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Growth Control of Purple Firespike

A large, showy tropical shrub growing to about 2 m tall with an upright habit and attractive lavender flower spikes, purple firespike has potential as a new flowering potted plant. Rezazadeh and Harkess (p. 71) studied the efficacy of five plant growth regulators, along with pinching and number of cuttings, to control plant growth. Aesthetically pleasing potted plants were achieved by planting one cutting per 6-inch pot and pinching twice (2 and 6 weeks after potting), or by using a drench application of 8 ppm uniconazole, 30 ppm paclobutrazol, or 15 ppm flurprimidol.

Tree Canopy/Vegetation Rate and Stress-related Illness

One-third of Americans reportedly are living with extreme stress, with 75% to 90% of visits to primary care physicians for stress-related problems. Tarar et al. (p. 76) examined whether stress-related illness rates in regions of Texas were linked to vegetation rates and tree canopy cover. They found no significant positive or negative relationship between stress-related illness data when compared to percent canopy and vegetation index for any of the 25 metropolitan statistical areas of Texas.

1-MCP Improves Avocados Held Under Commercial Conditions

Berry et al. (p. 85) evaluated the effect of aqueous 1-methylcyclopropene (1-MCP) on ripening and quality of Guatemalan-West Indian avocado hybrids ‘Monroe’ and ‘Booth 8’. Respiration rate, ethylene production, softening, and change in epidermal hue angle were delayed and/or suppressed in both varieties exposed to 1-MCP. Avocados treated with 1-MCP maintained better appearance during ripening under simulated commercial shipping temperatures than did untreated fruit. However, there was no effect of 1-MCP on ripening rate. Harvest maturity had a greater effect on the onset of ripening than treatment with 1-MCP.

Value and Age of Residential Homes Affects Lawn Watering

Bremer et al. (p. 90) surveyed residential homeowners about their lawn-irrigation behaviors based on their home’s value, age, and lot size. Owners of more expensive and newer homes were more likely to water frequently and routinely, feel it important to have green lawns, and sweep grass clippings and lawn-care products off impervious surfaces. A small percentage of homeowners swept clippings or lawn-care products into storm drains, especially owners of less expensive, older homes. Educational efforts should be focused on homeowners with more expensive, newer homes for water conservation and on homeowners with less expensive, older homes for water quality protection.

Honey Bee Brood Pheromone Improves Yield of Hybrid Carrot Seed

Over the years, various tactics have been employed to enhance honey bee pollination in crops that are unattractive to honey bees, without much success. Honey bee brood pheromone, a synthetic blend of honey bee larval pheromone, has been shown to stimulate honey bee foraging in controlled field studies, but its potential to increase crop yield has not been tested. In a 3-year field study Sagili et al. (p. 98) found that honey bee brood pheromone has the potential to increase both honey bee foraging and yield in hybrid carrot seed crops.

Plant Growth Regulators Suppress Growth of Pineapple Lily

Pineapple lily can have excessive foliage and inflorescence growth making the use of plant growth regulators (PGRs) desirable to improve plant quality. Carlson et al. (p. 105) drenched bulbs of ‘Leia’ pineapple lily with flurprimidol, uniconazole, and paclobutrazol at five different concentrations and found that as concentration increased, days to anthesis increased and foliage and inflorescence height decreased for each PGR. Acceptable concentrations were paclobutrazol at 0.5 to 2.0 mg/pot, uniconazole at 0.25 to 2.0 mg/pot, and flurprimidol at 0.5 to 1.0 mg/pot, based on percentage of marketable plants and height suppression without excessively increasing the days to anthesis.

A Low-cost Sensor-based Irrigation System

Ferrarezi et al. (p. 110) designed and built an automated irrigation system using four capacitance soil moisture sensors, a low-cost open-source microcontroller, and solenoid valves. The technology effectively monitored and controlled volumetric water content over a range of thresholds (0.2, 0.3, 0.4, and 0.5 m3·m−3) to trigger the irrigation. The equipment is inexpensive and easily accessible. The system required little maintenance over the course of a 41-day trial with ‘Panama Red’ hibiscus in a peat-perlite substrate. The low cost of this irrigation controller ($667) makes it useful in many horticultural settings, including both research and commercial production.

Performance and Biodegradation of Biobased Plant Containers

Industry standard petroleum-based plant containers are made from nonrenewable materials and rarely are recycled. Many currently available biocontainers are not durable enough for plant production. Kratsch et al. (p. 119) evaluated 28 prototype containers made from bioplastics and biocomposites for their performance during plant production and biodegradation in the dissimilar soils and climates of Iowa and Nevada. Containers made from polylactic acid or polyhydroxyalkanoate composites performed well. Adding biobased fibers to form composite materials improved biodegradation and had little negative effect on container performance. The highest rated containers functioned similarly to petroleum-based containers, yet were biodegradable in soils.

Decision Tool to Evaluate Economics of Grafted Tomatoes

Rysin and Louws (p. 132) used data for conventional field tomato production to demonstrate how growers can assess the economic viability of using grafted transplants based on their specific circumstances. Yield improvements in the grafted system with resistant rootstocks were sufficient to offset higher transplant and harvesting costs, and resulted in higher net revenues ($8374/acre in the grafted system vs. $7126/acre in the non-grafted system). Estimated marketable yield required in the grafted system to breakeven as compared with the non-grafted system was 73,880 lb/acre, or 19,980 lb/acre more.

High Tunnel Variety Trial of Tomatoes in the Northeastern U.S.

High tunnel tomatoes have become an important component of many diversified New England farms. Warren et al. (p. 139) evaluated 15 indeterminate tomato varieties grown in an unheated high tunnel for yield and other characteristics. Variety performance varied widely. Several varieties performed well, for example: Geronimo consistently had high marketable yields in terms of weight; Arbason or Massada produced large numbers of fruit; and Rebelski, Massada, and Geronimo were resistant to two common diseases. Radar plots were used as a tool to graphically represent many of the performance characteristics and to make results easily comparable among varieties.

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