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Brian Christensen, Sridevy Sriskandarajah and Renate Müller

very valuable in ornamental plants. The aim of the present study was to further characterize plants obtained in an earlier study ( Christensen et al., 2008 ). The focus of the investigation was to elucidate alteration in biomass distribution between

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Mario Pérez-Grajales, Víctor A. González-Hernández, Ma. Carmen Mendoza-Castillo, Cecilia Peña-Valdivia, Aureliano Peña-Lomelí and Jaime Sahagún-Castellanos

Six manzano hot chile pepper landraces (Capsicum pubescens R & P) were evaluated to identify genotypes which might contribute toward obtaining superior hybrids by providing the following characteristics: low height, short internodes, rapid biomass accumulation, high harvest index, high fruit quality, and high photosynthetic rate. The landraces studied were `Chiapas', `Huatusco I', `Huatusco II', `Perú', `Puebla', and `Zongolica'. Plants were grown in a shaded glasshouse for 9 months, with drip irrigation. Growth, biomass distribution, fruit quality and yield were determined. All varieties exhibited advantageous characteristics, i.e., large fruit (60 mL) with thick pericarp (4.2 mm) in `Puebla'; short internodes (10 cm) in `Zongolica' and `Huatusco II'; high harvest index (0.24), high yield (18 to 19 t·ha−1) and high relative growth rates (0.12 g·g−1·d−1) in `Perú' and `Puebla'; and high dry mass accumulation (450 g/plant) in `Chiapas'. The highest photosynthesis rate in manzano hot pepper was 7.7 μmol of CO2/m2/s at 500 μmol photons/m2/s, in `Zongolica' and `Puebla'.

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Xiuming Hao and Athanasios P. Papadopoulos

Tomato (Lycopersicon esculentum Mill) `Trust' was grown on rockwool with nutrient solutions containing two levels of calcium (150 and 300 mg·L-1) in factorial combination with three levels of magnesium (20, 50, and 80 mg·L-1) in Winters 1997 and 1998, to investigate the effects of calcium and magnesium on growth, biomass partitioning, and fruit production. Plants grown at 20 mg·L-1 Mg started to show Mg deficiency symptoms (leaf chlorosis) at 8 weeks after planting. The chlorophyll content of middle and bottom leaves increased with increasing Mg concentration in the nutrient solution. At 300 mg·L-1 Ca, total fruit yield and fruit dry matter increased linearly with increasing Mg concentration; marketable fruit yield and total plant biomass showed similar response but to a lower degree. At 150 mg·L-1 Ca, total plant biomass, fruit dry matter and yield peaked at 50 mg·L-1 Mg. The biomass allocation to fruit increased while allocation to leaves decreased with increasing Mg concentration. The Mg effects on total and marketable fruit yield were mainly due to its influence on fruit yield in the late growth stage. Incidence of blossom-end rot (BER) at 150 mg·L-1 Ca increased linearly with increasing Mg concentration while it was not affected by Mg concentration at 300 mg·L-1 Ca. For a winter greenhouse tomato crop, the appropriate Ca and Mg concentrations for tomato production appear to be at 300 and 80 mg·L-1, respectively.

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Julián Miralles, Raquel Valdes, Juan J. Martínez-Sánchez and Sebastián Bañón

The appropriate management of crop conditions can reduce the salt damage suffered by ornamental species and produce high-quality plants even when saline irrigation water is used. The aim of this study was to determine whether the pot-in-pot (PIP) cultivation system can improve the saline irrigation tolerance of Euonymus japonicus compared with aboveground potting (AGP) in terms of growth and development, aesthetic quality, ion accumulation, and leaf potentials. A 5-month experiment started on 6 Mar., and the interaction between the cultivation system (PIP or AGP) and water quality (fresh water and saline water, with 1.76 and 9.04 dS·m−1, respectively) was assessed. The substrate used was a mixture of white peat, coconut fiber, and perlite (40/40/20, v/v/v). A soil moisture sensor-controlled system was used to irrigate all the treatments when the AGP treatment irrigated with fresh water reached a volume water content (θ) of 0.33–0.35 m3·m−3. An interaction effect reduced the salinity effects in PIP and saline irrigation (PIP-s) compared with AGP and saline irrigation (AGP-s) in terms of damaged leaf area, plant dry weight (DW), and the compactness index. The PIP-s plants showed a survival rate of 93% compared with 57% in AGP-s. The substrate temperatures were milder in PIP regardless of the irrigation water, and the pore water electrical conductivity (EC) was 36% lower in PIP-s than in AGP-s. PIP reduced the Cl accumulated in leaves but did not influence Na+, Ca2+, Mg2+, or the K+/Na+ ratio. The lower amount of Cl accumulated increased leaf water potential (Ψo) in PIP. Saline irrigation produced a general accumulation of Cl and Na+ in leaves and decreased Ca2+, Mg2+, the K+/Na+ ratio, Ψo, the shoot to root ratio, and height. In general, PIP reduced the salinity damage to Euonymus japonicus, the main effect being the lower Cl ion uptake, which improved its aesthetic value (less damage and greater compactness and growth).

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Amy L. Neigebauer, Garald L. Horst, Donald H. Steinegger and Greg L. Davis

Significant research has been conducted on wildflower sod, but the reasoning behind the production system methods is not clear. The purpose of this research was to determine the influence of mowing height on the subsequent leaf growth and root biomass distribution in a wildflower sod production system. Rudbeckia hirta was grown in sand in polyvinyl chloride (PVC) tubes in simulating field conditions. Plants were either not mowed (control) or hand-clipped to 5.1, 7.6, or 10.2 cm to simulate mowing. After the initial mowing, plants were mowed at ≈7-day intervals. Total root depth, number of root axes in the top 2.5 cm, root: shoot ratio, total root dry weight, and root dry weight at depths of 0.0-2.5, 2.5-21.7, 21.7-40.8, and 40.8-60.0 cm were measured at the end of the study. Comparing the total root dry weight of all segments indicates that mowing significantly reduces root biomass. As mowing height increased, the depth of longest root increased linearly. Plants not mowed or plants mowed to 10.2 cm produced significantly more root axes in the top 2.5 cm of sand than did mowing heights of 5.1 or 7.6 cm. Root dry weight in the top 2.5 cm was considerably greater in nonmowed plants. Increased root axes in sod with higher mowing heights indicated a greater root density, which may also increase wildflower sod stability.

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Ute Albrecht, Mireia Bordas, Beth Lamb, Bo Meyering and Kim D. Bowman

cuttings, and TC, during the first weeks of growth in the greenhouse. The influence of rootstock and propagation type on root structure and biomass distribution is discussed, as well as the possible implications of propagation method for field performance

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Martin P.N. Gent

area, biomass distribution, and fruit production. This acclimation should be observable in terms of changes over time in the radiation, water, and nutrient use efficiencies. The present work examines water and nutrient uptake of greenhouse tomato crops

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Dennis R. Decoteau

( Decoteau et al., 1988 ; Fortnum et al., 2000 ). These growth measurements often do not account for biomass distribution differences that may be occurring among plant parts at individual nodes that contribute to overall shape and structure of the crop

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Taryn L. Bauerle, William L. Bauerle, Marc Goebel and David M. Barnard

distribution is examined as a measure of root biomass distribution. This is the first study to examine the variability in substrate moisture sensor readings that arises from root distribution and function among containerized tree species. Our data show a clear

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Jennifer M. Bousselot, James E. Klett and Ronda D. Koski

. 2007 A new method for non-destructive measurement of biomass, growth rates, vertical biomass distribution and dry matter content based on digital image analysis Ann. Bot. (Lond.) 99 777 783 Vidmar, J. Kelley, K