Yield losses caused by Colletotrichum gloeosporioides in three species of Stylosanthes

Abstract

Yield losses from the fungal disease anthracnose, caused by Colletotrichum gloeospovioides, were estimated for 3 species of Stylosanthes grown in northern Queensland. Naturally infected control plots of S. scabra cv. Fitzroy, S. hamata cv. Verano and S. guianensis cv. Graham were compared with plots protected by 3 benomyl spray treatments designed to restrict anthracnose development to 0, 25 and 50% of the level sustained in the unsprayed control plots. Following initial infection in early February 1984, disease incidence and severity in Fitzroy and Verano reached a maximum during early March. This rapid build up of disease was associated with a period of sustained wet weather. Graham only became infected much later in the season as the plants matured, and sustained severe anthracnose lesions on both leaves and stems even though weather conditions appeared unsuitable for an epidemic. Yield losses were severe in all 3 cultivars. Average dry matter yields of the unsprayed controls were only 21.6, 66.7, and 53.5% respectively of the yields of the disease free plots for Fitzroy, Verano and Graham. Corresponding seed yields were 15.6, 48.9 and 42.5% respectively. Highly significant negative correlations were found between dry matter and seed yields of the 3 species and the incidence and severity of anthracnose disease.

Machine learning techniques in disease forecasting: a case study on rice blast prediction

“…Davis et al . did not find any obvious relationship between disease severity and weather, and infection could not be associated with any specific sequence of weather events [15]. Using multiple linear regression (REG) analysis, Chakraborty and Billard showed that REG model was not equally effective in predicting infection events in the 2 years of their field study in Australia [16].…”

Genetic relationships among isolates of Colletotrichum gloeosporioides from Stylosanthes spp. in Africa and Australia using RAPD and ribosomal DNA markers

“…Colletotrichum gloeosporioides is regarded as the major pathogen on various Stylosanthes species cultivated as pasture legumes, causing important crop losses in its centre of origin, South America (Grof et al ., 1979), as well as in the tropical and subtropical areas to which it has been introduced: Africa (Clatworthy, 1975; Maraite, 1993) and Australia (O'Brien & Pont, 1977; Davis et al ., 1987). In Africa, severe anthracnose caused by C. gloeosporioides has also been reported on various fruits (Jeffries et al ., 1990).…”

Latent colonization byColletotrichumspp.: Epidemiological considerations and implications for mycoherbicides

“…It has been suggested that latent infection by C. gloeosporioides occurs in S. guianensis and S. capitata until reproductive maturity and plant senescence, when disease symptoms become more apparent (35). In field evaluations of Stylosanthes spp., increasing anthracnose severity has been observed with advancing plant maturity (20,21,29); although definitive evidence for latent infection is lacking (21,44), an indirect association (41), possibly with large diurnal temperature fluctuations, may be a factor (35). The current results, using only one cultivar of S. guianensis var.…”