes when there is a crop, from fear of losing any of it.
For two years various devices have been advertised in this country. Several demonstrations have been held, and some growers have purchased experimental quantities, but up to now not one of the processes can advance the recommendation which, it appears, can be advanced at the other side of the Atlantic, viz. that it has saved a crop. Until this can be said the adoption of any of them will naturally be slow. Those who have already tried smudging are unable to say that the crop was appreciably heavier where it was applied than where it was not. It is an ill task to decry a new invention - and every succeeding generation has provided its own confirmation of the stupidity of the mental attitude that says " it can't be done" - but it may be permitted to point out that it is at least unwise to promise as good results here as are reported to have been obtained in America. The difference in climate and atmosphere between a comparatively small island like ours and a vast continent like America is considerable and must be taken into account. Many modifications may be necessary before devices which may be successful in America become suited to our requirements.
Again, it is held by competent observers that the fruit crop is made or marred in the autumn, and that though the frost in spring appears to work the destruction, it is really only the sword of the Assyrian executing the doom pronounced in the autumn.
The wet, almost sunless autumn of 1909, for instance, prevented the proper ripening of the wood, so that the blossom in spring was debilitated and lacked stamina sufficient to withstand the buffeting of what Thomson called the "ethereal mildness". Notwithstanding, there have been occasions when a healthy promising prospect has been marred by one severe frost, and if a workable weapon of defence can be placed in the grower's hands it cannot fail to be of great advantage.
The introduction of methods of smudging is too recent to admit of the cost of working being clearly ascertained. Apart from the cost of installing plant, which will be from £7, 10s. to £10 per acre, the cost of keeping the fires in action for a single night is about 25s. for 1 ac.
[W. G. L.]