Small Flowering Trees Deserving Greater Use

Small flowering trees are gaining in popularity for several reasons. First, small 3 to 6 m (10 to 20 ft) trees fit modern landscapes where yards are small. Secondly, there is a growing and somewhat justified fear of urban trees that get huge with time. In an age of hurricanes, tornadoes, wild weather and predictions by climatologists of more of the same, it is only reasonable to embrace a little fear of large trees. Part of climate change ― is violence. Crushed homes, vehicles, and power lines are becoming nightly fare on our national news. Small flowering trees suddenly look better. Thirdly, there is an ever-expanding list of new varieties entering the market with attributes of tree form, leaf shape and color, and flower size and color. Finally, five to ten gallon container-grown plants mesh well with the displays at the mass markets, independent nurseries, and landscape companies

Ethylene production by the potato tuber

December 1971.Covers not scanned.Includes bibliographical references.Russet Burbank tubers were stored at 32°F and 45°F and continuously ventilated with atmospheres of 2% O2, air, 80% O2, 4% CO2, 12% CO2, and intermittently ventilated with air. Ethylene production by the tubers was traced throughout a seven month storage period. Tubers stored in atmospheres of 2% O2, air, 4% CO2, and intermittent air at 32°F and 45°F evolved ethylene at a rate no greater than 0.008 ul kg-1 hr-1 throughout the storage period. In all cases where sprouting occurred, the rate of ethylene production increased. Tubers stored in 80% O2 and 12% CO2 succumbed to physiological breakdown and produced ethylene at rates much greater than the rates for tubers stored in the non-toxic atmospheres (2% O2, air, 4% CO2, and intermittent air). The peak rate of ethylene production observed was 0. 300 ul kg-1 hr-1 for tubers stored in 80% O2 at 45°F. In general, the higher temperature produced the higher rates of ethylene production. The only exception to this rule were those tubers stored in 12% CO2. Tubers inoculated with Alternaria solani and Fusarium roseum var. sambudnum were investigated for the ethylene-producing ability. Uninoculated tubers and tubers inoculated with Alternaria solani evolved ethylene at approximately the same rate. Tubers inoculated with Fusarium roseum, however, demonstrated greatly stimulated ethylene production, often as high as 0.100 ul kg-1 hr-1. Cultures of Fusarium roseum grown on PDA failed to produce ethylene

Can We Improve the Salinity Tolerance of Genotypes of Taxidium by Using Varietal and Hybrid Crosses?

Taxodium distichum (L.) Rich. var. distichum [baldcypress (BC)], Taxodium distichum var. mexicanum Gordon [Montezuma cypress (MC)], and a Taxodium hybrid (‘Nanjing Beauty’: BC · MC cross, T302) were evaluated for salt tolerance in 2006 at Nacogdoches, TX. Plants were irrigated weekly with four levels of salinity [0, 1, 3.5, and 6 ppt (0, 17, 60, and 102 mol[1]m–3)] for 13 weeks and then 0, 2, 7, and 12 ppt (0, 34, 120, and 204 mol[1]m–3) for another 12 weeks. Salinity treatments did not have a significant effect on growth rate; however, there were significant differences in growth rate among the three genotypes. Genotype T302 produced the greatest wet weight, whereas MC had stronger apical dominance and exhibited the greatest increase in height over the course of study. As expected, sodium (Na) concentration in Taxodium leaves increased as sea salt concentrations increased but did not tilt Na/potassium (K) ratios to stressful disproportions. Of the three genotypes, BC exhibited the highest leaf content of Na, calcium (Ca), sulfur (S), and iron (Fe); MC had the lowest leaf content of Na, Ca, S, and Fe; and T302 was intermediate. The benefits of using a hybrid cross (T302) that maintains greater biomass than BC or MC across a range of salinities must be weighed against the potential additional pruning and training necessary for cutting-grown clones relative to BC and MC propagated from seed and flood tolerance relative to BC. Still, combining the best characteristics of different varieties of T. distichum should facilitate the production of favorable genotypes tolerant to a number of soil physical and chemical property fluctuations for arboricultural operations