Impact of diseases and pests on premature fruit drop in sweet orange orchards in São Paulo state citrus belt, Brazil.

Background: Despite technical improvements in the citrus chain and leadership in orange production achieved in the past decades, premature fruit drop remains a major component of crop loss in São Paulo state citrus belt, the largest sweet orange production area in the world. The present study aimed to determine, during five consecutive seasons, the impact of the diseases and pests on premature fruit drop in the orange belt.

Results: Fruit drop due to the main diseases and pests averaged approximately 11.

Tree age and cultivar-oriented use of mineral oil added to fungicide tank mixture for the control of citrus black spot in sweet orange orchards.

Background: Mineral oil added to fungicide spray mixtures has been a frequently used strategy to control citrus black spot (CBS) worldwide. Although mineral oil may increase the efficacy of control, its use represents around 15% of the costs of a CBS spray program. This study aimed to assess the performance of different proportions of mineral oil added to a fungicide tank mixture for CBS control in young (less than 10 years old) and old (more than 12 years old) sweet orange orchards of early ('Hamlin'), mid-season ('Pera') and late-maturing ('Valencia') cultivars in São Paulo state, Brazil.

Pathogen Dispersal and Glomerella Leaf Spot Progress Within Apple Canopy in Brazil.

Glomerella leaf spot (GLS) of apple is caused by three different species complexes. This study evaluated the dispersal of spores related to GLS temporal progress and defoliation. Spores were monitored by air and water runoff in different plant heights, and the temporal progress of GLS and defoliation were assessed.