Job offersmore »
- Purchasing Specialist Exoten - Netherlands
- Intercompany Key Account Manager Exoten - Netherlands
- Buitendienst Medewerker - Oost Nederland
- Managing Grower - Australia
- Senior Grower - Talbotville, Ontario, Canada
- Operations Manager - Fresh Produce
- Senior Account Manager Retail - Netherlands
- Supply Allocation and Inventory Manager - Fresh Produce, Italy
- Senior Grower - Katunga, Australia
- Key Account Manager - Netherlands
Last commentsmore »
- Will sea freight be an alternative to Latin American air freight? (28)
- India: Government gives 50% subsidy on a poly house (964)
- NL: A sustainable packaging for a grateful plant (1)
- "I tested my growing media, now what?" (1)
- "Scoop Scabiosa offers more texture, more color, more inspiration" (1)
- Photo Report: First edition HortEx Vietnam (1)
- Danish greens grower expands with first own bred peperomias (2)
- UK: What's in season at the New Covent Garden Flower Market (5)
- Women's Day: "Russian market is growing up" (3)
- Export stop Australia as of March 1 2018 (2)
Top 5 - yesterday
Top 5 - last week
Top 5 - last month
Exchange ratesmore »
Acidic and basic effects of floriculture species in peat-based substrateFloriculture species differ in their effect on substrate-pH and the resulting substrate micronutrient availability in container production. The objective of a new study was to quantify effects of floriculture plant species on substrate-pH.
In a growth chamber factorial experiment, 15 floriculture species were grown in 70%:30% by volume peat:perlite substrate and fertilized with nutrient solutions containing 100 mg·L−1 N and NH4+-N:NO3−-N nitrogen ratios of 0:100, 20:80, or 40:60. The relationship between substrate-pH and milliequivalents (meq) of acid or base per unit volume of substrate was quantified by titration with hydrated dolomitic lime or HCl.
After 33 days, species and solution type effects on substrate-pH and estimated meq of acid or base produced were evaluated. Final substrate-pH ranged from 4.83 for geranium in 40:60 solution to 6.58 for lisianthus in 0:100 solution, compared with an initial substrate-pH of 5.84. This change in substrate-pH corresponded with a net meq of acid or base produced per gram of tissue dry mass gain (NMEQ) ranging across solutions and species from 1.47 of base for lisianthus in the 0:100 solution to 2.10 of acid for coleus in the 40:60 solution.
With the 0:100 solution, geranium produced the greatest NMEQ of acid (0.07), whereas lisianthus produced the greatest NMEQ of base (1.47). Because all N in the 0:100 solution was in the NO3− anion form, meq of both anions and cations taken up by plant roots could be calculated based on tissue analysis. With the 0:100 solution, species that took up more anions than cations into plant tissue tended to have a more basic effect on substrate-pH, as would be expected to maintain electroneutrality.
Data were used to estimate the percent NH4+-N of total N in a nutrient solution that would be neutral (results in no substrate-pH change) for each species. This neutral percent NH4+-N of total N ranged from ≈0% (geranium) to 35% (pentas). Species were separated into three clusters using k-means cluster analysis with variables related to NMEQ and anion or cation uptake.
Species were clustered into groups that had acidic (geranium and coleus), intermediate (dusty miller, impatiens, marigold, new guinea impatiens, petunia, salvia, snapdragon, and verbena), or basic (lisianthus, pansy, pentas, vinca, and zinnia) effects on substrate-pH. Evaluating the tendency to increase or decrease substrate-pH across a range of floriculture species, and grouping of plants with similar pH effects, could help predict NH4+:NO3− ratios for a neutral pH effect and assist growers in managing substrate-pH for container production.
Access the full study at HortScience.
Publication date: 9/15/2017
Other news in this sector:
Leave a comment: (max. 500 characters)
- All comments which are not related to the article contents will be removed.
- All comments with non-related commercial content, will be removed.
- All comments with offensive language, will be removed.