-pollination, followed by controlled self-pollination (11.66%) and by open pollination (0.27%). Pollination type influenced the fruit fertilization rate and the number of seeds ( Supplemental Table 4 ), with significant difference between the pollinations ( P ≤ 0
Viviane de Oliveira Souza, Margarete Magalhães Souza, Alex-Alan Furtado de Almeida, Joedson Pinto Barroso, Alexandre Pio Viana, and Cláusio Antônio Ferreira de Melo
C.A. Mullins, R.A. Straw, B. Pitt Jr., D.O. Onks, M.D. Mullen, J. Reynolds, and M. Kirchner
`Silver Queen', `Incredible', and `Challenger' sweet corn (Zea mays L.) cultivars were evaluated at different nitrogen (N) fertilization rates at Springfield, Tenn., in 1993, 1994, and 1995. `Incredible' was more productive than `Silver Queen' and `Challenger'. Of the three cultivars, `Silver Queen' had the tallest plants, longest ears, and most attractive ears. Nitrogen fertilization rates were 0, 50, 100, and 150 (100 lb/acre at planting and 50 lb/acre sidedressed) lb/acre (0,56, 112, and 168 kg·ha-1). The 100 lb/acre rate of N applied at planting appeared to be sufficient for producing sweet corn in soils with an annual cropping frequency. Height of plants and ear diameters were larger at the higher fertilization rates, but differences among treatments were not great and were usually not significant. The cultivars of different genetic types did not differ in response to N fertilization rates. Cultivar × year interactions were significant for most factors evaluated, but most other interactions were not significant.
Laura Jalpa, Rao S. Mylavarapu, George J. Hochmuth, Alan L. Wright, and Edzard van Santen
produced on sandy soils, using NUE and APR as indices of evaluating efficiency. Thus, our objectives were to determine the effect of N fertilization rate on the responses of tomato, including 1) N accumulation in plant tissues, 2) crop N requirement, and 3
Richard Smith, Michael Cahn, Timothy Hartz, Patricia Love, and Barry Farrara
been recognized as a nitrate leaching hazard ( Bakker et al., 2009b ; Congreves and Van Eerd, 2015 ; Everaarts, 2000 ). Yield-maximizing N fertilization rates for cole crops have been reported to range from <150 to >400 kg·ha −1 ( Bakker et al., 2009
Timothy K. Broschat and Kimberly A. Klock-Moore
Areca palms [Dypsis lutescens (H. Wendl.) Beentje & J. Dransf.], spathiphyllums (Spathiphyllum Schott. `Figaro'), ixoras (Ixora L. `Nora Grant'), tomatoes (Lycopersicon esculentum Mill. `Floramerica'), marigolds (Tagetes erecta L. `Inca Gold'), bell peppers (Capsicum annuum L. `Better Bell'), and pentas [Pentas lanceolata (Forssk.) Deflers. `Cranberry'] were grown in a pine bark-based potting substrate and were fertilized weekly with 0, 8, 16, 32, or 64 mg (1.0 oz = 28,350 mg) of P per pot. Shoot, and to a much lesser extent, root dry weight, increased for all species as weekly P fertilization rate was increased from 0 to 8 mg/pot. As P fertilization was increased from 8 to 64 mg/pot, neither roots nor shoots of most species showed any additional growth in response to increased P. Root to shoot ratio decreased sharply as P fertilization rate was increased from 0 to 8 mg/pot, but remained relatively constant in response to further increases in P fertilization rate.
Craig A. Storlie, Philip E. Neary, and James W. Paterson
The effects of fertilizer rates and application frequency on drip-irrigated bell peppers (Capsicum annuum L.) were evaluated at two sites in 1992 and one site in 1993 in southern New Jersey. Yield and fruit quality were greatest with 158N-69P-131K lb/acre at the site with a sandy loam soil. Yield and fruit quality responded to additional fertilizer at sites with loamy sand soils. Average marketable fruit weight increased with increasing fertilization rate at one of the two loamy sand sites. The incidence of sun scald decreased with increasing fertilization rate. Increasing the frequency of drip-applied fertilizer from 11 to 22 days did not affect yield or fruit quality in either year when the same amount of fertilizer was applied. These results show that maximizing the yield of bell peppers grown on loamy sand soils in New Jersey may require higher fertilization rates than previously recommended.
Gitta Shurberg, Amy L. Shober, Christine Wiese, Geoffrey Denny, Gary W. Knox, Kimberly A. Moore, and Mihai C. Giurcanu
agrees with our findings that while size may increase for some species at higher fertilization rates, increasing the fertilizer rate did not result in increased plant quality ( Chen et al., 2011 ). Chen et al. (2011) reported an increase in SI for some
Brian E. Whipker, Shravan Dasoju, Michael S. Dosmann, and Jeffery K. Iles
Double impatiens (Impatiens wallerana Hook.) `Blackberry Ice' (variegated-leaf) and `Purple Magic' (green-leaf) were grown on flood benches and irrigated with 50, 100, 200, or 300 mg·L-1 (ppm) N to study the effect of fertility on growth and development. Electrical conductivity (EC) levels at week 9 were similar for both cultivars at each fertilizer rate, except for the 100 mg·L-1 N where EC levels of `Blackberry Ice' were more than double those of `Purple Magic'. This indicated that the nutrient demands were less for `Blackberry Ice' and fertilization rates lower than 100 mg·L-1 N would be required. After nine weeks, plants grown with 100 mg·L-1 N had a 22% larger plant diameter than plants grown with either 50 or 200 mg·L-1 N. Fertilization rates of 50 mg·L-1 N resulted in plants which were covered with a higher percentage of blooms per unit of leaf area, but the plants were smaller. Plant tissue dry weight (leaf, bud, stem, and total) increased to the highest level at 100 mg·L-1 N, then decreased with further increases in fertilization rate. For maximum shoot growth with flood irrigation, growers should apply 100 mg·L-1 N when growing `Purple Magic' double impatiens and a fertilization rate between 50 and 100 mg·L-1 N for `Blackberry Ice'.
Sergio Lopez-Cuevas and Terence Robinson
A factorial field experiment was conducted at the New York State Agricultural Experimental Station in Geneva, N.Y., during 2004 and 2005 with `Honeycrisp' apple trees on M.9 rootstock. The main plot factors were three levels of applied nitrogen (0 kg/ha, 50 k/ha, and 100 k/ha); three levels of applied K2O (0 k/ha, 100 kg/ha, and 200 kg/ha); ± foliar nutrient sprays containing N, B, Zn, and Mg, ± foliar sprays of CaCl2 and ± trickle irrigation. The subplot factor was cropload (3, 6, 9, 12, and 15 fruits/cm2 TCA). Trees receiving irrigation or potassium had higher yields and the effect was greater as cropload was increased. There was no effect of nitrogen fertilization, foliar Ca, and foliar N, B, Zn, and Mg on yield. Irrigation and increased potassium fertilization rate reduced fruit soluble solids at harvest. Foliar calcium applications, foliar N, B, Zn, and Mg applications, and nitrogen fertilization rate did not affect fruit soluble solids at harvest. No treatment factor had an effect on fruit firmness at harvest, but, after 4 months on cold storage, fruits from irrigated trees had greater firmness. Bitter pit incidence was lower on apples from trees that did not receive irrigation compared to irrigated trees. The difference was constant under all cropload levels. Foliar calcium applications, foliar N, B, Zn, and Mg applications, nitrogen fertilization rate and potassium fertilization rate did not affect bitter pit incidence.
Javiera Morales, Ximena Besoain, Italo F. Cuneo, Alejandra Larach, Laureano Alvarado, Alejandro Cáceres-Mella, and Sebastian Saa
that specific N fertilization rates (using NH 4 NO 3 as the N source) can minimize P. cinnamomi damage in walnut saplings. We found that 70-ppm N fertilization reduced disease severity in roots and canopy while maximizing the positive effect of N in