in HortTechnology

High-density Peach Production Systems Are More Economical

The lack of dwarfing rootstocks for peach has led to cultural and genetic approaches that reduce tree size and vegetative growth to establish high-density plantings. Glenn et al. (p. 720) evaluated eight production systems with interactions of pruning strategies, sod management, tree densities, and standard vs. pillar peach architecture from 1999 to 2007. The use of sod management reduced pruning time and costs, but the reduction of crop load reduced net return. High-density plantings in large vegetation-free areas had greater economic return than low-density plantings.

Planting Sweetpotato Using Root Pieces

Sweetpotato is vegetatively propagated using cuttings (slips), which is demanding in terms of time, expense, and labor. An alternative propagation method is to use small roots, or pieces of roots, similar to the system used for potato. Root-piece planting in sweetpotato has been investigated since the 1940s, but is not used commercially. George et al. (p. 703) reviewed the published literature and concluded that by using suitable clones and cultural management methods, root pieces can produce yields comparable to slips. Further research is needed to determine if root-piece planting is a viable alternative to slips in commercial sweetpotato production.

Drought Resistance of Warm-season Turfgrasses Grown in Turkey

Six warm-season turfgrass species and several of their varieties were evaluated for resistance to drought under the Mediterranean climate of Turkey. One year after establishment, turf was subjected to drought stress for 90 days, which was followed by resumption of irrigation for recovery of the turf. Severmutlu et al. (p. 726) observed that ‘SWI1045’ (Contessa®) bermudagrass, ‘SWI1044’ bermudagrass, and ‘Cody’ buffalograss possessed superior drought resistance with acceptable turfgrass quality up to 30 days under drought stress.

Baby Leaf Lettuce Yield Shaped by Seasonal and Grower-induced Temperatures

Fall and spring baby lettuce production is increasingly popular, but is hampered by an incomplete understanding of microenvironment and management strategy effects on yield and other variables. Seasons and strategies can create dynamic microenvironments featuring rapid and sometimes extreme temperature and light fluctuations over narrow time frames. Moreover, aerial and root-zone temperatures tend to affect growth differently. Using fall- and spring-time passive aerial and active root-zone heating in outdoor and high tunnel settings to establish contrasting baby lettuce microenvironments, Bumgarner et al. (p. 737) affirmed that temperature can drive productivity and that improved temperature management tools and strategies are needed.

Potential Drift from a Citrus Herbicide Applicator

Vanella et al. (p. 745) evaluated a drift sampling system for herbicide applications. Developing a computational procedure, they tested the effects and interactions of sprayer nozzle type, ground speed, and spray shield in terms of a drift potential index (DPI). Ground speed was the main factor affecting the DPI. Both nozzle types tested (XR8002VS, TT11002VP) showed higher DPI at faster speeds. There was 56% reduction in DPI between the worst ((XR8002VS, 6 km·h–1, no shield) and best (TT11002VP, 3 km·h–1, with shield) application scenarios. Results were significantly affected by wind velocity normalized to the sprayer travel direction.

Competition among Viticulture Programs in the U.S.

Junior college (JC) and community college (CC) programs offering viticulture and enology courses have proliferated in recent years in many states. Stafne and Kelsey (p. 789) surveyed 69 land-grant (LG) specialists who may interact with JC and CC programs offering viticulture and enology courses. Results indicated that most LG horticulture/viticulture programs are not interacting with the JC/CC programs. Many LG respondents do not see the JC/CC programs as competitors to their programs; however, documented actions of JC/CC programs would dictate otherwise. Land-grant viticulture and enology programs no longer should consider JC/CC programs as non-competitors for funding and clientele interaction.

Mid-winter Stone Fruit Flower Bud Damage in New Mexico

Yao (p. 767) observed winter damage on flower buds of peach, apricot, plum, and cherry in New Mexico. After –7.2 °F on 1 Jan. 2011, the peach live flower buds ranged from 11% for ‘Blazingstar’ to 87% for ‘China Pearl’. When the temperature dropped to –11.9 °F on 3 Feb., all 12 peach varieties had less than 1% live buds. For apricot, the flower buds on 1-year-old shoots were hardier than those on 2-year-old or older wood. The stone fruit flower bud winter hardiness order was: peach < japanese plum and apricot < european plum and sweet cherry < tart cherry.

Responses of Lettuce Varieties to Insect Pests in Southern Florida

Banded cucumber beetle, serpentine leafminer, and aphids are important insect pests of lettuce in southern Florida. Use of host-plant resistance is an environmentally sound method to control the insects. Four romaine and three iceberg lettuce varieties were evaluated for responses to the insects using natural infestations in the field experiments. Lu et al. (p. 773) observed significant differences in responses to insect infestations among varieties. The romaine variety 70096 was found to be resistant to banded cucumber beetle and could be used in the integrated pest management program for control of the insect to protect the lettuce crop in Florida.

Healing Chamber Design Impacts the Survival of Grafted Vegetables

After grafting, vegetable plants are held in healing chambers that maintain high relative humidity (RH) and optimal temperatures. Johnson and Miles (p. 752) evaluated the RH, temperature, and survival of grafted eggplant, tomato, and watermelon in three healing chambers with varying dimensions, materials, and misting treatments. Higher RH was observed in the design with a plastic cover and the lowest internal volume. A humidifier did not result in higher RH than occasional hand misting. High RH is not essential for high tomato survival (> 95%), whereas eggplant survival increased with higher RH.

Irrigation of Tomato with Wetland-treated Water

Tomato plants were irrigated with treated water from three types of artificial wetlands (AWs). Gruyer et al. (p. 759) showed that the use of AW-treated waters reduced the root Pythium population by up to 100%. In vitro trials suggested that microbial activity played an important role in Pythium suppression. However, root dry weights of plants irrigated with treated water was 56% lower than in control plants, while their shoot : root ratio increased by two times. Organic compounds present in treated waters may explain this inhibiting root growth effect.

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