YlELD AND GROWTH PERFORMANCE OF FOUR AVOCADO (Persea Americana MilI.) 1CULTIVARS AT THE SOUTHERN SONORA REGION OF MEXICO

Abstract

The southern Sonora valleys in Mexico are grown to 377,125 ha under irrigated conditions, high percent of the surface is devoted to small grain crops. The NAFTA (North American Free Trade Agreement) signing offers a series of advantages and challenges to Mexican agriculture in order to share vegetable and fruit intemational markets. In this scenery Mexican avocado has played an important roll during the past couple of years because of the United States commercial opening. This research was conducted in Southem Sonora, Mexico (26. 41' and 290 NL, and 1090 12' and 109041: WL), from 1989 to 1997. Four cultivars ('Fuerte', 'Hass', 'San Miguel' and 'Ensenada') were planted on a sandy loam soil during march, 1989 in a array 10 x 10 m with five trees each cultivar. A completely random design was used with five replications a DMS P$0.05 test to separate treatrnents under study was used. Measured parameters were round-year stem diameter growth and height, number of fruits per tree, average weight of fruits and yield (t. ha"'). Analysis showed that stem diameter growth and height was !¡Iow during the first year in the field, but after that time, values increase gradually, with a maximum of 15 cm, and 150 cm in stem diameter and height respectively. The before-mentioned was as the result of an absence of strong sink and source relationship. A strong phenomenon of altemate bearing was observed in better performers such as 'Fuerte' and 'San Miguel', even when in a accumulative yield analysis, were high yielders. 'Hass' always yielded in an uprising manner throw the period of study average weight of fruits ranked between 107 to 242 9 being distributed from bigger to smaller size as follows: 'Hass', 'San Miguel', 'Fuerte' and 'Ensenada'.