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Exact scheduling is necessary to suppress Diploctiapinea, a fungus which becomes destructively endemic in conifers, especially Austrian pine. It blights and browns-off twig tips, which must be pruned in cold weather and carried away together with all old cones, on which diplodia's dormant fruiting bodies show like black pepper. The first eruption of new spores will occur on that warm, humid spring day (but which one?) when the pine's young "candles" burst their husks. Right then you must hit diplodia with a copper or mercury spray, and hit it again at short intervals (but how short?) twice or oftener (but how much of-tener?). If the weather continues mild and damp, about ten days is the interval and thrice more, the frequency. But once it has taken hold, don't expect to get rid of diplodia permanently. You will be lucky if you keep it under control. This is why Austrian pine, and to a less degree the Scotch and red, are less popular than formerly in what has become diplodia territory. These examples of ticklish timing are extreme. They are cited early in our account of anti-parasite strategy to emphasize that, in this warfare as in any other, timetables are critical. The seasons govern the foes' behavior and therefore our own. RIGS Successful chemical warfare in trees consists in getting there at the right time with the right material. For not to exceed $25 the home owner can acquire hardware that will deter any invasion up to fifteen feet (add a stepladder for five feet more). To protect his natural pump-fountains he needs only a mechanical pump-fountain through which his arm can supply about twenty pounds of pressure to a column of liquid nozzled into a rain or mist. |
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