Reversed Greenhouse Temperatures Alter Carbohydrate Status in Lilium longiflorum Thunb. `Nellie White'

Abstract

<jats:p>Commercial greenhouse operators are increasingly using “negative DIF” temperature regimes to control crop height. A negative DIF exists when greenhouse night temperature is greater than the day temperature. Large negative differences in day and night temperatures strongly suppress stem elongation in many crops. We have explored the effects of negative DIF temperature regimes on leaf, flower, and stem carbohydrate levels in <jats:italic>Lilium longiflorum</jats:italic> Thunb. `Nellie White'. During two growing seasons, `Nellie White' plants were grown under positive or negative DIF regimes (±5 or 8C) under prevailing daylengths, with temperatures adjusted so that daily temperature averages were equal between regimes. Plants were harvested ≈10 days after visible bud stage and at anthesis. Carbohydrates in stems, leaves, and flowers were analyzed by high-performance liquid chromatography. Compared to plants grown under positive DIF, negative DIF plants showed significantly reduced stem length and leaf and stem dry weights. Negative DIF regimes reduced leaf and stem total soluble carbohydrate (TSC) content by 39% to 46% at visible bud and anthesis, while flower TSC content was reduced by 10% to 13%.</jats:p>

Growth Regulators Delay Foliar Chlorosis of Easter Lily Leaves

“…This, is turn, suggests that the postproduction development of foliar chlorosis in Easter lily leaves may be associated with the carbohydrate status of the leaves. Other researchers have proposed a similar theory for the cause of foliar chlorosis based on the various cultural practices followed in the greenhouse (Jiao et al, 1986, Miller, 1992Miller et al, 1993). Application of triazole and close spacing of plants during greenhouse production results in lower leaf carbohydrates as well as a higher percentage of leaf yellowing.…”

Ancymidol Drenches, Reversed Greenhouse Temperatures, Postgreenhouse Cold Storage, and Hormone Sprays Affect Postharvest Leaf Chlorosis in Easter Lily

“…'Nellie White' Easter lily plants were grown under natural photoperiod and irradiance in a greenhouse at Clemson University following standard cultural practices (Miller, 1992). Three separate experiments were conducted during Spring 1993, 1994. In 1993and 1994 precooled at 4 °C for 6 weeks were planted into 1.4-L plastic containers using a commercial potting mix (Fafard No.…”

“…GENERAL CULTURAL PRACTICES AND POSTHARVEST EVALUATION. 'Nellie White' Easter lily plants were grown in glass greenhouses under negative (13.5/21.5 °C) or positive (24.0/15.5 °C) DIF at Purdue University under conditions as described by Miller et al (1993). At the puffy bud stage, plants were sleeved, boxed, and shipped by truck to Clemson University.…”

“…(Moe et al, 1992). Miller et al (1993) found that negative DIF regimes decreased carbohydrate levels in Easter lilies, but little work on negative DIF effects on postharvest characteristics in Easter lilies has been reported.…”

“…Postproduction leaf chlorosis can be induced by both preharvest factors such as high doses of growth retardants and early termination of fertilization (Prince and Cunningham, 1989), and postproduction factors such as cold storage before marketing, and shipping stress (Prince et al, 1987). However, the interactions of preharvest factors with (Miller et al, 1993), or treated with ancymidol (Bailey and Miller, 1989;Jiao et al, 1986). It may be hypothesized that depletion of carbohydrate and N reserves is related to the degree of postharvest leaf chlorosis in Easter lilies.…”