Search Results

You are looking at 81 - 90 of 8,971 items for :

Clear All
Free access

Timothy K. Broschat

All leaves from 10 replicate Cocos nucifera L. `Malayan Dwarf' (COC) and Phoenix canariensis Chabaud (CID) trees were sampled for leaf nutrient analysis. In addition, the leaflets of the youngest fully expanded leaves and the third oldest leaves were divided into five groups along the primary leaf axis and these leaflets were then cut into thirds to determine nutrient distribution patterns within leaves and leaflets. Nutrient remobilization rates were calculated for N, P, K, Mg, and Mn. Results showed that N, P, and K were highly mobile within and between leaves of both species of palms. Up to 31% of the N, 66% of the K, and 37% of the total P in the oldest leaves were ultimately remobilized to newer leaves within the palm. Magnesium remobilization rates averaged ≈71% for CID but only ≈10% for COC. The middle-aged leaves appeared to be the primary sink for Mg in COC, rather than the youngest leaves as in CID. Manganese was also quite mobile in both species, with up to 44% of the total Mn remobilized in CID. Samples consisting of recently matured leaves were determined to be the most appropriate for Ca, Fe, Mg (COC only), and Zn, but oldest leaves are more suitable for N, P, K, and Mn analysis.

Free access

Thomas H. Yeager, Joseph K. von Merveldt and Claudia A. Larsen

nutrient concentrations (NO 3 -N, P, and K) were determined according to standard procedures ( Analytical Research Laboratory, 2008 ) for Blocks 1 to 4. At experiment termination, visual appearances were observed and roots were washed of substrate and stems

Free access

Hala G. Zahreddine, Daniel K. Struve and Salma N. Talhouk

two true leaves, they were fertilized once per week with 100 mg·L −1 N of 20N–8.3P–4.6K (20-10-10, Peters water-soluble fertilizer; O.M. Scotts Company, Marysville, OH). Plants were overwintered (from November to May) in a minimum heat (minimum

Free access

Sanjit K. Deb, Parmodh Sharma, Manoj K. Shukla, Theodore W. Sammis and Jamshid Ashigh

FGSC (considered as a control) and three higher salinity treatment levels (EC IRR = 3.5, 5.5, and 7.5 dS·m −1 ). Concentrations of Na + , Ca 2+ , Mg 2+ , K + , NO 3 -N, and Cl – in the control irrigation water were 56.6 ± 0.5, 75.3 ± 0.7, 12.8 ± 0

Free access

Raúl Medina-Torres, Samuel Salazar-García and José Roberto Gómez-Aguilar

Nance [Byrsonima crassifolia (L.) HBK.] is a tropical fruit cultivated along the coastal areas of Mexico. Nance consumption has increased due to its versatility, as it can be used as fresh fruit, refreshments, and alcoholic beverages and also for preparing fruit rolls, bottled drinks, jellies, syrup, ice cream, and cakes. However, the broad variation in fruit quality parameters, like juice acidity, total soluble solids, skin color, and size, seems to limit its use. Since fruit quality can be influenced by the parameter used, multivariate canonical discriminant analysis (CDA) was used to discriminate among nance selections. The objective of this study was to find the best quality indices using physical and chemical fruit characteristics from eight nance selections cultivated in the state of Nayarit, Mexico. Six physical and five chemical variables of fruit quality were studied to determine the relative contribution of each variable to the discrimination between nance selections. Two canonical discriminant functions (CDF1 and CDF2) explained >80% of the accumulated variation among nance selections. The total soluble solids (TSS) to titratable acidity (TA) ratio was dominant on the CDF1 (standardized canonical coefficient = 2.46), therefore, this ratio could be used as the best quality index to select nance fruit. The following TSS to TA values are proposed to classify the nance selections studied: a) 5.1 to 8 as sour fruit (Sour-small and Purple selections), b) 8.1 to 10 as sweet-sour fruit (Conical, Improved, Sweet-sour-1, Sweet-sour-2, and Sweet-sour-3 selections), and c) >10 as sweet fruit (Sangunga selection).

Free access

William H. Olson

Six years of previous research in a 12-year-old English walnut orchard, with a history of potassium deficiency, created a large number of trees with different potassium status. This provided the opportunity to study the long-term effects different potassium status has on English walnut trees growth, productivity, and nut quality. Walnut trees with a history of potassium deficiency, adequacy or luxury continued in this mode during this evaluation. Positive correlations existed between July leaf potassium levels and tree trunk sectional area (TCSA), visual potassium status, percent husk potassium, yield per tree, and tree yield per TCSA. These positive correlations suggest July leaf potassium levels of 1.4% to 1.5% as being adequate. This is higher than the 1.2% leaf potassium level currently recommended as being adequate for a July sample. Poor or no correlations existed between July leaf potassium levels and percent shell potassium, shell weight, shell breaking force, percent broken shell, nut size, nut weight, percent kernel potassium, percent light-colored kernels, percent edible kernel, percent kernel yield, or percent shriveled kernel. Trees with leaf potassium levels at or above 1.5% July leaf potassium produced 80 pounds per tree more yield than trees with leaf potassium levels at or below 1.0% July leaf potassium levels. These data indicate that good tree potassium status influences tree size and tree productivity. Also the walnut husk is an important sink for the accumulation of potassium. Currently recommended adequate potassium levels for walnut appear to be lower than what this study indicates.

Full access

Timothy K. Broschat and Kimberly K. Moore

In two experiments, chinese hibiscus (Hibiscus rosa-sinensis), bamboo palm (Chamaedorea seifrizii), areca palm (Dypsis lutescens), fishtail palm (Caryota mitis), macarthur palm (Ptychosperma macarthurii), shooting star (Pseuderanthemum laxiflorum), downy jasmine (Jasminum multiflorum), plumbago (Plumbago auriculata), alexandra palm (Archontophoenix alexandrae), and foxtail palm (Wodyetia bifurcata) were transplanted into 6.2-L (2-gal) containers. They were fertilized with Osmocote Plus 15N-3.9P-10K (12-to14-month formulation) (Expt. 1) or Nutricote Total 18N-2.6P-6.7K (type 360) (Expt. 2) applied by either top dressing, substrate incorporation, or layering the fertilizer just below the transplanted root ball. Shoot dry weight, plant color, root dry weights in the upper and lower halves of the root ball, and weed shoot dry weight were determined when each species reached marketable size. Optimal fertilizer placement method varied among the species tested. With the exception of areca palm, none of the species tested grew best with incorporated fertilizer. Root dry weights in the lower half of the root ball for chinese hibiscus, bamboo palm, and downy jasmine were greatest when the fertilizer was layered and root dry weights in the upper half of the root ball were greatest for top-dressed chinese hibiscus. Weed growth was lower in pots receiving layered fertilizer for four of the six palm species tested.

Open access

Bryan J. Peterson, Gregory J.R. Melcher, Ailish K. Scott, Rebecca A. Tkacs and Andrew J. Chase

date, substrate composition, wounding, and the concentration of applied potassium salt of K-IBA on rooting percentage and metrics of root system quality. Materials and methods Plant materials . We identified native populations of sweetgale, rhodora, and

Full access

Timothy K. Broschat

Release rates at 21 °C were determined in sand columns for 12 commercially available soluble and controlled-release Mg fertilizers. Lutz Mg spikes, K2SO4, MgSO4, MgSO4·H2O, and MgSO4·7H2O released their Mg within 2 to 3 weeks. Within the first 6 weeks, MgO·MgSO4 released its soluble Mg fraction, but little release occurred thereafter. Dolomite and MgO released <5% of their Mg over 2 years while MagAmp released <20% of its Mg. Florikan 1N-0P-26K-4Mg types 100 and 180 exhibited typical controlled-release fertilizer characteristics, with most of their Mg release occurring during the first 15 weeks.