Timing of Pistacia chinensis Bunge. Rooting Using Morphological Markers Associated with Calendar Date and Degree Days

Abstract

<jats:p>The objective of this study was to determine the most advantageous time to collect cuttings of Chinese pistache, a commonly recommended ornamental shade tree that is difficult to propagate by cuttings. In 1993, calendar date and degree days (daily mean temperature -7.2C) were used to estimate an appropriate cutting time. The greatest percentage of rooted cuttings occurred in male cuttings harvested on 13 May 1993 (397 degree days) and treated with 17,500 mg·liter<jats:sup>-1</jats:sup> IBA or in male cuttings harvested on 20 May 1993 (482 degree days) and treated with either 8750 or 17,500 mg·liter<jats:sup>-1</jats:sup> IBA. In 1994, cutting time was associated with calendar days, degree days, and morphology. The most rooted cuttings (44%) were from green softwood cuttings taken on 9 May 1994, which was 380 degree days from orange budbreak using a threshold temperature of 7.2C. Orange budbreak was characterized by separation of the outer bud scales such that the orange, pubescent inner bud scales were visible. Cuttings taken on 9 May 1994 and treated with 8750 mg·liter<jats:sup>-1</jats:sup> IBA produced the most primary and secondary roots and the longest primary roots per cutting. Male Chinese pistache cuttings should be collected from green softwood or red semi-softwood stems when about 380 to 573 degree days have accumulated after orange budbreak. Chemical names used: indolebutyric acid (IBA).</jats:p>

Early rooting of dormant hardwood cuttings ofPopulus: analysis of quantitative genetics and genotype × environment interactions

“…We used soil temperature instead of air temperature because belowground temperature had a greater influence on rooting. The plant sciences use GDD to predict growth, harvest dates, insect outbreaks, and other biological phenomena (Eisensmith et al 1980;Dunn et al 1996;Zalesny et al 2004). The GDD value is the sum of the average temperature in a 24-h period minus a base temperature; the base temperature equals a threshold that supports adequate plant growth over a specified period.…”

Etiolation Improves Rooting of Bigtooth Maple Cuttings

“…However, within the time frame of this research, there was no clear affect of GDD on rooting. GDD have been used to predict cutting dates for chinese pistache (Pistacia chinensis) (Dunn et al, 1996). They were also explored by Alsup et al (2003) in relation to successful rooting of sugar maple, and while there was greater rooting early in the year and they were able to recommend taking cuttings at 350 to 520 GDD (threshold temperature 45°F), they did not report a significant impact on root number or length.…”

Genetic and environmental effects on rooting ability of dormant unrooted hybrid poplar cuttings

“…Since these temperatures were recorded throughout the study, I felt it much more meaningful to use them in the analysis in lieu of planting date. Growing degree days (GDD) have been used in the plant sciences to predict growth, harvest dates, insect outbreaks, and other biological phenomena (Dunn et al 1996, Eisensmith et al 1980, Newman et al 1968). GDD are defined as the average temperature in a 24-hour period minus a base temperature, where the base temperature equals a threshold that supports adequate plant growth.…”