Effect of Carbon Dioxide on Propagation of Softwood, Conifer and Herbaceous Cuttings

Abstract

cuttings in an atmosph"t" "r.r"fffT"T$ Tar The chrysanthemum cuttings were treated with 3-indol-butyric acid at 1,000 ppm, and the softwood and evergreen cuttings with 3,000 PPT'-Po1e1-tilla and chrysanthemum cuttings were lifted after 2 weeks and weigela, thuja and iuniper cuttings after 4-8 weeks.The number of roots per cutting was counted and their,length was measured. Potentilla and chrysanthemum cuttings were weighed before inserting and again after lifting.The data from the growth rooms and the mist frames were analyzed statistically by the r test oisignificance. Growth Rooms RESULTSIn the growth rooms, the atmosphere enriched with CO, significantly-increased the rooting percentage and produced more roots Per cutting (Table 1)

Relations between carbohydrate, water status and adventitious root formation in leafy pea cuttings rooted under various levels of atmospheric CO2 and relative humidity

“…In contrast to data from the present investigation, it has been reported that CO2 enrichment during rooting not only increased root system size, but also increased the number of roots formed per cutting in nearly all species and cultivars tested (Molnar and Cumming 1968). More recent work indicates that the effect of CO2 enrichment on rooting is highly variable (Davis andPotter 1983, French andLin 1984) and dependent upon taxa even within species (Lin and Molnar 1981).…”

“…Adventitious root formation by some leafy cuttings has been altered by treatments that presumably altered the supply of current photosynthate or carbohydrate levels (Davis and Potter 1981, Eliasson 1978, Howard and Sykes 1966, Molnar and Cumming 1968, Veierskov et al, 1982b, where current photosynthate is defined as products of photosynthetic activity after excision from the stock plant. Because within a few day after excision photosynthetic rates of leafy cuttings are low compared Received 8 May, 1989 Physiol.…”

“…77, 1989 to those of intact plants (Davis and Potter 1981, Eliasson and Brunes 1980, Okoro and Grace 1976, increasing photosynthesis of cuttings might promote rooting, CO, enrichment during rooting should enhance photosynthetic rates of leafy cuttings. Several investigators have reported that COj enrichment during propagation increased rooting percentage and number of roots per cutting from some, but not all, taxa tested (Bhattacharya et al, 1985, Davis and Potter 1983, French and Lin 1984, Lin and Molnar 1981, Molnar and Cumming 1968 The physiological basis for enhanced rooting in atmospheres enriched with CO2 has not been investigated thoroughly. High CO2 not only increases photosynthesis (Zelitch 1971) and tissue carbohydrate content, but it also causes partial stomatal closure (Raschke 1975), thus reducing transpiration and possibly raising water potential {•\\)^) or turgor pressure (\|jp).…”

The Physiology of Rooting Populus Cuttings

“…In addition, an increase in rooting success has often been reported when cuttings are given favourable conditions for photosynthesis, achieved for instance by enriching the atmospheric carbon dioxide concentration ' Permanent address: Federal Department of Forest Research, Ibadan, Nigeria. (Molnar and Cumming 1968). However, environmental factors which might be expected to result in a high rate of photosynthesis and high levels of carbohydrate in the cuttings, sometimes inhibit rooting; for example, Hansen and Eriksen (1974) showed that in Pistim, root formation was inhibited when the stock plants were kept at high irradiance over the range 7-60 W m~^, and suggested that supraoptimal carbohydrate contents were responsible for the inhibition.…”

The Involvement of Current Photosynthesis in Rooting of Hardwood Cuttings of ^|^lsquo;Delaware^|^rsquo; Vines

“…Most investigators agree that photosynthesis in leafy cuttings plays an important role in root formation (1,2,3,7,8). It is also generally accepted that the rooting of hardwood cuttings depends upon stored carbohydrates (5)…”