Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: John M. Enns x
  • User-accessible content x
Clear All Modify Search
Free access

Fumiomi Takeda, Stan C. Hokanson and John M. Enns

Strawberry (`Chandler') plants were grown in a greenhouse hydroponic culture system from 28 Apr. to 20 July to produce runners (stolons) with several daughter plants. By mid-July, each `Chandler' plant had developed about 30 daughter plants on 12 runners with 1 to 6 daughter plants on each runner. Daughter plants varied in weight from <0.9 to >10 g. Daughter plant weight and position on the runner affected new root development on plug plants during the first 7 days under mist irrigation. At 3 weeks, 87% of daughter plants that weighed <0.9 g and at least 96% of daughter plants that weighed >1.0 g were rated acceptable for field transplanting, respectively. The percentage of daughter plants from second to tenth node position that were rated acceptable for field planting ranged from 98% to 88%, respectively. Runner production in the fall was not affected by either position on the runner or weight at the time of daughter plant harvest. But, larger daughter plants produced more branch crowns than did smaller daughter plants in the fall. Transplant survival in the field was 100%. In the spring, `Chandler' plants produced a 10% greater yield from daughter plants that weighed 9.9 g compared to those that weighed only 0.9 g.

Full access

Brent L. Black, John M. Enns and Stan C. Hokanson

Anticipating the phaseout of methyl bromide, the USDA-ARS small fruit breeding program at Beltsville, Md., discontinued soil fumigation in strawberry breeding and selection trials in the mid 1990s. To address resulting weed and pathogen pests, a modified or advanced matted row system was developed. This system uses matted row-type culture, established on raised beds with subsurface drip irrigation and organic mulch. The mulch is the residue of a killed cover crop that fixes some nitrogen and provides an economical, biodegradable mulch for suppressing weeds and reducing erosion. Since 1996, the small fruit breeding program has conducted replicated performance trials on both advanced matted row and a regional adaptation of annual hill plasticulture. Both of these systems were managed without methyl bromide fumigation or fungicide application. Data from these trials were used to compare advanced matted row and plasticulture for yield, fruit quality and harvest season. Yield for the two systems was genotype dependent, and the advanced matted row system had later production and slightly lower fruit quality.

Restricted access

Kim S. Lewers, John M. Enns and Patricia Castro

Free access

John L. Maas, John M. Enns, Stan C. Hokanson and Richard L. Hellmich

Larvae of several insects injure and kill strawberry (Fragaria ×ananassa Duchesne) plants by burrowing into and hollowing out plant crowns. Occasionally, these infestations are serious enough to cause heavy economic losses to fruit producers and nursery plant growers. In 1997 in Beltsville, Md., we observed wilting and dying mature plants and unrooted runner plants in two experimental strawberry plantings. Injury by larvae was extensive; large cavities occurred in crowns, and the central pith tissues were removed from stolons and leaf petioles. Often, insect frass was seen at entrance holes. Larvae removed from hollowed-out parts of injured plants were identified as the European corn borer (Ostrinia nubilalis Hübner) in their fifth instar stage. Their presence in this instance also was associated with a cover crop of millet [Setaria italica (L.) P. Beauv., `German Strain R'] planted between the strawberry rows for weed suppression. This is the first published report of the European corn borer attacking strawberry. Although this insect may occur only sporadically in strawberry plantings, it may become important in the future. Growers and other professionals should become aware of this new strawberry pest and recognize that its management in strawberry will be different from management of other crown-boring insects.

Full access

John L. Maas, John M. Enns, Stan C. Hokanson and Richard L. Hellmich

Larvae of several insects injure and kill strawberry (Fragaria ×ananassa Duchesne) plants by burrowing into and hollowing out plant crowns. Occasionally, these infestations are serious enough to cause heavy economic losses to fruit producers and nursery plant growers. In 1997 in Beltsville, Md., we observed wilting and dying mature plants and unrooted runner plants in two experimental strawberry plantings. Injury by larvae was extensive; large cavities occurred in crowns, and the central pith tissues were removed from stolons and leaf petioles. Often, insect frass was seen at entrance holes. Larvae removed from hollowed-out parts of injured plants were identified as the European corn borer (Ostrinia nubilalis Hübner) in their fifth instar stage. Their presence in this instance also was associated with a cover crop of millet [Setaria italica (L.) P. Beauv., `German Strain R'] planted between the strawberry rows for weed suppression. This is the first published report of the European corn borer attacking strawberry. Although this insect may occur only sporadically in strawberry plantings, it may become important in the future. Growers and other professionals should become aware of this new strawberry pest and recognize that its management in strawberry will be different from management of other crown-boring insects.

Free access

Stan C. Hokanson, Fumiomi Takeda, John M. Enns and Brent L. Black

Tissue-culture derived mother plants were established in a greenhouse suspended-gutter, nutrient-film technique growing system to evaluate runner tip productivity in the system. Effects of cultivar (`Allstar', `Chandler', `Latestar', `Northeaster', and USDA selection B 27) and duration (0, 1, or 2 months) of cold storage at 1 °C on tip viability, rooting success, and performance in fruit production were determined. The average number and weight of runner tips produced in the gutter production system, the capacity of runner tips to form cohesively rooted plug plants, and the number and length of adventitious roots produced by runner tips varied significantly among the cultivars and the three storage durations (0, 1, or 2 months). In the field, plants produced from runner tips stored for 2 months produced more runners than plants produced from freshly harvested runner tips. Crown number differed among the cultivars, but was not affected by cold storage treatment. No treatment differences were noted for the fruit harvest parameters evaluated. The results suggest that the transplants derived from mother plants grown in a greenhouse-based soilless system can be useful for annual plasticulture strawberry production in colder climates. Although long periods of cold storage of runner tips resulted in lower tip-to-transplant conversion ratios, field performance of transplants was not adversely affected. Additional research is needed to improve greenhouse strawberry production practices for increasing runner output and storage conditions that maintain the integrity of cold-stored runner tips. Without these improvements it is unlikely that soilless runner tip production will become a widely accepted technique that would replace the field nursery tip production method currently used by commercial strawberry propagators.

Restricted access

Kim S. Lewers, Patricia R. Castro, John M. Enns, Stan C. Hokanson, Gene J. Galletta, David T. Handley, Andrew R. Jamieson, Michael J. Newell, Jayesh B. Samtani, Roy D. Flanagan, Barbara J. Smith, John C. Snyder, John G. Strang, Shawn R. Wright and Courtney A. Weber