California Agriculture (Jul 1999)
Preliminary studies show yield and quality potential of organic cotton
Abstract
For three years (1993 to 1995), we monitored organically and conventionally managed cotton fields in Madera County, and measured pest and beneficial arthropod populations, plant growth and development parameters, nutrient status, plant density, yields and lint quality. Square (flower bud) retention was similar in the two systems, although western tarnished plant bugs (Lygus hesperus or lygus bugs) were significantly more abundant on several dates in the organic fields. On most dates, populations of the predatory insects Geocoris spp. were significantly higher in the organic than in the conventional fields. Lint yields were not significantly different for the two production systems in any of the three years, but were lower than county averages in all years. In 1994, lint quality in the two treatments differed in that color grades were more variable in the organic cotton bales. Late spring rains also affected planting success in each year and the shortened seasons in 1994 and 1995 generally kept yields in both treatments at or below two bales per acre.