Traffic Tolerance of Experimental Bermudagrasses

Haselbauer et al. (p. 94) evaluated the tolerance of five experimental hybrid bermudagrasses and three commercially available bermudagrass varieties (Tifway, TifGrand, and TifSport) to overseeding, mowing regimes, and simulated athletic traffic. Experimental bermudagrasses Tift 11 and 2004-76 and ‘TifGrand’ yielded turfgrass cover values greater than or equal to ‘Tifway’ on all rating dates throughout the study. Findings suggest that ‘TifGrand’, 2004-76, and Tift 11 may be suitable for use on athletic fields.

In-row Watermelon Pollenizers Not Competitive at Four Planting Ratios

The competitive impact of in-row watermelon pollenizers grown equidistant from neighboring triploid plants was examined by Adkins et al. (p. 70), using four ratios of pollenizers : triploids (1:1, 1:2, 1:3, and 1:4). No significant difference in yield based on the weight or number of fruit per triploid plant resulted from the varied pollenizer ratios. Pollenizers grown in-row at an equidistant spacing from the neighboring triploid plants had no competitive impact on the yield of the triploid watermelon crop.

Method for Sex Determination of Asparagus Seedlings

Male asparagus plants usually produce greater spear yields than females, while female plants produce thicker spears. Geographic isolation of males and females can produce the desired quality of spears and prevent weed problems caused by seed production. Ii et al. (p. 77) developed a screening method to expedite sex determination in asparagus seedlings. Using a single step DNA extraction, excised roots of 19-day-old seedlings provided sufficient DNA for polymerase chain reaction (PCR) analysis without retarding seedling growth. Multiplex PCR using a ribosomal RNA gene marker made the screening method reliable by preventing false-negatives.

Growth Regulators Applied to Tomato Seedlings under Cold Stress

Jiang et al. (p. 137) report that applications of abscisic acid (ABA), putrescine (Put), or 2,4-epibrassinolide (EBR) at appropriate concentrations effectively reduced the decline in net photosynthetic rate and chlorophyll content in tomato leaves caused by suboptimal temperature stress in both ‘Zhongshu6’ (chilling sensitive) and ‘SANTIAM’ (chilling tolerant). The same treatments promoted increases in organic osmolyte (proline and soluble sugar) content and root 2,3,5-triphenyltetrazolium chloride-reducing activity in ‘Zhongshu6’. These effects were less on ‘SANTIAM’ than on ‘Zhongshu6’. For both varieties, 1 mM ABA, 0.1 mM Put, and 0.02 μM EBR were the best treatment concentrations.

Controlled-release Fertilizer Research Methods Used in Vegetable Production

Controlled-release fertilizers (CRFs) are coated with resin, polymer, sulfur, or a hybrid of polymer and sulfur. Carson and Ozores-Hampton (p. 20) present a comprehensive description of research methods used to measure nutrient release from CRFs. The methods are divided into three categories: laboratory, greenhouse and/or growth chamber, and field methods. Nitrogen (N) analysis methods used in conjunction with CRF incubation methods are discussed. Research objectives determine the most appropriate CRF methods and N analysis. Field release methods should be considered to be the most reliable indicators of CRF-N performance until laboratory methods are found that reliably predict expected field response.

Novel Approach to Grafting Tomatoes Can Generate Additional Income

More than 40 million grafted tomato plants are produced annually in North America. Generally, the lower parts of the plants (stumps) are discarded after using the tops (scions) for grafting. Hanna (p. 72) reports that cutting the scions above the cotyledon leaves stimulates sprout initiation on the stumps. Plants generated from the sprouts produced similar yields to plants generated from seeds for 16 weeks of the 19-week harvest season. The sprout plants were 3 weeks younger than the seedling plants, which resulted in an early reduction of yield. Marketing hybrid plants produced from the sprouts can generate significant income for the grafting industry.

Weed Management in Organic Vidalia® Onion

Johnson et al. (p. 64) conducted experiments to develop weed management systems for organic Vidalia® onion production. Treatments were all possible combinations of summer solarization, cultivation with a tine weeder, and clove oil herbicide. Summer solarization did not control cool-season weeds. Cultivating transplanted onion with a tine weeder effectively managed cutleaf eveningprimrose and improved yields in 2 of 3 years. The 1 year of marginal weed control with the tine weeder was due to persistently wet soils. Clove oil provided marginal weed control. No treatment, particularly cultivation with a tine weeder, increased diseases of stored onion.

Nitrogen Nutrition of Stock Plants for Herbaceous Perennial Cuttings

In commercial propagation of perennials, the yield of high-quality rooted cuttings is the goal. The number of cuttings harvestable from each stock plant is important as is rooting percentage and root growth. Two experiments on dianthus, gaura, perovskia, and salvia (Twardowski et al., p. 89) found little benefit from the higher nitrogen (N) rates, but the 0 and 50 ppm N treatments produced the lowest number of potential cuttings across all species. Overall performance of stock plants and cuttings for these species was generally optimized with 100 and 150 ppm N and produced the highest number of high-quality rooted cuttings.

Minnesota Vegetable Growers Survey Examines Use of GAPs

Recent Listeria and E. coli outbreaks in cantaloupes and strawberries are bringing greater scrutiny of direct market growers’ on-farm food safety practices. Hultberg et al. (p. 83) used a mail survey and farm visits to assess Minnesota vegetable growers’ compliance to good agricultural practices (GAPs). Most of the growers farm on 15 acres or less and raise 10 or more types of vegetables. Over 65% of the survey respondents reported compliance to GAPs, but were lacking in specific areas including treating wash and processing water, keeping animals out of production fields, and sanitizing harvesting tools and containers.

Winter Application of Glyphosate on Warm Season Turfgrasses

In transitional environments, turf managers and sod producers of warm season grasses face the issue of winter annual weeds that can dominate dormant turf stands through the winter until late spring. Postemergence herbicides are used extensively to kill winter annual weeds in warm season turfgrasses; however, application timing is critical as spring green-up can be inhibited. Rimi et al. (p. 131) found that an application of glyphosate in February at 1 lb/acre effectively controlled winter weeds in ‘Zeon’ manilagrass and ‘Yukon’ bermudagrass without negatively affecting green-up. In contrast, spring green-up of ‘Companion’ zoysiagrass was delayed by the application of glyphosate.

Shoot Regeneration In Vitro by Huckleberry and Bilberry

Debnath and Barney (p. 106) developed a plant regeneration protocol for cascade huckleberry, mountain huckleberry, and oval-leaf bilberry using leaf or stem segments. Zeatin at 9.1 to 13.7 μM supported the best bud and shoot regeneration but at 2.3 to 4.6 μM, enhanced shoot elongation. Proliferated shoots were rooted on the same medium, but without any plant growth regulators. Rooted plantlets were transferred to a 2 peat :1 perlite (v/v) medium for acclimatization and eventually established in the greenhouse with 75% to 90% survival rate.

Brassica Cover Crops and Hazelnut Mulch Impact Weeds

Appropriate weed management is a critical component of profitable hazelnut production. Mennan and Ngouajio (p. 99) demonstrated that cover crops like rape, field mustard, and oriental mustard incorporated in the soil at flowering stage reduced weed density, weed dry weight, and the number of weed species as compared with the fallow system. Likewise, hazelnut husk mulch was highly effective at controlling weeds up to 180 days after application and reduced total weed dry weight by up to 80% at the end of the season.