THE GARDENERS' CHRONICLE. 24: 276) [Oct 8, 1898)
THE ORANGE-FUNGUS ON ROSES.
D. T. Fish.

"Wild Rose's" experience of the sudden attacks of this insidious pest is all too common. Its origin and life-history are still more or less obscure, and hence probably its check or cure is still beyond the skill of most growers. Prevention, however, would be better than either. The late Thomas Rivers was one of the first to discover that this pest was most virulent on the rougher-leaved Roses, such as Moss, Provence, and spiny hybrid perpetuals. His advice, too, to intercrop Roses with annuals and other crops, aimed rather at growing out red-rust through an increase of vigour in the constitution of the Roses, than through any curative virtue in the mere change of crop. In this connection, it should however be borne in mind that our great champion Rose-grower, Mr. Benjamin Cant of Colchester, has long adopted the plan of taking a white or corn crop in alternation to his Roses.

Mr. Rivers' radical trenching and manuring were powerful auxiliaries in keeping the land full of suitable food throughout the season. Sudden checks arising from gluts or scarcity of food, and floods or famines of water, are the most potent causes or sure forerunners of red-rust on Roses. Excessive and sudden changes of temperature, from extremes of cold to heat, often come immediately before, if they do not produce and foster, the growth of orange-fungus. A loose surface among Roses throughout the growing season is the nearest antidote yet found for the prevention and cure of red or orange-fungus. The intervention of a white crop, the constant use of the hoe on the surface, to keep the roots cool and moist, sweetly and regularly fed, are useful helps.

Like "Wild Rose," I have long known that the red-rust seldom or never attacks Teas, Hybrid Teas, Noisettes, Bourbons, Chinese, or Banksian, or smooth shining-leaved Roses. Even such Perpetuals as Boule de Neige, the Verdiers, and other more or less smooth and shining-leaved hybrid perpetuals escape the orange-fungus. Can it be that this pest cannot lay hold of or remain long enough upon the leaves to effect its reproduction? Suppose we try to starve out this fungus by offering it nothing to feed upon but smooth semi-shining varnished-leaved Roses.

We need not lose so very many of our very best Roses by adopting such a method. New and smoother-leaved varieties will come at the cultivator's and hybridiser's bidding; as readily as new colours, forms, odours, among our Rose blooms. Little progress has been made for many years in attempts to kill the orange-fungus without injury to the Rose trees. For example, Paris Green and London Purple may be used strong enough to kill the fungus, but hardly without scorching, disfiguring or killing the foliage and flowers.

A small brush dipped in pure alcohol, methylated spirits, or a strong decoction in solution of smelling-salts deftly and lightly thrust against the fungus, will cripple or kill it, and if cleverly managed, will inflict but little injury on leaf or branch. But should wider experience prove all smooth-leaved Roses fungus-proof, complete deliverance from this pest may be said to be already within sight of cultivators. For every day Teas, hybrid Teas, and climbers are increasing, while the hybrid perpetuals and other rough-leaved rust-inviting Roses are decreasing.