Seedlings of several conifer species can be difficult to transplant, with the problem often related to poor root regeneration. The objective of this study was to determine if corkbark fir (Abies lasiocarpa arizonica) seedlings or pinyon pine (Pinus edulis) seedlings would produce more root growth when grown in a Missouri gravel bed growing system compared to field soil. The 3–0 fir seedlings and 4–0 pine seedlings were planted in a gravel bed in mid-April. The gravel bed was 3 m × 3.7 m and was filled with a mixture of 60% pea gravel (1 cm minus), 30% Turface®, and 10% silica sand (by volume). A field bed 3 m × 3.7 m in size was also prepared. Fir seedlings were harvested in September and October, but pinyon pine seedlings were harvested only in October due to their poor transplant survival. Plant heights, stem diameters, and root volumes, as well as root and shoot dry weights, were determined at harvest. Of all the measured growth parameters for both species, only root dry weights and root volumes were significantly different. In particular, fir seedlings grown in the gravel bed produced at least 30% more root dry weight and 74% more root volume than those planted in field soil whether plants were harvested in September or October. Likewise, pine seedlings grown in gravel produced at least 37% more root dry weight and 86% more root volume than those grown in soil. In addition, only 10.6% of the pine seedlings planted in soil survived transplanting, but 23.3% of those grown in the gravel bed survived. This study demonstrated that corkbark fir and pinyon pine seedlings grown in a gravel bed produced larger root systems than those planted into field soil, and the gravel bed also improved pinyon pine seedling survival after transplanting.
Robert R. Tripepi and Mary W. George
Sahar Dabirian and Carol A. Miles
Rootstock regrowth can prevent effective healing of grafted vegetable seedlings and outcompete the scion for light, space, and nutrients later in production. Rootstock regrowth is especially problematic for watermelon (Citrullus lanatus) because the crop is most commonly grafted using methods where meristematic tissue remains on the rootstock. The objective of this study was to test whether sucrose solutions [0% (water control), 1%, 2%, and 3%] applied as a drench to rootstock seedlings before grafting would increase the survival of watermelon grafted using the splice method where both rootstock cotyledons were removed to eliminate meristem tissue and rootstock regrowth. Starch accumulation in rootstock seedlings was the highest for plants that received 3% sucrose solution (71%), followed by plants that received 2% sucrose solution (52%), 1% sucrose solution (29%), and water (6%) (P < 0.0001). Survival (%) of splice-grafted watermelon seedlings 21 days after grafting was the greatest for plants that received 2% and 3% sucrose solution (89% and 82%, respectively), followed by plants that received 1% sucrose solution (78%), and was the lowest for plants that received water (58%) (P < 0.0001). There was a significant interaction due to repeat for both starch accumulation and grafted transplant survival; however, environmental conditions were similar for both repeats: the daily average temperature was 23 °C, the relative humidity (RH) was 64% to 67%, and the daily average light intensity was 224–243 µmol·m−2·s−1. Furthermore, while the vapor pressure deficit from 1:00 to 6:00 pm was 2.49 kPa for repeat 1 and 1.42 kPa for repeat 2, plant survival was greater in repeat 1 than repeat 2. These results indicate that drench applications of sucrose solution to rootstock seedlings before grafting can increase grafting success when both cotyledons are removed from the rootstock before grafting, but further research is needed to optimize the environmental conditions for the survival of grafted plants.
Marc van Iersel
Mechanical conditioning can be used to control the height of vegetable and ornamental transplants. Previous research indicated that brushing plants increases cuticular water loss from detached leaves, which may be an indication of decreased drought resistance. This might decrease post-transplant survival of the plants. The objectives of this study were to determine the effect of brushing on growth and gas exchange by tomato (Lycopersicon esculentum Mill.) and quantify whole-plant water use during a slow dry-down period. Tomato plants were grown from seed in a greenhouse during Fall 1995. The brushing treatment started 11 days after seeding and consisted of 40 strokes, twice each day. After 39 days of treatment, brushing reduced height 32%, leaf area 34%, and shoot dry mass 29% compared to control plants. Brushing did not affect leaf gas exchange. Brushed plants had a higher stem water flux than control plants during the first 3 days of a 6-day dry-down period. Stem water flux was lower than that of control plants later in the cycle, presumably because brushed plants used more of the available water during the first 3 days. On the third day of the dry-down period, leaf conductance of brushed plants was 35% higher than that of control plants, resulting in a 10% higher transpiration rate per unit leaf area. Because brushed plants had less leaf area than controls, differences in whole-plant water use were small. Time to wilting was similar for the brushed and unbrushed plants (6 days after withholding water). It seems unlikely that brushing would have a major effect on drought tolerance of plants.
William B. Thompson, Jonathan R. Schultheis, Sushila Chaudhari, David W. Monks, Katherine M. Jennings, and Garry L. Grabow
by hand because laborers on the mechanical transplanter periodically fail to place good quality plants in the mechanical transplanter fingers. The planting depth can also affect transplant survival and overall yields because of the number of nodes
products, applied 1 day before grafting to both scion and rootstock seedlings, increased the survival of newly grafted watermelon transplants. Survival was 30% greater with the stomata-closing antitranspirant than the control (water) for ‘TriX Palomar
cucumber production. Guan et al. (p. 74) evaluated the effect of grafting using squash rootstocks on plant growth and yield of seedless cucumbers grown in high tunnels during spring seasons in Indiana. The grafted plants had higher transplant survival
Areej A. Alosaimi, Robert R. Tripepi, and Stephen L. Love
micropropagation along with high percentages of rooting and transplant survival resulting in high throughput propagation of a selected accession. Having a rapid method to multiply plant numbers will allow a superior selection of a native plant to be introduced more
measure root growth easily and inexpensively As the landscape horticulture industry continues to grow, techniques to improve survival of difficult-to-transplant ornamentals are needed. Current methods of studying root growth, a key factor in transplant
Sudeep Vyapari, S.M. Scheiber, and E.L. Thralls
.K. 1993 Effect of copper-treated containers on transplant survival and regrowth of four tree species J. Environ. Hort. 11 196 199 Watson, G.W. Himelick, E.B. 1997 Principles and practice of planting trees and shrubs Intl. Soc. Arboriculture Savoy, IL Wood
Frederic B. Ouedraogo, B. Wade Brorsen, Jon T. Biermacher, and Charles T. Rohla
289 SAS 2017 SAS/STAT 14.1 User’s guide. 3 Oct. 2018. < http://support.sas.com/documentation/cdl/en/statug/68162/HTML/default/viewer.htm#statug_nlmixed_syntax.htm > Struve, D.K. 1993 Effect of copper-treated containers on transplant survival and