Conversion of cotton production to certified organic management in the northern san joaquin valley: plant development, yield, Quality, and production costs

Abstract

Replicated mapping and harvest of sample plants in organic and conventional production systems in 1995 showed that yields did not significantly differ in the two systems, although yields were low in both production systems due to delayed planting under wet spring conditions. Boll retention was numerically higher in the organic production system; however this difference was only statistically significant at harvest at the lowest five positions. Boll retention at the negatively correlated with increased plant density in both production systems. Average internode first position was length and weekly height-to-node ratios, both indices of plant vigor, did not differ significantly between production systems. 1993 and 1994 quality factor measurements indicate that length, strength, micronaire, and leaf grade did not significantly differ between production systems. However, 36% of organic bales were classified as light spotted color grades in 1994, while conventional bales had few spotted grades. A preliminary comparison of 1994 operational costs of production showed that organic cotton had higher per acre production costs ($646/acre) than conventional cotton ($582/acre), including higher labor costs due to increased hand weeding requirements. Positive returns above operational costs for organic cotton could be projected for an average 1.6 bales/acre at a reported average price of $1.21/lb compared with positive returns above operational costs projected for conventional yields of 1.8 bales per acre at $0.80/lb in 1994. An average 44% premium was obtained for certified organic cotton.