Abstract

The effect of several strategies - alone and integrated - on the control of the Phytophthora sp. fungae, which causes radical rotting of papaya fruits, was evaluated under nursery conditions. The experiment took place between August 1994 and March 1995 at the University of Costa Rica's Estación Experimental Fabio Baudrit, located in Alajuela, Costa Rica. The treatments applied were: sun heat for 30 days; organic fertilizer made from hen droppings; etridiazole fungicide; and the following combinations: sun heat + etridiazole + organic fertilizer; etridiazole + organic fertilizer; sun heat + etridiazole; sun heat + etridiazole + organic fertilizer, and finally, an inoculated control treatment. Soil rows were made, and then they were innoculated with the pathogenic agent, and finally the aforementioned treatments were applied. The treated soils were bagged separately. The Solo Sunrise Hawaiian variety was planted in bags. The percentage of gerrnination, stem diameter at soillevel, plant height, radical system fresh weight, and severity of radical rotting were evaluated three months later. In addition, the effect of the treatments on beneficent soil microorganism populations (actinomyces, protozoa, bacteria, and fungi) was evaluated, as well as those of pathogenic populations. Organic fertilizer increased plant strength. All treatments affected germination; the innoculated control had the greatest germination percentage. Treatments containing organic fertilizer affected germination most.