Saturday, November 23, 2013

Lime Sulfur Spray for Apple Trees

Lime Sulfur Spray for Apple Trees

Anyone who has grown apple trees knows that they involve a fair bit of maintenance. In fact, most apple trees need to be sprayed with certain pesticides on a regular schedule in order to protect the growing apples (and the tree) from invaders. Lime sulfur spray is one such spray that apple tree owners can use to combat a number of pests. The spray is also environmentally friendly because it is devoid of harsh chemicals. Does this Spark an idea?

Basics

    Lime sulfur spray can refer to a number of sprays that contain various forms of sulfur. Calcium sulphide and calcium polysulphide are two common chemical formulations used in lime sulfur sprays. Sulfur itself can be toxic to some plant species so manufacturers add lime or calcium to soften the impact of the sulfur. The spray is intended as a fungicide, meaning it has a direct effect on fungi and fungal spores. Essentially, when the lime sulfur spray encounters the fungi, it inhibits the germination of spores and hinders its growth. The product can also be used against mites although how it works against them is unclear.

Application

    Lime sulfur spray is sold either as a ready-to-use mixture (RTU) or as a concentrate. The concentrated forms need to be mixed with water at a certain ratio that depends on the strength of the concentrate. Once the spray is ready, it is applied to the tree, mainly on the leaf. As a rule, the spray should be applied to the apple tree until it lightly drips off the edges of the leaves. When and how frequently the apple tree needs to be sprayed with lime sulfur depends on the individual pest management schedule of the owner.

Problems Treated

    The lime sulfur formulation is used to treat a number of apple tree problems. As noted, the spray is intended as a fungicide thus its main uses are in the control of apple scab, powdery mildew, black knot and black spot. The product can also be used to treat against mites as well but large infestations may require a miticide to properly handle the problem.

Downfalls

    One downfall of lime sulfur spray is that it is limited in its effectiveness because it only treats fungi that are already present. Thus, although the product can be said to have use as a preventative measure, what is really happening is that any spores that are already on the tree will refuse to develop because of the spraying. Another downfall with lime sulfur is that it cannot be mixed with dormant oil, a type of substance used commonly to treat the insect problems apple trees experience. Therefore, a gardener who sprays with lime sulfur would have to wait at least four days to apply dormant oil without harming the tree.

Cost

    Lime sulfur is fairly inexpensive and averages about ten dollars a quart, as of 2010. Factor in the number of times during the season the product needs to be used and how many trees need to be sprayed to get a better idea of what the total seasonal cost will be.