Evaluation of impact of a variety of organic fertilizers on the growth of guava and on the quality of soils in nursery

Abstract

Guava crop, Psidium guajava L., has a very high nutritional value, however, it is farming in Venezuela is neither extensive nor modern and it is limited to the area south of Lake Maracaibo. It was an important crop in the ’90s, but it suffered plagues and diseases that led to a decline in the production of guava and forced its farmers to locate its cultivation to the aforementioned area where it is currently grown. Another factor that negatively impacted the production of guava was the presence of nematodes, which passed from the nurseries to the fields. This study offers alternative agroecological management of nurseries of guava by evaluating the use of different organic fertilizers in order to determine their impact on the growth process of the plants as well as on the chemical and biological quality of the soils. Control group T1 (with no fertilizer) and 7 types of treatments were used: T2 manure tea (20%), T3 worm humus or liquid Vermicompost  (10%), T4 Azotobacter, T5 manure tea (20%) + Azotobacter, T6 Azotobacter + phosphorus solubilizer, T7 manure tea (20%) + worm humus or liquid Vermicompost (10%), T8 extract of plantain rachis (10%); 4 random repetitions in blocs were carried out. The best result obtained in plant growth was from treatment T7 (both on the aerial and root parts of the plant) followed by treatment T3 in the development of the root.  All the treatments applied maintained or improved the chemical quality of the substrate.