Higher Levels of ABA and IAA Are Found in Green than in White Asparagus Spears

abscisic acid (ABA) We conducted a field ex-periment to determine if ABA and IAA con- centrations differ in asparagus (Asparagus officinalis L.) spears grown in light or dark-ness.Five-year-old ‘Jersey Giant’ asparagus plants were grown uncovered to produce green spears. White spears were produced by growing plants under opaque black rowcov- ers (< 0.2 µmol·m -2 ·s -1 of photosyntheti-cally active radiation at midday) as described by Makus and Gonzalez (1991), or by cut-ting spears that grew under 20 cm of sawdust mulch placed on top of the soil. The design was a randomized complete block with the three treatments replicated four times. Replicate row lengths were 7.3 m. All treatments were cut at the same 2- to 3-day frequency at least 10 days before the sampling data. Two to 3 days elapsed from the time of spear emergence to harvest height in all treatments. Fifteen spears from each treatment and were Apr. to 5 cm from the lyophilized 72 a a 40-mesh (0.36 ) while purging with The the Lab-oratory, for analysis of and