scholarly journals Response of Calceolaria ×herbeohybrida Cultivars to Substrate pH and Corresponding Leaf Tissue Nutrient Concentration Effects

HortScience ◽  
2019 ◽  
Vol 54 (12) ◽  
pp. 2163-2168
Author(s):  
W. Garrett Owen

Calceolaria (Calceolaria ×herbeohybrida) is a flowering potted greenhouse crop that often develops upper-leaf chlorosis, interveinal chlorosis, and marginal and leaf-tip necrosis (death) caused by cultural practices. The objectives of this research were to 1) determine the optimal incorporation rate of dolomitic and/or hydrated lime to increase substrate pH; 2) determine the influence of the liming material on substrate pH, plant growth, and leaf tissue nutrient concentrations; and 3) determine the optimal substrate pH to grow and maintain during calceolaria production. Sphagnum peatmoss was amended with 20% (by volume) perlite and incorporated with pulverized dolomitic carbonate limestone (DL) and/or hydrated limestone (HL) at the following concentrations: 48.1 kg·m−3 or 144.2 kg·m−3 DL, 17.6 kg·m−3 DL + 5.3 kg·m−3 HL, or 17.6 kg·m−3 DL + 10.6 kg·m−3 HL to achieve a target substrate pH of 4.5, 5.5, 6.5, and 7.5, respectively. Calceolaria ‘Orange’, ‘Orange Red Eye’, ‘Yellow’, and ‘Yellow Red Eye’ were grown in each of the prepared substrates. For all cultivars, substrate solution pH increased as limestone incorporation concentration and weeks after transplant (WAT) increased, although to different magnitudes. For example, as limestone incorporation increased from 48.1 kg·m−3 DL to 17.6 kg·m−3 DL + 10.6 kg·m−3 HL, substrate solution pH for ‘Orange’ calceolaria increased from 4.1 to 6.9 to 4.8 to 7.2 at 2 and 6 WAT, respectively. Substrate solution electrical conductivity (EC) and growth indices were not influenced by limestone incorporation, but total plant dry mass increased. Few macronutrients and most micronutrients were influenced by limestone incorporation. Leaf tissue iron concentrations for ‘Orange’, ‘Orange Red Eye’, ‘Yellow’, and ‘Yellow Red Eye’ calceolaria decreased by 146%, 91%, 71%, and 84%, respectively, when plants were grown in substrates incorporated with increasing limestone concentrations from 144.2 kg·m−3 DL to 17.6 kg·m−3 DL + 10.6 kg·m−3 HL (pH 6.5–6.9). Therefore, incorporating 144.2 kg·m−3 DL into peat-based substrates and maintaining a pH <6.5 will avoid high pH–induced Fe deficiency and prevent upper-leaf and interveinal chlorosis.

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 536
Author(s):  
James E. Altland

The pour-through procedure is a nondestructive method commonly used by horticultural crop producers and research scientists to measure chemical properties and nutrient availability in container substrates. It is a method that uses water as a displacement solution to push the substrate solution out of the bottom of the container so it can be analyzed for pH, electrical conductivity, and nutrient concentrations. The method was first introduced in the early 1980s. Since then, research has been conducted to determine factors that affect the results of the pour-through including volume, nature and timing of application of the displacement solution, container size, and substrate stratification. It has also been validated against other common methods for determining container substrate pH, EC, and nutrient concentration, most notably the saturated media extraction procedure. Over the past 40 years, the method has been proven to be simple, robust, and consistent in providing crop producers and researchers valuable information on substrate chemical properties from which management decisions and experimental inferences can be made.


2008 ◽  
Vol 26 (3) ◽  
pp. 157-163
Author(s):  
Amy L. Tillman ◽  
Stuart L. Warren ◽  
Frank A. Blazich

Abstract Rooted stem cuttings of ‘Snow White’ raphiolepis (Raphiolepis × delacourii Andre ‘Snow White’) were grown in 3.8-liter (#1) black plastic containers containing a pine bark:sand (8:1, by vol) substrate. Plants were fertilized at every irrigation, for 17 weeks, with a 4:1:2 nitrogen (N):phosphorus (P):potassium (K) nutrient solution containing N at 20, 60, 100, 140, 180, 220, or 240 mg·L−1 (ppm) supplied as ammonium nitrate (NH4NO3). Maximum top and root dry weights were achieved with N at 145 mg·L−1. Substrate solution electrical conductivity increased linearly with increasing nitrogen application rate (NAR) with maximum growth occurring at 1.28 dS·m−1, whereas substrate solution pH decreased linearly with increasing NAR with a pH of 5.3 at 145 mg·L−1. Increasing the N rate beyond 145 mg·L−1 had minimal effect on top or root dry weight. Leaf area peaked at a NAR of 171 mg·L−1 with a plateau at 524 cm2. Leaf area increased 275% as the NAR increased from 20 to 171 mg·L−1. Specific leaf area increased linearly with increasing NARs. Carbon allocation between tops and roots was unaffected by NARs from 60 to 280 mg·L−1. Root:top ratio decreased 56% between the pooled NARs (60 to 240 mg·L−1) and N at 20 mg·L−1. Leaf area ratio increased linearly with increasing NARs. Foliar mineral nutrient concentrations of N, P, and sulfur increased linearly with increasing NAR, whereas concentrations of K, calcium, magnesium, and copper responded quadratically to increasing NARs. Top growth increased from inadequate at a NAR of 60 mg·L−1 to optimum at 145 mg·L−1, whereas root growth was relatively similar over the same range. At 145 mg·L−1, mineral nutrient concentrations of the top are well within or exceed accepted levels reported, and growers can expect rapid growth of rooted cuttings.


HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 201-204 ◽  
Author(s):  
Janet F. M. Rippy ◽  
Paul V. Nelson

Measurement of substrate pH entails procurement of the substrate solution and measurement of the solution pH. Acid-base reactions are completed at the time of testing. Determination of substrate pH during development of a titration curve is more complex because it involves initially the reaction of a base with the substrate. Five factors that can influence the resulting pH values were investigated in this study and include amount of water added to substrate, method to procure substrate solution for pH determination, chemical form of base used, time allowed for acid-base reaction and the addition of CaSO4. Substrate in this study consisted of 3 sphagnum peatmoss: 1 perlite (by volume) amended with wetting agent. Dolomitic limestone (6 g·L-1 substrate) was added to substrate for the water amount and solution procurement method experiments. Except for the water amount experiment, deionized water was added by weight to achieve 95% container capacity. Dishes were incubated at 20 °C for specified times. To identify the minimal level of water necessary to ensure complete contact between base and substrate for neutralization, additions equivalent to 95%, 100%, 120%, and 150% container capacity were tested. The 95% level proved adequate. The saturated media extraction and pour-through bulk solution displacement methods for pH determination resulted in higher pH measurements in the incubated substrate than the squeeze bulk solution displacement method. This indicated that the former two methods diluted the soil solution. The squeeze method was deemed most effective. NaOH resulted in higher pH endpoints than Ca(OH)2. This was apparently due to a higher affinity of Ca2+ for peatmoss exchange sites. Since Ca2+ is the predominant cation associated with liming materials for soilless substrates, Ca(OH)2 is more appropriate for titration. From the tested incubation times of 0, 2, 4, 8, 24, 48, and 96 hours, the duration of 24 hours was found to be adequate to allow complete reaction of base with substrate acidity. The best procedure for determining pH in a substrate titration situation included a water level of 95% container capacity, Ca(OH)2 base, an incubation time of 24 hours and the squeeze solution displacement method. The additional CaSO4 was not necessary. Chemical names used: calcium sulfate (CaSO4), sodium hydroxide (NaOH), calcium hydroxide [Ca(OH)2], calcium ion (Ca2+).


1998 ◽  
Vol 16 (3) ◽  
pp. 182-188
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback

Abstract Rooted cuttings of Cotoneaster dammeri Schneid ‘Skogholm’ and seedlings of Rudbeckia fulgida Ait. ‘Goldsturm’ were potted into 3.8 liter (4 qt) containers in a pine bark:sand (8:1 by vol) substrate incorporated with 3.5 g (0.12 oz) N per container provided by one of the following five controlled-release fertilizers (CRFs): Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Two hundred ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) or 1200 ml (1.7 in) of water was applied once daily (single) or in two equal applications with a 2 hr interval between applications (cyclic). Substrate solutions were collected from containers of cotoneaster 15, 32, 45, 60, 74, 90, 105, and 119 days after initiation (DAI). Irrigation efficiency [(water applied − water leached) ÷ water applied] was determined on the same days. Cyclic application improved irrigation efficiency at 800 ml (1.1 in) and 1200 ml (1.7 in) ≈ 27% compared to a single application. Irrigation efficiencies averaged over the season were 95%, 84%, 62%, and 48% for cotoneaster and 100%, 90%, 72%, and 51% for rudbeckia at 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in) and 1200 ml (1.7 in), respectively. NH4-N and NO3-N and PO4-P concentrations in substrate solution decreased with increasing irrigation volume regardless of CRF. Substrate NH4-N concentration decreased throughout the season with most CRFs below 5 mg/liter by 90 DAI. CRFs mainly affected substrate NH4-N and NO3-N concentrations when irrigated with 200 ml (0.3 in) or 400 ml (0.6 in). Substrate NH4-N, NO3-N, and PO4-P solution concentrations were similar for all CRFs at irrigation volume of 1200 ml (1.7 in). Osmocote, Scotts, and Woodace maintained relatively constant substrate solution levels of PO4-P through 60 DAI. By 90 DAI, substrate PO4-P levels were similar regardless of irrigation volume or CRF. Substrate PO4-P concentrations were never in the recommended range of 5 to 10 mg/liter when irrigated with 800 ml (1.1 in) or 1200 ml (1.7 in) regardless of CRF. Solution pH remained in the recommended range of 5.0 to 6.0 for all irrigation volumes and CRFs throughout the entire study with the exception of Sustane.


Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 390-394 ◽  
Author(s):  
Tracy M. Sterling ◽  
Norman K. Lownds

Foliar absorption of picloram by broom snakeweed, a rangeland shrub, was investigated. Picloram uptake into leaf, axillary bud, and stem tissues was similar. In addition, picloram uptake by leaf tissue from greenhouse- and field-grown broom snakeweed did not differ. Picloram accumulated rapidly and absorption saturated between 15 min and 1 h of application; no further absorption occurred through 72 h with maximum uptake ca. 15% of applied picloram. Picloram content increased linearly with increasing external picloram concentration, implying that movement of the herbicide across the cuticle is via diffusion. Absorption was dependent on relative humidity and temperature with the greatest uptake at 94% relative humidity and 35 C, respectively. Absorption was pH dependent; picloram absorption was greatest at pH 4 and least at pH 8. In addition, picloram absorption was less at pH 3 compared to pH 4. These results provide evidence that picloram is absorbed across the cuticle via simple diffusion and absorption is dependent on environmental conditions and solution pH at and following application.


Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 10 ◽  
Author(s):  
Caroline Blanchard ◽  
Daniel E. Wells ◽  
Jeremy M. Pickens ◽  
David M. Blersch

Decoupled aquaponic systems are gaining popularity as a way to manage water quality in aquaponic systems to suit plant and fish growth independently. Aquaponic systems are known to be deficient in several plant-essential elements, which can be affected by solution pH to either increase or decrease available nutrients. To determine the effect of pH in a decoupled aquaponic system, a study was conducted using aquaculture effluent from tilapia culture tanks at four pH treatments: 5.0, 5.8, 6.5, and 7.0, used to irrigate a cucumber crop. Growth and yield parameters, nutrient content of the irrigation water, and nutrients incorporated into the plant tissue were collected over two growing seasons. pH did not have a practical effect on growth rate, internode length or yield over the two growing seasons. Availability and uptake of several nutrients were affected by pH, but there was no overarching effect that would necessitate its use in commercial systems. Nutrient concentrations in the aquaculture effluent would be considered low compared to hydroponic solutions; however, elemental analysis of leaf tissues was within the recommended ranges. Research into other nutrient sources provided by the system (i.e., solid particles carried with the irrigation water) would provide further information into the nutrient dynamics of this system.


1986 ◽  
Vol 66 (4) ◽  
pp. 971-976 ◽  
Author(s):  
J. A. CUTCLIFFE

The effects of preplant soil applications of B, Mo and dolomitic limestone on yields and leaf tissue nutrient concentrations of Rally peas were investigated at five locations with initial soil pH levels of 5.1–5.9. Experiments were conducted for two consecutive growing seasons at each location. All treatments were preplant incorporated in a 2 × 2 × 2 factorial design with five replicates. Yields of shelled peas, adjusted to tenderometer 100, varied between experiments from 1.1 to 4.8 × 103 kg ha−1 and were not generally affected by B, Mo or lime at application rates of 2.0, 0.25 and 10 000 kg ha−1, respectively. Also, the micronutrient and lime treatments had no significant effects on germination, vine length, pea/vine ratio or maturity. Leaf tissue B, Mo and Mg concentrations were increased by the applications of B, Mo and dolomitic limestone, respectively. However, leaf tissue Ca concentration was not affected by the lime treatment. The results indicate that leaf tissue concentrations of 16–74 μg g−1 B, 0.04–1.34 μg g−1 Mo and 0.23–0.55% Mg were within the sufficiency range.Key words: Peas, boron, molybdenum, dolomitic limestone, yield, leaf tissue concentration


1968 ◽  
Vol 8 (34) ◽  
pp. 606 ◽  
Author(s):  
ICR Holford

The nitrogen, phosphorus, and potassium requirements of sugar cane were studied in relation to the concentration of these elements in the leaf tissue of three varieties of sugar cane grown commercially in Fiji. Percentage yields of sugar cane in fertilizer field experiments were highly correlated with leaf nutrient levels in the control plots, provided leaf sampling was carried out during the maximum growth period of mid- January to mid-May. For each nutrient there was a marginal zone of leaf concentration below which crops always gave significant yield responses to applied nutrients and above which crops failed to respond. Marginal zones for crops sampled during mid-March to mid-May were 1.4-2.0 per cent for nitrogen, 0.13-0.21 per cent for phosphorus, and 0.9-1.5 per cent oven dry leaf for potassium. Within the deficient range of leaf nutrient concentrations there was little relationship between optimum rates of fertilizer required to correct the deficiency and leaf nutrient levels of unfertilized cane. Because of the lateness of sampling, any indication of fertilizer requirement would only be applicable to a subsequent ratoon crop.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 464f-464
Author(s):  
W.L. Berry ◽  
R.M. Wheeler ◽  
C.L. Mackowiak ◽  
G.W. Stutte ◽  
J.C. Sager

Critical levels of nutrients in leaf tissue are influenced by plant metabolism, environment, and nutrient availability. In this study, we measured the elemental concentrations in fully expanded, upper canopy potato (Solunum tuberosum cv. Norland) leaves throughout growth and development in a controlled environment. Plants were grown hydroponically (NFT) in NASA's Biomass Production Chamber using a complete nutrient solution with the electrical conductivity maintained continuously at 0.12 S m-1. Photoperiod and air and root zone temperatures were changed midseason to promote tuberization, while CO2 levels were maintained at 1000 μmol mol-1 throughout growth. During vegetative growth, leaf nutrient concentrations remained relatively constant, except for a decline in Ca. During tuber enlargement and plant maturation, overall nutrient uptake decreased. Concentrations of the less mobile nutrients such as Ca, Mg, and B increased in the leaf tissue during mature growth, but somewhat surprisingly, highly mobile K also increased. Leaf concentrations of P, Zn, and Cu decreased during maturation.


HortScience ◽  
2014 ◽  
Vol 49 (11) ◽  
pp. 1437-1443 ◽  
Author(s):  
Alexander X. Niemiera ◽  
Linda L. Taylor ◽  
Jacob H. Shreckhise

To reduce the carbon-to-nitrogen (C:N) ratio, pine tree substrate (PTS) and other wood-based substrates can be precharged with urea so that growers do not have to add extra nitrogen (N) during crop production to compensate for immobilization. However, the impact of urea hydrolysis from this addition on the substrate solution has not been documented for wood-based substrates. The objectives of these experiments were to determine how urea hydrolysis in PTS impacts substrate solution and how hydrolysis is affected by urea and lime rates. In Expt. 1, 16-month-old pine chips (from loblolly pine trees, Pinus taeda L.) were milled to make PTS and PTS was amended with 0 or 1.0 kg·m−3 dolomitic limestone in factorial combination with urea-N rates of 0, 0.5, 1.0, 1.5, or 2.0 mg·g−1 dry weight. Urea hydrolysis was quantified by the detection of NH4-N in the substrate solution at 0, 48, 96, and 144 hours after urea addition. Substrate pH and electrical conductivity (EC) values were also measured. In Expt. 2, non-limed PTS was treated with the same urea rates as described; NH4-N and pH were measured at 24 and 48 hours after urea addition. Substrate solutions were incubated with jackbean urease to determine the remaining urea-N amount after 144 hours in Expt. 1 and after 24 and 48 hours in Expt. 2. In Expt. 1, NH4-N increased from 0 to 48 hours for the 0 and 1.0-kg·m−3 lime treatments and for all urea-N rates (except for the 0 rate); NH4-N did not increase thereafter. As urea-N rate increased, the amount of NH4-N increased and more N was detected for the limed PTS than in the non-limed PTS. Initial substrate pH values for the 0 and 1.0-kg·m−3 lime treatments were 4.5 and 5.6, respectively, and peaked 48 hours after urea application; pH values were higher in the limed PTS than for the non-limed PTS. At the highest urea-N rate and after 48 hours (Expt. 1), the PTS pH value increased 3.1 units to 7.6 for the non-limed PTS and the value increased 2.3 units to 7.9 for limed PTS. In Expt. 2 the increase in PTS pH values was approximately half of the Expt. 1 pH increases. Samples treated with urease derived from jackbean had less than 2% of the initial urea amount after 144 hours in Expt. 1 and after 48 hours in Expt. 2. However, less than 13% of the total amount of urea-N added to PTS was detected as NH4-N in the non-limed treatment after 144 hours in Expt. 1 (for all urea rates); detected amounts for the 1.0-kg·m−3 lime treatment ranged from 15.5% to 18.3%. Five percent or less of the total amount of urea-N added to PTS was detected as NH4-N in non-limed PTS after 48 hours in Expt. 2 (for all urea rates). The large amount of unrecovered NH4-N is likely explained by microbial N consumption. Using pH increase as an indication of urea hydrolysis, we found that an initial pH of 4.5 or higher (Expt. 1) resulted in twice the urea hydrolysis as an initial pH of 4.2 (Expt. 2). Initial substrate pH had a major impact on the amount of pH increase and substrate pH status and our findings suggest that the urea precharge rate should be based on the initial pH of the substrate.


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