effect of sulfur pesticide on the quality of fresh pistachios in cold storage

The efficiency of sulfur in controlling pistachio pests, especially psylla, has been documented in the available literature, but it is essential for pesticides not to affect the quality of the product. in this study, movento (0.5 l/1000 l), confidor (0.4 l/1000 l) and refinery micronized (r) and mineral (m) sulfur (30 and 60 kg/1000 l in water) were sprayed twice on pistachio trees of the cultivar ‘ahmadaghaei’ (in mid-may and 50 days thereafter). pistachios were harvested in late september and were stored at 4 °c for 25 and 50 days to evaluate the effects of pesticides on the quality of hulls and kernels. the taste, aroma, appearance, respiration rate, firmness of hull and kernel, a* (red-green), b* (blue-yellow) and chroma of hull and kernel declined over time, while l* (lightness) and the hue angle of the hull and kernel increased. ethylene production remained stable over time. chemical pesticides stimulated hull firmness. refined micronized sulfur at both concentrations caused higher l* and hue angle, but lower a*, b* and chroma in the hull and kernel (i.e. lighter and yellower in color). all sulfur treatments reduced the firmness of the hull and kernel, while also increasing the respiration rate. r30 preserved the taste and aroma after 50 days. r30 and m30 showed higher ethylene production. the r30 treatment had some positive effects on preserving the taste and aroma of pistachios overtime. thus, it may be recommended as a reliable treatment, although the ability of sulfur in pest control could be offset by the side effects of sulfur on product quality.