Tuberous root production in "mauka" cultivar (Mirabilis expansa [Ruiz and Pavón] Standley) with application of organic fertilizer and chemical fertilization in Puno - Peru Juan Gregorio Zapana Pari, Marina Mamani Sucasaca, Fortunato Escobar-Mamani, Juan Carlos Zapana Landaeta 275-284 2017-09-27