''Ripening'' Tobacco with the Ethylene-Releasing Agent 2-Chloroethylphosphonic Acid

Abstract

Treatment of flue-cured tobacco with the ethylene releasing agent 2-chloroethylphosphonic acid (CEPA) caused mature leaves to lose their green colour and turn yellow. The treated leaves appeared to go through a partial "yellowing'' or "colouring" phase prior to harvest. Treated leaves at harvest contained greater amounts of reducing sugars and lower levels of starch, relative to comparable untreated leaves. At the end of the curing process, comparisons between treated and untreated leaf showed that only small differences existed in total nitrogen, total alkaloids, starch, and reducing sugars. Statistically, protein of leaf treated with CEPA was significantly lower as compared to untreated leaf. For all yellowing times, dollar values per hundred weight of cured leaf from treated plants were higher than from untreated plants, but the average weight per leaf from treated plants was lower. During the curing process, leaf treated with CEPA can probably be subjected to shorter periods of yellowing or colouring than untreated leaf. If further work with "ripening'' chemicals such as CEPA show that they can be used to hasten yellowing or ripen tobacco successfully, as well as to reduce the time required for curing the crop, economic advantages are likely to accrue. It is to be hoped that such chemicals may help reduce the labour and investment required for crop production, and at the same time improve crop quality

The Role of Ethylene in the Senescence of Oat Leaves

“…18), it was natural to look for a function of this hormone in senescence, and indeed it was reported early to increase leaf senescence (6,12,27). Our own experiments (14) ' Supported in part by grant (33), and causes increases of respiration and of ATP, along with the loss of Chl-the typical senescence syndrome (31). Another is the well-known role of ethylene in the maturing of fruit, a process which, in three respects-namely loss of Chl, hydrolysis of polymers, and climacteric rise of respiration-obviously has much in common with the senescence of leaves (34).…”

Natural and Synthetic Growth Regulators and Their Use in Horticultural and Agronomic Crops

“…Ethephon increases the number of leaves that may be harvested at one time and decreases the curing time for the leaf (49). This treatment is especially useful in the cooler tobacco-growing regions where the uppermost leaves, which are the last to be harvested, may be damaged by frost.…”

Some Effects of 2‐Chloroethyl‐phosphonic Acid (CEPA) on Burley Tobacco (Nicotiana tabacum L.) Cured Detached from the Stalk1

“…An ethylene-releasing agent, 2-chloroethyl-phosphonic acid (CEPA), has been found to "ripen" plant leaves. Steffens, Alphin, and Ford (5) reported that mature flue-cured tobacco leaves appeared to ripen when treated with CEPA before harvest. CEPA-treated flue-cured leaf was found by Miles et al (3) to be lower than untreated leaf in yield, total nitrogen, and total alkaloids.…”