Abstract
The objective was to quantify the effect of substrate pH and micronutrient concentration on growth and pigment content for two floricultural crop species, Petunia × hybrida `Priscilla' and Impatiens wallerana `Rosebud Purple Magic'. A 70% peat: 30% perlite medium was amended with dolomitic hydrated lime to achieve five substrate pH's ranging from pH 4.4 to 7.0. Plants were grown in 10-cm-diameter pots in a greenhouse for 4 weeks, and irrigated with a fertilizer containing (in mg·L -1 ) 210N-31P-235K-200Ca-49Mg. Micronutrients were applied using an EDTA (ethylenedinitrilotetraacetic acid) chelated micronutrient blend (C111), at 1×, 2×, and 4× concentrations (in mg·L -1 ) of 0.50Fe-0.25Mn-0.025Zn-0.04Cu-0.075B-0.01Mo. Petunia shoot dry mass and stem caliper decreased as substrate pH increased, whereas leaf length and width remained unchanged. The highest level of C111 resulted in higher dry mass and smaller leaf area compared with other C111 levels. Overall, substrate pH and C111 had little effect on plant size or mass for impatiens. For both species, increasing substrate pH above 5.3 resulted in a decline in chlorophyll, carotenoids, and the SPAD chlorophyll index (measured with a Minolta-502 SPAD meter) compared with the lowest three pH levels. Chlorosis was observed at pH 7 after 2 weeks of growth. Increasing C111 concentration had no effect on pigment content below pH 5.3, but increased pigment content at higher pH levels. The SPAD index was highly correlated with chlorophyll content. This research emphasizes that an acceptable range in substrate pH can vary depending on fertilizer practices, with higher micronutrient concentration compensating for lower solubility at high substrate pH.
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Claims 11
Claim · model-written summary
Petunia shoot dry mass and stem caliper decreased as substrate pH increased.
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PetuniaOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
_flowers_in_Westgate_Gardens%2C_Canterbury.jpg?width=500)
Verbatim
e0“Petunia shoot dry mass and stem caliper decreased as substrate pH increased”
Claim · model-written summary
Petunia leaf length and width remained unchanged with pH.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Petunia shoot dry mass and stem caliper decreased as substrate pH increased, whereas leaf length and width remained unchanged”
Claim · model-written summary
Highest C111 increased petunia dry mass.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest level of C111 resulted in higher dry mass and smaller leaf area compared with other C111 levels”
t0“Petunia”
Claim · model-written summary
Highest C111 reduced petunia leaf area.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest level of C111 resulted in higher dry mass and smaller leaf area compared with other C111 levels”
t0“Petunia”
Claim · model-written summary
Substrate pH and C111 had little effect on impatiens size and mass.
ImpatiensOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Overall, substrate pH and C111 had little effect on plant size or mass for impatiens”
Claim · model-written summary
Above pH 5.3, chlorophyll, carotenoids, and SPAD index declined in petunia and impatiens.
- Treatment
- substrate pH above 5.3e0
- Outcome
- chlorophyll, carotenoids, and the SPAD chlorophyll indexe0
- Direction
- declinee0
- Comparator
- lowest three pH levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For both species, increasing substrate pH above 5.3 resulted in a decline in chlorophyll, carotenoids, and the SPAD chlorophyll index (measured with a Minolta-502 SPAD meter) compared with the lowest three pH levels”
t0“Impatiens and Petunia”
Claim · model-written summary
Chlorosis appeared at pH 7 after two weeks.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chlorosis was observed at pH 7 after 2 weeks of growth”
t0“Impatiens and Petunia”
Claim · model-written summary
Increasing C111 had no pigment effect below pH 5.3.
- Treatment
- Increasing C111 concentratione0
- Outcome
- pigment contente0
- Direction
- no effecte0
- Qualifier
- below pH 5.3e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing C111 concentration had no effect on pigment content below pH 5.3”
t0“Impatiens and Petunia”
Claim · model-written summary
Increasing C111 increased pigment content at higher pH.
- Treatment
- Increasing C111 concentratione1
- Outcome
- pigment contente0
- Direction
- increasede0
- Qualifier
- at higher pH levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but increased pigment content at higher pH levels”
t0“Impatiens and Petunia”
e1“Increasing C111 concentration had no effect on pigment content below pH 5.3”
Claim · model-written summary
SPAD index was highly correlated with chlorophyll content.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The SPAD index was highly correlated with chlorophyll content”
t0“Impatiens and Petunia”
Claim · model-written summary
Higher micronutrient concentration compensates for lower solubility at high substrate pH.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher micronutrient concentration compensating for lower solubility at high substrate pH”
t0“Impatiens and Petunia”
The same questions in other papers
growing medium · physiology: pigments · Petunia (petunia)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
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2 papers more in this group
See all 6 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.