The Pacific Northwest region of the United States is an important growing region for the production of blueberry ( V. corymbosum L.), blackberry ( Rubus L. subgenus Rubus , Watson), raspberry ( R. idaeus L.), and strawberry ( Fragaria
Amanda J. Vance, Patrick Jones and Bernadine C. Strik
E.E. Albregts, G.A. Clark, C.D. Stanley, F.S. Zazueta and A.G. Smajstrla
Strawberry (Fragaria ×ananassa Duch.) was grown for two seasons with microirrigation. Preplant fertilizer treatments of zero, one, two, three, and four times the basic N and K rate of 17 and 15 kg·ha–1, respectively, were applied each season. Additional N and K were applied twice weekly through the microirrigation system at 1.12 and 0.92 kg·ha–1·day–1, respectively. Total marketable fruit yield and marketable fruit per plant were not affected by preplant fertilizer rate. The percentage of marketable fruit increased with increased preplant fertilizer to the 51N–45K (three times basic rate) kg·ha–1 rate the first season. Average fruit weight increased the first season but decreased the second season with increased preplant fertilizer. Plants were larger the first season in treatments receiving preplant fertilizer.
José M. López-Aranda, Carmen Soria, José F. Sánchez-Sevilla, Josefa Gálvez, Juan J. Medina, Antonio Arjona, José I. Marsal and Rafael Bartual
Public and private institutions in Spain are increasing strawberry (Fragaria ×ananassa Duch.) breeding efforts to obtain new strawberry cultivars well-adapted to growing conditions in Huelva and other Spanish areas, such as Valencia on the eastern Spanish coast. The new `Medina' is a short-day cultivar that is remarkable for its high production of first quality fruits, and large fruits. `Medina' has also an appropriate harvest calendar for the economic interest of the Huelva area.
John R. Duval, Craig K. Chandler, Daniel E. Legard and Peter Hicklenton
Transplant quality can have a major effect on the productivity of many crops. Bare-root, green-top transplants for Florida winter strawberry (Fragaria ×ananassa) production are produced mainly in highlatitude (>42° N) nurseries. Mechanical digging machines are used to remove plants from the soil at these nurseries before transport to production fields in Florida. In the course of this operation, crowns, petioles, and leaves may be crushed and broken. Machine and hand-dug bare-root transplants of `Camarosa' and `Sweet Charlie' were obtained from a Nova Scotia, Canada nursery, planted at the Gulf Coast Research and Education Center, Dover, Fla. field facility on 2 Nov. 1999 and 10 Oct. 2000, and grown using standard annual-hill production practices. Plots were harvested twice weekly beginning 5 Jan. 2000 and 15 Dec. 2000. Hand-dug transplants produced significantly higher monetary returns both seasons. Therefore, fruit producers may consider paying the higher cost associated with changes in harvesting and packing operations needed to reduce damage to transplants.
D.J. Makus and J.R. Morris
Supplemental Ca was supplied to `Cardinal' and `Fern' strawberry (Fragaria ×ananassa Duch.) plants grown in an Enders clayey silt loam soil as a foliar spray of Ca glutarate, as soil incorporated gypsum, as fertigated calcium nitrate (CaNO3), or as a combination of the above. Controls received no Ca. Individual fruits were partitioned into six parts: proximal, distal, inner and outer receptacle, and proximal and distal achenes. Mineral nutrient concentrations (dry mass basis) found in the inner and outer receptacle, and in achenes were, in descending order, K, P, Ca, Mg, Al, Na, Fe, Mn, Zn, B, and Cu; K, P, Ca, Mg, Na, Mn, Fe, Zn, Al, B, and Cu; and Ca, P, Mg, K, Na, Fe, Mn, Zn, Al, Cu, and B, respectively. Many nutrients, including Ca, tended to occur in greater concentrations in the proximal portion of the fruit than in the distal part. With the exception of Al, nutrient concentration gradients were lowest in the inner receptacle. Fruit Ca concentrations were highest in achenes and lowest in inner receptacle tissue. Differences among cultivars in Ca concentration were found in achenes but not in receptacle tissue. Calcium treatment had no effect on receptacle tissue Ca concentrations, regardless of cultivar, but CaNO3 and combination treatments increased Ca concentrations in the achenes in the proximal half of `Cardinal' fruit. Concentrations of all other nutrients except Mn were unaffected by supplemental Ca treatments.
Eric B. Bish, Daniel J. Cantliffe and Craig K. Chandler
The demand for plug transplants by the Florida winter strawberry (Fragaria ×ananassa Duch.) industry may increase as water conservation during plant establishment becomes more important and the loss of methyl bromide fumigant makes the production of bare-root transplants more problematic. A study was conducted during the 1995-96 and 1996-97 seasons to determine the effect of container size and temperature conditioning on the plant growth and early season fruit yield of `Sweet Charlie' strawberry plants. Plants in containers of three sizes (75, 150, and 300 cm3) were grown in one of two temperature-controlled greenhouses (35 °C day/25 °C night or 25 °C day/15 °C night) for the 2 weeks just prior to transplanting into a fruiting field at Dover, Fla. Plants exposed to the 25/15 °C treatment had significantly higher average root dry weights at planting in 1995 and 1996 than did plants exposed to the 35/25 °C treatment. Plants exposed to the 25/15 °C treatment also had higher average fruit yields than the plants exposed to the 35/25 °C treatment (48% and 18% higher in 1995-96 and 1996-97, respectively). The effect of container size on plant growth and yield was variable. Plants propagated in the 150- and 300-cm3 containers tended to be larger (at planting) than the plants propagated in the 75-cm3 containers, but the larger container sizes did not result in consistently higher yields.
Eric B. Bish, Daniel J. Cantliffe and Craig K. Chandler
A greenhouse hydroponic system, which uses suspended plastic troughs, was found to be an efficient system for the production of high quality strawberry (Fragaria ×ananassa) plantlets. In this system micropropagated mother plants of `Oso Grande' and `Sweet Charlie' produced an average of 84 and 80 daughters per mother plant, respectively, in 1996, at a plant density of 3 mother plants/ft2 (32 mother plants/m2). Nearly 100% of the plantlets harvested from the system were successfully rooted in plug trays, and showed no symptoms of leaf or crown diseases.
K. Mattas, M. Bentes, G. Paroussi and I. Tzouramani
The financial effectiveness of a soilless vertical bag system of hydroponics culture was evaluated for off-season strawberry (Fragaria ×ananassa Duch) production in heated greenhouses in northern Greece. Financial analysis revealed that the implementation of this soilless culture system instead of the traditional production system under plastic tunnels would not be profitable for Greek farmers due to its high initial investment and high fuel consumption. Sensitivity analysis indicated the importance of product price in affecting the magnitude of benefits, confirming the interest of farmers to produce off-season strawberries to market them when prices are likely to be higher. In addition, yield increase will have a positive effect upon farmers' income.
Tarja Hietaranta and Minna-Maria Linna
The firmness of five strawberry (Fragaria×ananassa Duch.) varieties was determined by penetrometric method using a motorized materials testing device equipped with a 100-N load cell and a probe 6.4 mm (0.252 inches) in diameter. Maximum and mean forces and instant of yield point were recorded with the aim of testing the suitability of these three parameters for the assessment of fruit firmness, i.e., handling and transportation tolerance. The maximum and mean force data revealed significant differences among varieties, but instant of yield point was not reliable measurement in this test arrangement. Maximum force was the best parameter for the assessment of firmness.
Mette Larsen and Christopher B. Watkins
Firmness and aroma composition of strawberry fruit (Fragaria ×ananassa Duch. cv. Pajaro) stored in air or treated with 20% CO2 for up to 12 days at 0C were analyzed upon removal from storage. Fruit firmness increased after 2 days in CO2, while the composition of aroma compounds in the fruit was unaffected at this time. Ethanol and ethyl hexanoate accumulated after 3 days during high CO2 treatment, but these compounds usually decreased during subsequent cold storage in air. Ethyl butanoate and ethyl acetate also accumulated but continued to increase after 6 and 9 days of CO2 storage, respectively. This study suggests that treatment of strawberry fruit with CO2 after harvest, followed by air storage at 0C, can maintain firmness while minimizing off-flavor development.