This week's "Green Tip," dealing with drip irrigation, is provided by the Horticulture Club: The way water is mostly lost is through evaporation. To eliminate this, drip irrigation should be used whenever possible. Installation of the drip-tubes is fast and inexpensive. It not only applies water directly where it is needed, but it waters deeply and thoroughly. Compared to spray irrigation, drip irrigation uses far less water and will encourage plant roots to grow down in search for the deep water. (Contacts for the "Green Tip of the Week" feature are Gail B. Landers , group leader at the Children's Learning Center and a member of the Energy Conservation Subcommittee, and Carl J. Bower Jr. , horticulture instructor.)