Tomato (Lycopersicon esculentum Mill.) was grown with drip irrigation on an Arredondo fine sand and on an Orangeburg fine sandy loam to evaluate the effect of N and K time of application on petiole sap, leaf-N and -K concentrations, fruit yield, and to determine N and K sufficiency ranges in leaf tissue. On the sandy soil, N—K at 196-112 kg·ha-1 were applied 0%, 40%, or 100% preplant with the remainder applied in 6 or 12 equal or in variable applications in 12 weeks. With the variable application rate, most nutrients were applied between weeks 5 and 10 after transplanting. On the sandy loam soil that tested high in K, only N (196 kg·ha-1) was applied as above. Petiole sap K concentration declined during the season, but was not greatly affected by treatment. Petiole NO3-N concentrations decreased during the season from 1100 to 200 mg·L-1, and the decrease was greater with preplant N treatments. On the sandy soil, marketable fruit yields were lowest with 100% preplant, intermediate with 100% drip applied (no preplant N), and highest with 40% preplant and 60% drip applied. With 100% drip applied, yields were higher with 12 even applications than with either six even weekly applications or with 12 variable N and K applications. With 40% preplant, timing of application had little effect on yield. On the sandy loam soil in 1993, yields were highest with 100% preplant, intermediate with 40% preplant and 60% drip applied, and lowest with all N drip applied. In 1994 when excessive rains occurred, yields were similar with all preplant and with split N applications. Petiole N concentration was correlated with tomato yield, especially at 10 weeks after transplanting. The best correlation between sap-N and total yields occurred between 4 and 6 weeks at Gainesville and between 4 and 10 weeks at Quincy.
Salvadore J. Locascio, George J. Hochmuth, Fred M. Rhoads, Steve M. Olson, Alan G. Smajstrla, and Ed A. Hanlon
Bernadine C. Strik and David R. Bryla
(which depend on caneberry type and planting age), with adjustments made to N and other nutrients as needed, based on periodic soil nutrient analysis and annual leaf tissue analysis. Primocane leaf nutrient status, as compared with sufficiency levels
Raul I. Cabrera and Pedro Perdomo
The performance of modern greenhouse-grown roses under intensive nutrient and water management practices questions their traditional classification as a salt-sensitive species, and emphasizes the need to reassess their salinity tolerance. Container-grown `Bridal Pink' roses (on R. manetti rootstock) in a peat moss-based growing medium were irrigated, using moderate leaching fractions (25% targeted, 37.5% actual), with complete nutrient solutions supplemented with NaCl at 0, 5, and 10 mm. These salt concentrations affected the electrical conductivity (EC) and Cl concentrations measured in the leachates, but had no significant effects on flower yield and quality over four growth and flowering flushes (§29 weeks). Cumulative yields over this period increased an average of §13% per leachate EC unit. Thereafter, the applied NaCl concentrations were increased 3-fold to 0, 15, and 30 mm and the plants continued to be evaluated for another four flowering flushes. No significant differences in cut-flower yield and quality were observed among salt treatments despite further increases in leachate EC and Na and Cl concentrations. Symptoms of salt injury were visually observed during the last three flowering cycles, and most heavily on the oldest foliage of plants receiving the highest salt concentration (30 mm), but not on the foliage of harvested shoots. The concentration of most nutrients in leaf tissue was not significantly affected by any of the treatments over the course of the experiment. Leaf Na concentrations were not affected by NaCl applications, averaging 42 mg·kg-1 across treatments. Conversely, leaf Cl concentrations increased significantly and cumulatively over time with salt additions, and ranged from 1.0 to 17.5 g·kg-1 (0.1 to 1.75%). Regression analyses revealed that average relative dry weight yields increased with leaf Cl concentrations up to 4.0 g·kg-1 (0.40%), but were depressed at higher concentrations.
Ivan dos Santos Pereira, Luciano Picolotto, Michél Aldrighi Gonçalves, Gerson Kleinick Vignolo, and Luis Eduardo Corrêa Antunes
The objective of this study was to evaluate the floricane leaf nutrient content, vegetative growth, and yield of two blackberry (Rubus spp.) cultivars (Tupy and Xavante), in response to rate of potassium (K) fertilization (0.0, 2.1, 4.2, 6.2, or 8.3 g/plant of K). The research was conducted in a region of low chill (342 chill hours) in southern Brazil (lat. 31°40′ 46.98 S, long. 52°26′ 4.36 W), and soil with pH 5.9, organic matter (OM) 1.1% and K 58.0 g·m−3. In 2009, only calcium (Ca) and magnesium (Mg) leaf concentration were affected by K application, and leaf K level was considered below normal for blackberry in Brazil. In 2010 and 2011, leaf K of blackberry in Brazil increased linearly in both cultivars with an increase in applied K. However, leaf K of blackberry in Brazil only reached its recommended levels for optimal growth in 2010 with the application of 2.1 and 8.3 g/plant of K for ‘Tupy’ and ‘Xavante’, respectively. In 2011, an antagonistic relationship was seen between leaf nitrogen (N)/K and K/Ca and K/Mg ratios with increasing K rates, where increasing K rates were accompanied by a linear decrease in the N/K ratio and a linear increase in the K/Ca and K/Mg ratios. Micronutrients evaluated showed no significant response to applied rates of K. A decrease in floricane leaf concentration of phosphorus (P), iron (Fe), manganese (Mn), and zinc (Zn) was also observed over years of the study. Potassium fertilization rates influenced the vegetative growth of blackberries. ‘Tupy’ showed increased cane density and pruning weights with increased rates of K application up to 8.3 g/plant, whereas cane density was optimized in ‘Xavante’ at 4.2 g/plant. The fruit yield of ‘Tupy’ and ‘Xavante’ increased linearly with K application per plant in all three years, indicating that K fertilization may be limiting the yield potential of these cultivars. These results suggest that the current K fertilizer recommendations may need to be increased for optimal production in Brazil.
Suping Zhou, Roger J. Sauve, and Abdulah Abdulah
Complementary Deoxyribonucleic Acid (cDNA) differential display and reverse Northern dot blot were used to identify genes in Pachysandra terminalis Sieb. & Zucc., a cold-tolerant plant, that are regulated by low temperatures. Rooted cuttings were obtained from stock plants that had been maintained in a greenhouse at 24 °C. These cuttings were subjected to the following cold treatments: 2 weeks at 12 °C, 48 hours at 4 °C, 48 hours at 0 °C, and 4 hours at –1 °C. Following leaf tissue analysis of treated and control plants, some stress-related genes and many novel genes were identified. Northern blot hybridization demonstrated that all novel genes were regulated by the cold treatments.
C.A. Sanchez, M. Lockhart, and P.S. Porter
Five field experiments were conducted from 1986 through 1988 to evaluate the response of radish (Raphanus sativus L.) to rate and source of P (triple superphosphate and phosphoric acid) and to rate of K (KC1) on Histosols. Marketable radish root yields increased with P fertilization when the soil tested <13 mg P/dm3 using a test for water-soluble P. No significant differences were due to P source. Results of leaf tissue analysis suggested that the critical concentration of P in radish leaves was 0.45%. Radish did not respond to K fertilization in any of the five experiments, even though preliminary soil-test K levels ranged from 20 to 102 K/dm3. Histosols used for crop production in Florida rarely test below 20 mg K/dm3; thus, radish rarely would require supplementary K fertilization for optimal yield.
William H. Olson, Kay Uriu, and Jim Pearson
Initial leaf tissue-analysis indicated that the degree of distortion and dieback in a young walnut orchard was correlated with decreasing amounts of Cu in the leaf. Complete correction of Cu deficiency was obtained for two years when high rates of Kocide 101 were used or when low rates were applied repeatedly each year. Soil treatments gave partial correction; soil injected treatments showed continued improvement over time. Tissue analysis for Cu correlated well with the degree of distortion and dieback in the trees. Critical Cu levels in the walnut kernel were 4 ppm and 3 ppm in the leaf. Kernel and leaf tissue levels were highly correlated. Shriveling of the kernels was the main nut quality symptom associated with Cu deficiency. High rates of foliar or a combination of foliar and soil treatments may give the best results in young trees. Once trees are in production, the standard yearly Cu program for walnut blight control should provide adequate Cu deficiency correction.
Edward W. Bush, James N. McCrimmon, and Allen D. Owings
Four warm-season grass species [common carpetgrass (Axonopus affinis Chase), common bermudagrass (Cynodon dactylon [L.] Pers.), St. Augustinegrass (Stenophrum secondatum Walt. Kuntze.), and zoysiagrass (Zoysia japonica Steud.)] were established in containers filled with an Olivia silt loam soil for 12 weeks. Grasses were maintained weekly at 5 cm prior to the start of the experiment. Water stress treatments consisted of a control (field capacity), waterlogged, and flooded treatments. Waterlogging and flood treatments were imposed for a period of 90 days. The effects of water stress was dependent on grass species. Bermudagrass vegetative growth and turf quality were significantly reduced when flooded. Carpetgrass, St. Augustingrass, and zoysiagrass quality and vegetative growth were also reduced by flooding. St. Augustinegrass and zoysiagrass root dry weight was significantly decreased. Zoysiagrass plants did not survive 90 days of flooding. Leaf tissue analysis for common carpetgrass, common bermudagrass, St. Augustinegrass, and zoysiagrass indicated that plants subjected to waterlogging and flooding had significantly elevated Zn concentrations.
K. Cushman, R. Snyder, T. Horgan, and A. Bufogle
Five fertilizer treatments, three of which included swine effluent alone or in combination with commercial fertilizers, were evaluated for plasticulture production of vegetables. Effluent and/or soluble fertilizers were delivered through drip irrigation tubing to their respective treatments. Four experiments were conducted at two locations: 1) spring tomatoes followed by pumpkin at Verona, Miss., 2) spring tomatoes followed by zucchini at Pontotoc, Miss., 3) fall tomato at Verona, and 4) fall tomato at Pontotoc. In all four experiments, representing six crops, yields from treatments receiving swine effluent were equal to or greater than yields from treatments receiving preplant fertilizers and/or commercially available soluble fertilizers. There were also no significant differences among treatments in relative number of marketable fruit. Leaf tissue analysis of the tomato crops showed no significant differences among treatments in N content. For some experiments, there were significant differences for other elements. These results showed that swine effluent was an effective nutrient source for plasticulture production of vegetable crops when compared to preplant and soluble fertilizers. These results also showed that the alkaline pH (about 7.8) and high level of ammonium nitrogen of swine effluent (>95 % of N content) did not adversely affect vegetable yield or marketability.
Rooted cuttings of Rhododedron catawbiense `Roseum Elegans' were potted on February 27, 1992, in 1 liter pots containing sphagnum peat moss:composted pine bark:sand:pinewood peelings:coal bottom ash mixed at ratios of 15:70:15:0:0, 15:70:0:0:15, 15:35:15:35:0, 15:35:0:35:15, 15:0:15:70:0 or 15:0:0:70:15 percent volume. Irrigation and fertilization frequencies were recorded from March 18-September 18, 1992. Moisture retention data showed that the high pinewood peeling mixes retained less moisture but that coal bottom ash improved moisture retention when substituted for sand in all mixes. The highest pinewood peeling:ash medium required less irrigation than the other mixes but a higher frequency of acid fertilization. The highest pine bark:sand medium required more. neutral fertilization than the other mixes. Numbers of new shoots per plant in the 15:35:15:35:0, 15:0:15:70:0 and 15:0:0:70:15 media were lower than those in the high pine bark:ash mix. Plant heights were lower in the 15:0:15:70:0 mix. Flower buds per plant were higher in the 15:35:15:35:0 medium than in the 15:70:15:0:0, 15:0:15:70:0 or the 15:0:0:70:15 plants. Leaf tissue analysis showed K and Cu to be at deficiency levels in all plants. Boron was higher in all plants grown in ash containing media. Zinc was low in plants grown in high pinewood peelings media.