Growth periodicity is generally conceived as a set pattern of growth incited by internal factors and influenced by environmental conditions ( Morrow, 1950 ). The inherent alternation between periods of abundant root and shoot growth and little or
Lisa E. Richardson-Calfee, J. Roger Harris and Jody K. Fanelli
Haijun Zhu and Eric T. Stafne
, 1970 ). It is also the most common characteristic observed by growers, who associate it with tree vigor and nutrition. There can be a large variation in shoot growth on the same tree or different trees. Old trees tend to produce short shoots while young
Stephen S. Miller
tree is a moderately vigorous to vigorous cultivar. The growth suppressant prohexadione–calcium (PCa) (Apogee; BASF Corp., Agricultural Products Group, Research Triangle Park, NC) has demonstrated excellent shoot growth control in a number of apple
Jonathan P. Lynch
to root growth and maintenance, which diverts resources from shoot growth and reproduction. In perennial plants, reproduction may be foregone entirely in a stressful season. Increased risk . Expression of a trait may generate risks of abiotic
Dilma Daniela Silva, Michael E. Kane and Richard C. Beeson Jr.
-to-shoot ratio is also modified by natural growth patterns. Many woody species, such as Ligustrum japonicum Thunb., exhibit an episodic growth habit, fluctuating between periods of rapid shoot growth and slow root growth and periods with the inverse pattern
Todd C. Einhorn, Mateus S. Pasa and Janet Turner
for apple. In 2010 and 2011, shoot length was recorded weekly at both sites on ten 1-year-old shoots selected at a similar canopy height and position and tagged at the time of the first application. Shoot length was measured until shoot growth ceased
Thomas W. Zimmerman and Ralph Scorza
This study examined stage I peach shoot growth under various photoperiods in combination with different vessel closures and compared the influence of BA and Thidiazuron (TDZ) on peach shoot growth during stage II. The basal salts were as described by Almehdi and Parfitt (1986) with 1.0 μM BA, 0.02 μM IBA, 2% sucrose, 0.1% gelrite and 0.4% agar. Shoot growth of peach clone B612615, as determined by leaf number after one month, was similar in vessels capped with Kim-Kaps, Kaputs or PM caps. Plastic foam Identi-Plugs resulted in desiccation of the medium and stressed shoots with reduced growth. A 4 h light/2 h dark photoperiod four times a day provided better growth during stage I than a 16 h light/ 8 h dark photoperiod. For stage II, established shoots of Suncrest, Georgia Bell and Evergreen were grown on MS medium supplemented with 0.02 μM IBA in combination with 1.0 or 10 μM BA or 0.1, 1.0 or 10 μM TDZ. TDZ produced excessive callus resulting in minimal shoot proliferation. Shoot proliferation from axillary buds was greatest with 10 μM BA.
Guglielmo Costa, Anna Maria Bregoli, Emidio Sabatini, Bomben Cristina and Vizzotto Giannina
The efficacy of Prohexadione-Ca on vegetative and reproductive parameters was tested for 3 years on three apple cultivars (Golden Delicious, Braeburn, and Fuji) at concentrations ranging from 125 up to 350 ppm. The Prohexadione-ca was applied after shoots reached 5 cm length, for 1 month. In all cases, Prohexadione-Ca reduced shoot growth, showed the tendency to increase fruit size and to enhance return bloom. In addition, it increased leaf coloration and higher chlorophyll content, and it induced higher photosynthetic efficiency than the control. The relationships among shoot reduction, chlorophyll content and photosynthetic efficiency are discussed.
Jeff S. Kuehny and Mary C. Halbrooks
Episodic growth is a term used to define alternate episodes of root and shoot growth. Fresh weight gain of Ligustrum japonicum roots and shoots was continuous through each episode of shoot elongation. Root:shoot ratio, however varied over time and oscillated with each episode of shoot elongation. During shoot elongation the percent fresh weight (of whole plant weight) allocated to the shoot decreased while the percent allocated to roots increased. During cessation of shoot elongation the percent fresh weight allocated to the shoot increased; while percent allocated to roots decreased. Formation of lateral roots was synchronous with shoot elongation.
Sven E. Svenson
The objective of this study was to determine if shading and DCPTA application interactively influence seedling emergence and shoot growth of Hypoestes phyllostachya Bak. seedlings. Hypoestes `Carmine Red' seeds were soaked for 6 h in distilled water, and then soaked 6 h in solutions containing' 10 mg DCPTA/liter (30 mM) and 0.1% Tween-80, 0.1% Tween-80, or distilled water. Date of seedling emergence was recorded after sowing (0.5 cm) in 9-cm (460 ml) pots filled with 440 ml of a 5 pine bark: 4 Florida sedge peat: 1 sand medium. Forty pots from each of the three seed-soak treatments were grown under 30%, 63%, or 84% shading, provided by saran-type shadecloth, using natural photoperiods (completely randomized design). Shoot heights and dry weights were recorded 75 days after sowing. Neither shading nor DCPTA influenced total seedling emergence or seedling emergence rate (time to 50% emergence). Under 30% shading, seedlings from DCPTA-treated seeds were taller and had more shoot dry weight than seedlings from surfactant- or water-treated-seeds; however, DCPTA did not influence seedling height or shoot weight under 63% or 84% shading.