- Finance Director - Ukraine
- Sales Manager and Quality Assurance Supervisor
- Breeder (MSc) - Hann. Münden, Germany
- Buitendienst Medewerker - België
- Assistant Grower Manager Tomato & Capsicums - Malaysia Highlands
- Assistant Grower Manager Lettuce & Herbs - Malaysia Highlands
- Trainee Production Management - starting location Ethiopia
- Сhief technologist, Tula region - Russia
- Сhief technology officer, Tula region - Russia
- Controller Technician / Electrician - Horticulture, Australia
Top 5 -yesterday
Top 5 -last week
Top 5 -last month
Nutritional factsheet geraniums
Geraniums require medium levels of fertility. Growers should provide fertilization at 150 to 200 ppm N. Low soluble salts [referred to as electrical conductivity (EC)] from inadequate fertilization can cause yellowing (chlorosis) or reddening on the lower foliage. High EC is an issue during propagation, as cuttings and seedlings are sensitive to root burning (plasmolysis) and lower leaf browning (necrosis). For this reason, fertilization should be maintained at 100 ppm N during propagation (Dole and Wilkins, 2005). Excess salts may build up in the substrate during stock plant production, leading to plasmolysis and lower leaf necrosis. Frequent leaching with clear water should be implemented to control EC and prevent symptom development (Dole and Wilkins, 2005).
Substrate pH should be maintained between 5.8 and 6.5. Values beyond this range commonly lead to high or low pH induced nutritional disorders (Whipker and Henry, 2017). High pH inhibits iron (Fe) uptake, causing interveinal chlorosis of the upper foliage. Low pH causes excessive uptake of Fe and manganese (Mn), which leads to toxicity symptom development. Symptoms of Fe and Mn toxicity include a lower leaf bronzing with dark brown to black spotting.
Foliar Fe and Mn concentrations should remain below 500 ppm (Dole and Wilkins, 2005). Previous reports of low pH induced Fe and Mn toxicity document foliar concentrations of these two elements to be ~10× higher than in asymptomatic plants (Henry and Whipker, 2016). Monitoring substrate pH and periodic tissue sampling can help to determine if symptoms are due to high or low Fe and Mn. Iron deficiency can be remedied with an application of Fe chelate, while Fe and Mn toxicity can be remedied by providing flowable lime to raise the pH.
Download the factsheet from eGro.
Publication date :
Receive the daily newsletter in your email for free | Click here
Other news in this sector:
- 2018-12-11 The Soil Food Web for greenhouse production: bringing biology into the equation
- 2018-12-06 URALCHEM expands its presence in Africa
- 2018-11-27 Kenya: "Crisis looms in flower farms as fertilizer shortage bites"
- 2018-11-22 "Much wood fibre in a small space"
- 2018-11-20 Kenya: Small fertiliser factory takes on the big boys
- 2018-11-06 Chrysal introduces sustainable flower food sachets
- 2018-10-23 Kenya: Fertilizer prices up on port delays
- 2018-10-22 TerraVesco Vermicompost now available in Canada
- 2018-10-22 Kenya: Exports likely to dip due to fertilizer shortage
- 2018-10-12 "Economic benefits with CO2 foliar spray integrated into irrigation booms"
- 2018-10-10 US: MycoApply Ultrafine Endo now available in 1 lb. bags
- 2018-10-04 Irish fertilizer company enjoys rapid expansion in the UK
- 2018-09-27 Bomenbank launches Lifechar – the next generation of Amsterdam tree soil
- 2018-09-14 Kenya: Oserian Flowers raises alarm over biting fertilizer shortage
- 2018-09-14 Kenya: Speed up fertiliser checks, orders State
- 2018-09-12 Kenya: Fertilizer shortage blamed on 'scam'
- 2018-08-24 "Keep a few plants away from your fertilizer trial"
- 2018-08-10 e-GRO launches Nutritional Monitoring of Floriculture Crops book
- 2018-08-10 Monitoring pH & EC of greenhouse crops
- 2018-08-07 Video: Osmocote longevity - Controlled release fertilizer