Base-line Growth Studies of ‘First Lady’ Marigold in Controlled Environments1

Abstract ‘First Lady’ marigold (Tagetes erecta L.) was grown 3 times in each of 5 different controlled environment facilities to establish baseline growth rates for this species. Plants were grown under a standardized set of environmental conditions established with a common set of standardized instruments. Data on plants grown only once in two additional laboratories are reported for comparative purposes. The variation in growth within each laboratory was greater than the average variation among laboratories for cotyledon length and width, plant weight measurements, and 3rd leaf length but not for leaf width. The base-line growth data, based on the described procedures, can be used to compare marigold growth in other controlled environments and to provide a check on the operational characteristics of research facilities.