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Bernadine Strik, Timothy Righetti, and Gil Buller

Fertilizer nitrogen (FN) recovery, and changes in nitrogen (N) and dry weight partitioning were studied over three fruiting seasons in June-bearing strawberry (Fragaria ×ananassa Duch. `Totem') grown in a matted row system. Fertilizer nitrogen treatments were initiated in 1999, the year after planting. The standard ammonium nitrate N application at renovation (55 kg·ha-1 of N) was compared to treatments where additional N was applied. Supplemental treatments included both ground-applied granular ammonium nitrate (28 kg·ha-1 of N) applied early in the season and foliar urea [5% (weight/volume); 16 kg·ha-1 of N] applied early in the season and after renovation. When labeled N was applied (eight of nine treatments) it was applied only once. The impact of no FN from the second through the third fruiting season was also evaluated. Fertilizer nitrogen treatment had no impact on total plant dry weight, total plant N, yield or fruit quality from the first through the third fruiting seasons. Net dry matter accumulation in the first fruiting season was 2 t·ha-1 not including the 4 t·ha-1 of dry matter removed when leaves were mowed during the renovation process. Seasonal plant dry weight and N accumulation decreased as the planting aged. Net nitrogen accumulation was estimated at 40 kg·ha-1 from spring growth to dormancy in the first fruiting season (including 30 kg·ha-1 in harvested fruit, but not including the 52 kg·ha-1 of N lost at renovation). Recovery of fertilizer N ranged from 42% to 63% for the broadcast granular applications and 15% to 52% for the foliar FN applications, depending on rate and timing. Fertilizer N from spring applications (granular or foliar) was predominantly partitioned to leaves and reproductive tissues. A large portion of the spring applied FN was lost when plants were mowed at renovation. Maximum fertilizer use efficiency was 42% for a granular 55 kg·ha-1 application at renovation, but declined to 42% just before plant growth the following spring, likely a result of FN loss in leaves that senesced. In June, ≈30% of the N in strawberry plants was derived from FN that was applied at renovation the previous season, depending on year. This stored FN was reallocated to reproductive tissues (22% to 35%) and leaves (43% to 53%), depending on year. Applying fertilizer after renovation increased the amount of remobilized N to new growth the following spring. The following June, 15% of plant nitrogen was derived from fertilizer applied at renovation 2 years prior.

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Ralph Scorza and Margaret Pooler

Doubled haploid peach [Prunus persica (L.) Batsch] lines were cross-pollinated to produce F1 hybrids. F1 hybrids were evaluated at 3, 7, 8, and 9 years after field planting for tree growth as measured by trunk cross-sectional area, and for fruit production as measured by total weight, total number, and production per unit trunk cross-sectional area. Fruit quality of most F1 hybrids was within the range of quality observed in progeny of standard peach cultivars, and tree growth and productivity were similar to those of standard cultivars. F1 hybrids present the possibility of developing scion varieties that can be produced from seed, thus eliminating the need for grafting scions onto rootstocks in situations where specific, adapted rootstocks are not necessary. They could also be used to develop genetically uniform seed-propagated rootstocks. The use of doubled haploid-derived F1 peach hybrids, however, would require reliable, efficient production techniques.

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Francisco Doñas-Uclés, Diego Pérez-Madrid, Celia Amate-Llobregat, Enrique M. Rodríguez-García, and Francisco Camacho-Ferre

., 2010 ), as with the case of cucurbits, the main family of grafted plants worldwide ( Cohen et al., 2007 ). In spite of the fact that the use of the adequate rootstock through grafting can be an alternative strategy to avoid or reduce yield losses caused

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Paul E. Blom and Julie M. Tarara

Given the finite resources of juice processors and wineries, and the perishable nature of the crop, accurate estimation of yield in grapes is crucial for optimal scheduling and processing of the harvest. Difficulties associated with yield estimation

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Tadahisa Higashide, Yuya Mochizuki, Takeshi Saito, Yasushi Kawasaki, Dong-Hyuk Ahn, and Akio Ohyama

Yields of greenhouse tomatoes ( Solanum lycopersicum L.) in the Netherlands have doubled over the past 30 years ( KIG, 2005 ), whereas those in Japan have not increased since the 1980s, remaining much less than ≈30 kg·m −2 per year. Although the

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David M. Eissenstat, Denise Neilsen, Gerry H. Neilsen, and Thomas S. Adams

, Canada. Investigations included root growth, shoot water relations, tree branch growth, and fruit yield. We hypothesized that restricted irrigation would increase root growth in the irrigated portion of the soil, and reduce aboveground vegetative growth

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Job Teixeira de Oliveira, Rubens Alves de Oliveira, Fernando França da Cunha, Isabela da Silva Ribeiro, Lucas Allan Almeida Oliveira, and Paulo Eduardo Teodoro

, 2018 ). Water is the factor that most often affects the development, yield, and quality of garlic. Soil water deficiency mainly compromises plant development and bulb yield, whereas excess impairs quality and conservation ( Costa et al., 1993 ). Because

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William B. Thompson, Jonathan R. Schultheis, Sushila Chaudhari, David W. Monks, Katherine M. Jennings, and Garry L. Grabow

percentage of no. 1 grade sweetpotato roots that result in excellent economic return. For improved storage root yield and quality, growers must closely follow recommended growing practices in the production field ( Kemble, 2013 ). However, production

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Xinhua Yin, Jinhe Bai, and Clark F. Seavert

The mid-Columbia region in Oregon produces 40% of the “winter” pears and 20% of the ‘Bartlett’ “summer” pears in the United States. Pear production is highly dependent on nitrogen (N) and phosphorus (P) fertilization to achieve optimum fruit yield

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Bruce D. Lampinen, Vasu Udompetaikul, Gregory T. Browne, Samuel G. Metcalf, William L. Stewart, Loreto Contador, Claudia Negrón, and Shrini K. Upadhyaya

with mechanically harvested yield data. Materials and methods Mobile platform description. To measure PAR intercepted by the plant canopy, a utility vehicle (model 610 Mule; Kawasaki Heavy Industries, Tokyo) was fitted with a PAR measurement system