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T.R. Roper, D.L. Mahr and P. Kaarakka

Cranberry Crop Manager is a predictive software package for commercial cranberry growers. The package consists of linked modules. Predictive models for insect, disease, and weed development are the most important features. With appropriate weather and scouting information the models will make control or no control recommendations. To support the predictive models the program will maintain weather records of air temperatures, evapotranspiration, irrigation, and rainfall. Data can be imported or entered by hand. The program will maintain bed records including pesticide applicators, pesticide and fertilizer applications, and scouting reports. Output options include screen or printed reports or data export. An electronic encyclopedia of cranberry disease, insect and weed pests on CD will accompany the package. Minimum computer requirements are 486 CPU, 6 MB RAM, 6 MB hard drive space.

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T.R. Roper, A.R. Krueger, C.J. DeMoranville, N. Vorsa, J. Hart and A.P. Poole

Nitrogen fertilizer application is a universal practice among cranberry growers. Cranberries only use ammonium nitrogen sources. This study was undertaken to discover how quickly cranberries in the field would take up fertilizer-derived ammonium nitrogen. Ammonium sulfate labeled with 15N was applied in field locations in Oregon, Massachusetts, New Jersey, and Wisconsin. Samples of current season growth were collected daily for 7 days beginning 24 hours after fertilizer application. In all cases 15N was detectable in the plants from treated plots by 24 hours following application. Additional nitrogen was taken up for the next 3 to 5 days depending on the location. With the exception of Oregon, the maximum concentration of 15N was found by day 7. Oregon was the coolest of the sites in this research. To determine a temperature response curve for N uptake in cranberry, cranberry roots were exposed to various temperatures in aeroponics chambers while vines were at ambient greenhouse temperatures. The optimum temperature for N uptake by cranberry vines was 18 to 24 °C. This research suggests that ammonium fertilizers applied by growers and irrigated into the soil (solubilized) are taken up by the plant within 1 day following application. Soil and root temperature is involved in the rate of N uptake.

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B.C. Strik, T.R. Roper, C.J. DeMoranville, J.R. Davenport and A.P. Poole

Biennial bearing has long been thought to occur in cranberry (Vaccinium macrocarpon Ait). Researchers have shown that percent return bloom on fruiting uprights can range from 12% to 65% depending on year, bed vigor and cultivar. Resource limitation and/or hormonal factors in a fruiting upright may be related to flower bud initiation and, thus, percent return bloom the following year. This research was undertaken to determine the extent of biennial bearing by cranberry cultivar and growing region. Seven cultivars were studied; three found in all states (MA, NJ, WI, OR), two common to MA and NJ, and two different cultivars in WI and OR representing cultivars commercially grown in these areas. In the fall or winter of 1989/1990 six 2-m transects were randomly selected within a cranberry bed for each cultivar. Along the transect, 60 uprights that fruited in 1989 were tagged. In the summer of 1990, fifty of the uprights will be sampled to determine percent return bloom and percent set.

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B.C. Strik, T.R. Roper, C.J. DeMoranville, J.R. Davenport and A.P. Poole

Biennial bearing has long been thought to occur in cranberry (Vaccinium macrocarpon Ait). Researchers have shown that percent return bloom on fruiting uprights can range from 12% to 65% depending on year, bed vigor and cultivar. Resource limitation and/or hormonal factors in a fruiting upright may be related to flower bud initiation and, thus, percent return bloom the following year. This research was undertaken to determine the extent of biennial bearing by cranberry cultivar and growing region. Seven cultivars were studied; three found in all states (MA, NJ, WI, OR), two common to MA and NJ, and two different cultivars in WI and OR representing cultivars commercially grown in these areas. In the fall or winter of 1989/1990 six 2-m transects were randomly selected within a cranberry bed for each cultivar. Along the transect, 60 uprights that fruited in 1989 were tagged. In the summer of 1990, fifty of the uprights will be sampled to determine percent return bloom and percent set.

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T.R. Roper, K.D. Patten, C.J. DeMoranville, J.R. Davenport, B.C. Strik and A.P. Poole

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C.J. DeMoranville, T.R. Roper, K.D. Patten, J.R. Davenport, B.C. Strik and A.P. Poole

Biennial bearing of uprights has been documented for cranberry (Vaccinium macrocarpon Ait.). Percent return bloom (%RB) may vary from 14% to 74% depending on cultivar and growing region. Floral initiation for the following season in cranberry takes place during the same time period as flowering and fruit set for the current season. This research was undertaken to document the effect of fruiting or not fruiting in the previous year on %RB and %RF (return fruit) in two cultivars (Stevens and Ben Lear) and five growing regions (MA, NJ, WI, OR, WA). Previous year fruiting caused a reduction in %RB compared to non-fruiting in the previous year. The effect on %RF was even greater. For `Ben Lear', uprights that fruited in 1990 had 31%RB and 22%RF while those that did not fruit in 1990 had 67%RB and 54%RF. Both %RB and %RF in 1991 were about 49% lower for `Stevens' which fruited in 1990 than those that did not fruit in 1990. It is still not clear whether biennial bearing in cranberry uprights is a function of hormonal interaction and regulation or of resource limitation or both.

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S.S. Miller, R.W. McNew, B.H. Barritt, L. Berkett, S.K. Brown, J.A. Cline, J.M. Clements, W.P. Cowgill, R.M. Crassweller, M.E. Garcia, D.W. Greene, G.M. Greene, C.R. Hampson, I. Merwin, D.D. Miller, R.E. Moran, C.R. Rom, T.R. Roper, J.R. Schupp and E. Stover

Cultivar and planting site are two factors that often receive minimal attention, but can have a significant impact on the quality of apple (Malus ×domestica) produced. A regional project, NE-183 The Multidisciplinary Evaluation of New Apple Cultivars, was initiated in 1995 to systematically evaluate 20 newer apple cultivars on Malling.9 (M.9) rootstock across 19 sites in North America. This paper describes the effect of cultivar and site on fruit quality and sensory attributes at a number of the planting sites for the 1998 through 2000 growing seasons. Fruit quality attributes measured included fruit weight, length: diameter ratio, soluble solids concentration (SSC), titratable acidity (TA), flesh firmness, red overcolor, and russet. Fruit sensory characteristics rated included crispness, sweetness, and juiciness, based on a unipolar intensity scale (where 1 = least and 5 = most), and acidity, flavor, attractiveness, and desirability based on a bipolar hedonic scale (where 1 = dislike and 5 = like extremely). All fruit quality and sensory variables measured were affected by cultivar. The two-way interaction of cultivar and planting site was significant for all response variables except SSC, TA, russet, crispness, and sweetness ratings. The SSC: TA ratio was strongly correlated with sweetness and acidity sensory rating, but was weakly correlated with flavor rating. The results demonstrate that no one cultivar is ideally suited for all planting sites and no planting site is ideal for maximizing the quality of all apple cultivars.