Peso fresco y calidad de nopalito (Opuntia ficus-indica L.) fertilizado con composta de estiércol de vaca:

La produccion de nopal verdura en Milpa Alta, D.F., Mexico, se ha basado por mas de 40 anos en la utilizacion de altas dosis de estiercol fresco de vaca (hasta 600 t.ha-1) y podria ser fuente de gases de efecto invernadero como metano y oxido nitroso; se necesitan alternativas de nutricion amigables con el ambiente. Para comparar diferentes fuentes de fertilizacion en el rendimiento de planta y en la calidad y vida de anaquel de cladodios, plantas de tres anos de edad fueron tratadas con composta, lixiviado de composta aplicado al suelo o asperjado al tallo, estiercol fresco de vaca y fertilizante sintetico; plantas tratadas con agua aplicada al suelo o asperjada al tallo fueron tratamientos testigo. Respecto al rendimiento, no hubo diferencias significativas entre tratamientos. Los cladodios de plantas tratadas con composta y estiercol fresco mostraron un pH menor (4.7) que aquellos de plantas tratadas con agua aplicada al suelo (5.1; p ≤ 0.007). Cladodios de plantas tratadas con fertilizantes sinteticos mostraron mayor resistencia al corte (6.9 Nw) que aquellos de plantas tratadas con estiercol (5.2 Nw), lixiviado de composta foliar (5.1 Nw) y agua aplicada al suelo (5.1 Nw; p ≤ 0.002). Cladodios de plantas tratadas con fertilizante sintetico y lixiviado de composta foliar tardaron mas dias en mostrar oscurecimiento en anaquel (4.6 y 4.4 dias, respectivamente) que aquellos producidos con agua aplicada al suelo (1.2 dias; p ≤ 0.001). Se concluye que la composta de estiercol podria ser un sustituto apropiado del estiercol fresco de vaca para fertilizar el cultivo de nopal verdura. Abstract Cactus crop as a tender leaf at Milpa Alta, D.F., Mexico, has depended for more than 40 years in the use of high doses of fresh cow manure (600 t.ha-1) and this could be a source for greenhouse gases such as methane and nitrous oxide; friendly nutrition alternatives are needed to the environment. To compare different sources of fertilizing on cactus plant yield, cladode quality and cladode shelf-life, three-year-old cactus plants were treated with compost, compost lixiviate applied to the soil or as a foliar spray, fresh cow manure and synthetic fertilizer; plants treated with water applied to the soil or as a foliar spray served as checks. Regarding to the plant yield, there was no statistical difference among treatments. Cladodes of plants treated with compost and fresh manure showed a lower pH (4.7) than those of plants treated with water applied to the soil (5.1; p ≤ 0.007). Cladodes from plants treated with synthetic fertilizer showed higher resistance to cutting (6.9 Nw) than those from plants treated with manure (5.2 Nw), foliar sprayed with compost lixiviate (5.1 Nw) and water applied to the soil (5.1 Nw; p ≤ 0.002). Cladodes of plants treated with synthetic fertilizer and foliar sprayed with compost lixiviate took more days to show darkening on shelf (4.6 and 4.4 days, respectively) than cladodes from plants treated with water applied to the soil (1.2 days; p≤0.001). It is concluded that compost manure could be a suitable substitute for fresh cow manure in fertilizing cactus tender leaf crops. Keywords: compost lixiviate, organic production, enzymatic browning, shelf-life quality.