lettuce
...rganic matter from previous crops, and control of pests and diseases. This operation is followed by deep ripping the soil profile 2 to 3 feet, breaking up any underlying soil compaction for improved root and water penetration. Then laser leveling is done using a landplane to improve irrigation efficiency of the soil. Laser leveling typically is performed by a contract leveling company every two to four years. Following leveling of the field, chicken manure is spread on the soil. Chicken manure is custom applied a week or more prior to the lettuce bed formation. The manure is broadcasted, and then incorporated by discing the soil twice to break up any remaining clods and to smooth and firm the soil. After discing, the soil is ready for bed preparation and it is then listed into lettuce beds of 40 inches width Planting + Spacing :. To achieve proper spacing of plants, thinning of lettuce seedlings is usually necessary. Thin plants of leaf lettuce four to six inches or more between plants depending on plant size. Butterhead and romaine should be thinned six to ten inches between plants. Finally, crisphead transplants should be spaced 10 to 12 inches apart in the row. Watering: Lettuce has a shallow root system and requires frequent watering to stimulate rapid leaf development. Too much water on heavy soils may lead to burning of the leaves and root diseases. Don’t wet the foliage any more than necessary when watering. Weed Control: Weeds common in this area include the various winter grasses and broad leaf weeds. Many growers and consultants advise against planting lettuce without using herbicide. In this study, an application of kerb herbicide is broadcasted at 3 pounds per acre. At the time of thinning the lettuce crop, hand weeding is also a common practice. Pest and Diseases and Control Measures: the most serious pests of lettuce, are aphids, cutworms, leaf miners, slugs, and beet leafhoppers. All can be controlled with insecticides or baits. The disease most frequently found on lettuce in home gardens is white mold (Sclerotinia sclerotiorum). Symptoms include wilting and dropping of leaves with a white, cottony growth around the base of the plant at and below the soil line. White mold is a problem in gardens that are kept too wet and particularly in gardens that are flood-irrigated. Do not plant lettuce in a poor water drainage area. Lettuce plantings on raised beds help prevent wh...