Use of cassava industry wastewater as a potassiun source on lettuce crop (Lactuca saliva L.) in greenhouse conditions

Use of cassava industry wastewater as a potassiun source on lettuce crop (Lactuca saliva L.) in greenhouse conditions. This work was conducted in 2006 at Embrapa/UEP/Rio Largo, located at the Delza Gitai Campus - Agrarian Science Center Academic Unity - UFAL, aiming to evaluate the use of cassava industry wastewater as a potassium source on lettuce crop in different doses. The research was conducted in a plastic greenhouse, in randomized complete blocks with six treatments and six repetitions, being the treatments: 0, 100, 200, 300, 400 and 500 mL of cassava industry wastewater per 5 L vase. The lettuce cultivar Regina SF 3500 was used, and the harvest was performed 33 days after transplantation. Leaf area, fresh leaf mass, dry leaf mass, number of leaves, fresh stem mass and fresh root mass were evaluated. Cassava industry wastewater can be used as a source of potassium for lettuce depending on the applied dose.