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Theodore J.K. Radovich, Archana Pant, Ian Gurr, Ngyuen V. Hue, Jari Sugano, Brent Sipes, Norman Arancon, Clyde Tamaru, Bradley K. Fox, Kent D. Kobayashi and Robert Paull

Soils generally have insufficient amount of nutrients, such as N, phosphorus (P), and K for crops to reach the maximum yield. Therefore, farmers apply soil amendments, including commercial or organic fertilizers that are rich in nutrients to ensure

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Darby S. Kellum, Manoj K. Shukla, John Mexal and Sanjit Deb

emissions are a direct function of moisture content fluctuations and fertilization events. Materials and Methods Experimental sites. We established sites at two pecan [ C. illinoinensis (Wangenh.) K. Koch] orchards: New Mexico State University Leyendecker

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K. Yonemori, A. Sugiura, K. Tanaka and K. Kameda

This research was supported, in part, by grant-in-aid (no. 01480046) from the Ministry of Education, Science and Culture, Japan. We gratefully acknowledge the critical reading and suggestions about the manuscript done by K. Ryugo, Dept. of Pomology

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Amir M. González-Delgado, Manoj K. Shukla and Brian Schutte

Pecan [ Carya illinoinensis (Wangenh.) K. Koch] is an important crop of southern New Mexico, USA. Appropriate management practices are required to maintain the quality and yield of pecan while conserving water resources ( Andales et al., 2006

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T.K. Hartz, G. Miyao, R.J. Mullen, M.D. Cahn, J. Valencia and K.L. Brittan

A survey of 140 processing tomato (Lycopersicon esculentum Mill.) fields in central California was conducted in 1996-97 to examine the relationship between K nutrition and fruit quality for processing. Quality parameters evaluated were soluble solids (SS), pH, color of a blended juice sample, and the percent of fruit affected by the color disorders yellow shoulder (YS) or internal white tissue (IWT). Juice color and pH were not correlated with soil K availability or plant K status. SS was correlated with both soil exchangeable K and midseason leaf K concentration (r = 0.25 and 0.28, p < 0.01) but the regression relationships suggested that the impact of soil or plant K status on fruit SS was minor. YS and IWT incidence, which varied among fields from 0% to 68% of fruit affected, was negatively correlated with K status of both soil and plant. Soil exchangeable K/√Mg ratio was the measure of soil K availability most closely correlated with percent total color disorders (YS + IWT, r = -0.45, p < 0.01). In field trials conducted to document the relationship between soil K availability and the fruit color disorders, soil application of either K or gypsum (CaSO4, to increase K/√Mg ratio) reduced YS and total color disorders. Multiple foliar K applications were effective in reducing fruit color disorders at only one of two sites. In no field trial did K application improve yield, SS, or juice color.

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Timothy K. Broschat

Greenhouse-grown Tapeinochilus ananassae Hassk. were fertilized with 1110, 2220, or 4440 g of Osmocote 17N–3P–10K/m2 per year for 4 years. Plants receiving the medium rate of fertilizer produced the most flowers, while the highest fertilization rate resulted in the fewest. Flower stalk length decreased each year after planting, but cutting back the vegetative shoots to the ground resulted in increased flower stalk length the following year. Fertilization with the highest rate resulted in reduced flower postharvest life, but floral preservatives and ethylene inhibitors had no effect on postharvest life.

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Timothy K. Hartz, P. R. Johnstone, E. Williams and R.F. Smith

( Olsen and Sommers, 1982 ) was used to estimate soil P availability. Soil-exchangeable K, Ca, and Mg were measured by atomic emission spectrometry (AES) following ammonium acetate extraction ( Thomas, 1982 ). DTPA-extractable soil Zn, Mn, Fe, and Cu were

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H.K. Wutscher

Three trees each of `Valencia' orange (Citrus sinensis L. Osbeck) on rough lemon (C. limon L. Burm. f.) rootstocks that had been grown in solution culture since July 1989 were grown in two solutions from Oct. 1995 to Sept.1996. Solution 1 was a soil extract made by boiling field soil (1:2 soil:water) for 20 min and filtering. Solution 2 was a complete nutrient solution. The solutions were analyzed every 7 days and changed every 28 days. At each solution change, the newly prepared solutions were analyzed for 11 elements and their depletion was determined by weekly analysis. Nearly all the N, K, and Mn in Solution 1 was absorbed in the first 7 days after each solution change; in Solution 2, N and Mn were also absorbed in 7 days, but K absorption was variable; single trees sometimes needed 4 weeks to absorb all the potassium. Calcium and Mg were never completely absorbed and in contrast to Mn, traces of Fe, Zn, and Cu remained in both solutions after 4 weeks.

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Timothy K. Broschat

Five species of tropical ornamental plants—artillery fern (Pilea serpyllacea), pleomele (Dracaena reflexa), fishtail palm (Caryota mitis), areca palm (Dypsis lutescens), and sunshine palm (Veitchia mcdanielsii)—were grown in containers under full sun, 55% shade, or 73% shade. They were fertilized every 6 months with Osmocote Plus 15-9-12 (15N-4P-10K) at rates of 3, 6, 12, 18, 24, 30, and 36 g/pot (0.1, 0.2, 0.4, 0.6, 0.8, 1.1, and 1.3 oz/pot). For pleomele and the three palm species, optimum shoot dry weights and color ratings were similar among the three light intensities tested. However, artillery fern grown in full sun required fertilizer rates at least 50% higher for optimum shoot dry weight and color than under 55% or 73% shade. Light intensit × fertilizer rate interactions were highly significant for pilea and fishtail palm color and dry weight and sunshine palm and pleomele color.

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Timothy K. Broschat

Queen palms (Syagrus romanzoffiana) were grown in containers of sand to determine the effects of irrigation water salinity and liming rate on cation uptake by the plants. Dolomite was incorporated at rates of 0, 3, or 6 kg/m3. Within each lime rate palms were irrigated with a solution of NaCl and CaCl2 (molar ratio =5Na:1Ca) at conductivities of .25, 1, 2, 4, or 6 dS/m. Plant height and dry weight and leaf Mg were decreased with increasing irrigation water salinity, whereas leaf Ca was increased at higher salinities. Leaf Mn and Zn increased, then decreased as salinity was increased. Leaf Ca and Mg increased with increased lime, but leaf Mn and Cu were decreased by increasing the lime rate. Leaf K increased, then decreased as lime rate was increased.