Herb farm and root disease. Successful management of plant diseases include environmental controls similar to that of the pest management plan. Chemical means are determined based on the type of plant disease present in the herb. Herb plants can be started from seed or purchased as a seedling. Common herbs grown from seed are basil, flat and curly leaved parsley, chives, dill, sage, thyme, rosemary, cilantro. Herbs can also be grown via vegetative means, rooting cuttings, division of the plant, bulbs, or tissue culture. The advantage of growing via a vegetative process gives you a plant that is exactly identical to the
Leaf valve Leaf valve A leaf valve is a one-way valve (check valve) consisting of a diagonal obstruction with an opening covered by a hinged flap. Patents exist in the United States which specify the mechanical use of leaf valves to control various types of fluids. United States Patent 4930535 is a folding leaf valve which is described as a valve that, "folds upon itself to provide positive sealing of a pressurized chamber under a variety of pressure conditions. In particular, the valve stem folds to effectively close the lumen and provide a positive seal even at low differential pressure." United States