Expert Co. Residential district in Naples/Ft. Myers for assistance in applying the fertilization treatments. This study was funded internally by the Davey Resource Group, a division of the Davey Tree Expert Company, Kent, Ohio.
habanero pepper that indicate an adequately fertilized protocol. Fruit yield and quality depend on fertilization among other agricultural inputs ( Epstein and Bloom, 2005 ; Raese and Drake, 1997 ). Even at low levels, fertilization often enhances yields
fertilization failure caused by self-incompatibility or cross-incompatibility, and embryo abortion ( Liang et al., 2005 ). According to the results of previous studies, the pollen of Z. jujuba Mill. ‘Zhongqiusucui’ was fertile and its pollen germination rate
, deficiencies that might merely cause twig dieback in dicots can be fatal in palms, which have only a single apical meristem and no lateral meristems. Thus, proper fertilization for palms is important for palm health and survival, as well as for aesthetics. As
Dimethyl sulfide (DMS) has been identified as the compound responsible for the characteristic aroma of cooked sweet corn (Zea mays L.) and, along with sugar and water-soluble polysaccharides, is one of the main flavor components in the kernels. Because of the close relationship between DMS and its amino acid precursor S-methylmethionine, the premise was formulated that it might be possible to improve sweet corn aroma and overall eating quality through enhanced production of DMS from increased application of N and S to the crop in the field. Studies were conducted on a Plainfield sand and a Flanagan silt loam to evaluate the effects of N and S fertilization on kernel DMS production in several commercial sh2 hybrids; in the process, the effect of N and S fertilization on various yield and yield component parameters was also determined. Hybrid was the main factor affecting kernel DMS production, although in both soils kernel DMS levels were influenced by significant interactions between hybrid and fertilizer treatments. Kernel DMS content, in response to increasing N fertilization rates, increased by an average of 85% in three of six hybrids in the Plainfield sand and by 60% in two of three hybrids in the Flanagan silt loam. The effect of S fertilization on kernel DMS production was small, with only one hybrid on the sandy soil showing a positive response (38%) to S application, and then in combination with high N rates. Irrespective of N-S fertilization regime, kernel DMS concentrations decreased at both locations by an average of ≈8.5% per day as kernel maturity increased. The results showed that kernel DMS production may be enhanced by N nutrition, independent of N fertilization effects on ear and kernel yields.
Field experiments were conducted to examine the effect of fertilization and short periods of drought on the out-of-season winter crop in prickly pear [Opuntia ficus-indica (L.) Mill.]. In addition, the winter and summer crops were compared regarding floral bud production and fruit characteristics. Under both continuous fertigation (N, P, K applied with the irrigation water) and continuous irrigation, the number of floral buds per plant was much lower in the winter than in the summer crop. Fertilization increased production of floral buds in both crops, but to a greater extent in the winter crop. The increase in floral bud production in fertilized plants was associated with an increase in NO3-N content in the cladodes. Suspension of fertigation for 4 or 8 weeks immediately after the summer harvest decreased cladode water content and delayed and reduced floral bud emergence as compared with continuous fertigation (control) or late drought (4 or 8 weeks) applied 4 weeks after the summer harvest. The plants subjected to early drought suffered from high mortality of floral buds. The fruits of the winter crop ripened in early spring, following the pattern of floral bud emergence the previous autumn. Mean fresh weight and peel: pulp ratio (w/w) were higher in fruits that ripened in the spring (winter crop) than in fruits that ripened in the summer.
Two greenhouse cucumber (Cucumis sativus) cultivars with differing fruit types [European (`Bologna') and Beit-alpha (`Sarig')] were grown during two seasons in a perlite medium in black plastic nursery containers in a passively ventilated greenhouse in northern Florida to evaluate fruiting responses to nitrogen (N) fertilization over the range of 75 to 375 mg·L–1. Fruit production, consisting mostly of fancy fruits, increased quadratically with N concentration in the nutrient solution, leveling off above 225 mg·L–1 for both cucumber cultivars. Fruit length and diameter were not affected by N concentration in the nutrient solution. Leaf N concentration, averaged over three sampling dates, increased linearly with N concentration in the nutrient solution from 46 g·kg–1 with 75 mg·L–1 N to 50 g·kg–1 with 375 mg·L–1 N. Fruit firmness decreased with increasing N concentration and there was little difference in firmness between the two cultivars. Firmness was similar across three measurement dates during the spring harvest season, but increased during the season in the fall. Fruit color responses to N concentration were dependent on the specific combination of experiment, sampling date, and cultivar. For most combinations of experiment, sampling date, and cultivar, cucumber epidermal color was greener (higher hue angle) with increased N concentration. The color was darkest (lowest L* value) and most intense (highest chroma value) with intermediate to higher N concentrations.
The relationship between fertilization and cold tolerance of plants is a confusing one. Plant nutrition involves a number of different elements, each of which may affect a plant's cold tolerance in a different manner. Most studies on fertility
Abstract
In the Feb. 1987 issue of HortScience 22:34-36, I was interested in the paper by Charles A. Mullins entitled “Effects of Nitrogen Fertilization on Production of Mechanically Harvested Snap Beans”. However, I found that two very important items of significance were not given:
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The form of N applied was not given. It would be assumed that the N fertilizer was applied at seeding, although this was not specifically indicated. The form of N can have a marked effect on the response of snap bean to applied N.
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Soil-testing information was given, but no identification of the method of extraction. Therefore, the values reported are meaningless without knowing how the test result was obtained. Such details are significant if the reader is to use the findings reported.
amounts of the micronutrient Zn ( Smith et al., 1980 ; Swietlik, 2002 ; Wood, 2007 ), and it is estimated that ≈30% of operational costs of pecan orchards is for nitrogen (N) and Zn fertilization ( Secretaria de agricultura, ganaderia, desarrollo rural