Elevated Carbon Dioxide Alters Hydrocarbon Emissions and Flavor in Onion

Abstract

Bulb onion (Allium cepa), non-bulbing Japanese bunching onion (A. fistulosum), common chives (A. schoenoprasum) and garlic chives (A. tuberosum) have markedly different harvest indices. With the onset of bulbing, leaf production ceases, photosynthates are reallocated to the bulb, lowering production of new shoots and crop canopy. Successive harvests from the same planting allow for a cumulative harvest index. In testing the influence of growing plants under different CO 2 conditions, a set of volatile methyl-ketones have been identified from onion that are emitted at higher levels when plants are grown at elevated CO 2 compared to controls grown at ambient CO 2 levels. Sensory panel taste testing has indicated differences in flavor for some cultivars when comparisons were made between plants grown at ambient and elevated CO 2 conditions. In future studies we will examine if thiosulfinates generated from the enzymatic conversion of alk(en)yl cysteine sulphoxides contribute to flavor differences detected between ambient and elevated CO 2 grown plants.

Identifying the Growth Limiting Physiochemical Parameter for Chives Grown in Biologically Treated Graywater

“…The absence of fecal coliforms and total coliforms in the effluent were confirmed by the weekly analysis of effluent samples of the TTU-WRS conducted over a period of several months, resulting in limited concern of human pathogens in the graywater. Chives were selected for these experiments due to extensive work conducted at TTU and they are a candidate crop that may be included in future space missions due to their ability to regenerate leaves after harvesting (Paré et al 2004). Additionally, the green leafy part of the chives does not come into contact with the graywater growth medium, limiting the concern of growing edible crops in wastewater.…”