A CHEMICAL GUIDE CHART FOR FRUITGROWERS.

New Zealand Journal of Agriculture, Volume XII, Issue 3, 20 March 1916, Page 194

A CHEMICAL GUIDE CHART FOR FRUITGROWERS.

DIAGRAM SHOWING THE EFFECT OF MIXING VARIOUS SPRAYINGCOMPOUNDS, BASED UPON A COMPARABILITY TABLE BY G. F. GRAY, CALIFORNIA, IN “ BETTER FRUIT,” AND INVESTIGATIONS BY W. C. MORRIS, HASTINGS, NEW ZEALAND. .

Any two compounds joined by thick lines ■aaaa are dangerous as combined ■.. . j . J . ‘ ■. . ' ■.> . sprays. Any.two compounds joined by thin lines are good mixtures proper- ■ t ties not interfered with. Any two compounds joined by dash lines are excellent mixtures—mix ' ' ■ ’ ing improves them. Any two compounds joined by two thin lines —= — are efficient and non-injuri- ■ < ousmixing does'not im- ' . . prove them. Any two compounds joined by wavy lines ~are inefficient and non-injuri-bus— no use mixed.

of two separate spraying-compounds are combined. While it is generally recognized in regard to fruit-tree spraying that the practical demonstration on the tree is the final test, and is altogether more reliable than that of the laboratory, there are certain chemical laws some knowledge of which would no doubt act as a sufficient warning against combining unsuitable ingredients.

In order to lessen the need of this knowledge of chemistry in respect to the ordinary ingredients and compounds used for spraying purposes, and to present the facts in a handy form, Mr. W. C. Morris, Agricultural Instructor to the Hawke’s Bay Education Board, has drawn up the chart here reproduced. Mr. Morris wishes it to be clearly understood that the chart is submitted merely as a guide, and is based on an article which appeared in the August, 1914, issue of “ Better Fruit,” a United States publication ; also that the decisions arrived at, although based on laboratory tests, are generally supported by practical experience. A careful study of this chart would no doubt prove of value to any one contemplating the combination of spraying-compounds the effect of which they have had no previous experience of. The spraying-compounds and terms used in connection with the chart refer only to those in common use for spraying purposes. “Emulsions” means any - class ,of oil emulsion, soaps, fish-oil, whale-oil, or other soaps used in spraying. ■ “ Acids ” and “ alkalies ” mean any ingredient showing an acid or alkaline litmus-paper test respectively. ' , The danger of cyanide both as a-poison and as a destroyer of foliage when improperly used in the fumigation of plants is generally, well known. It is not intended to convey the impression by the chart that cyanide can be safely used in conjunction with other ingredients for spraying purposes, but rather that the danger to plants is greater when fumigation is carried out immediately after spraying with Bordeaux mixture or Paris green, and that the contrary is the case in regard to tobacco-wash or lime-sulphur.— J. A. Campbell, Assistant Director, Horticulture Division. -

Californian - thistle Rust. Fields Inspector Webb, Masterton, writes : “ Californian-thistle rust has made rapid strides in this district, the settlers assisting by spreading it as suggested by the Biologist. I have sent several affected plants to non-affected areas. AH have taken this season, and have done an immense amount of good in the direction of controlling the weed.”