Use of Trichoderma harzianum as a biocontrol agent against Rhodococcus fascian on Pelargonium A Research Proposal Submitted in Partial Fulfillment for the Requirements of the Master of Science Degree in Crop Protection John Ouma – A56/79099/2012

Introduction Europe and North America depends mainly on pelargonium cuttings imports from Africa (Serek et al,. 1998). This is due to favourable factors like cheap labour, good climate and readily available land. Pelargonium cuttings are therefore rooted and finished in importing countries (Serek et al., 1998). Therefore pelargonium production provides employment opportunities for many Kenyans. The climate in Kenya is dry and due to the high attitude the night temperatures are rather cold. This means perfect conditions for the production of pelargonium, perennial and carnation cuttings. (http://www.selectaworld.com/en/in- practice/production-sites/selecta-kenya.html). Cuttings of high quality are essential in the highly competitive market. They must be free from any default or disease. Rhodococcus fascians is one of the pelargonium diseases.

Introduction continues It is not always very deleterious for many host plants and is generally considered as mildly pathogenic (Vereecke et al 2000). However in ornamental industry where profit is based on plants aesthetic, the pathogen causes considerable losses (Vereecke et al 2000) and should therefore be effectively controlled. Unfortunately there is no efficient means of managing R fascians once the crops are affected. This situation leaves the farmers with only one option: good sanitation practices to prevent the introduction of the disease in their crop (Baker 1950; Depuydt et al. 2008). Trichoderma spp is an antagonistic fungus against many plant pathogens.

Introduction Continued It has two important modes of actions - direct suppression of the pathogen with production of antibiotics substances & enzymes and strong stimulation of the plants natural defence mechanism (Harman et al., 2004, Hurtado, 2004; Wasternack et al., 2006). Saksirirat et al, (2009) demonstrated that Trichoderma harzianum induced resistance against Xanthomonas campestris pv. Vesicatoria spots thereby reducing the bacterial spots by over 69%. Can T harzianum be used for effective control of Rhodococcus fascians on pelargonium? This is the question this project would like to address by testing the effectiveness of T harzianum in reducing R fascians incidences on pelargonium production and other horticultural crops by extension.

Justification of the Study To ensure reliable production of high quality pelargonium cuttings and young plants. R. fascians has serious quality implication on the pelargoniu in that all affected plants must be removed to avoid spreading. There is no known effective means of controlling this disease once it affects the crop.

A crop devastated by R. fascian Affected plants were rogued Mature gall on Pelargoniums

Objectives of the Study Overall Objective To manage R fascian in pelargonium production through use of T harzianum as a biocontrol agent. Specific Objectives To evaluate the effectiveness of T harzianum on controlling R fascians in pelargonium. To evaluate the effectiveness of T harzianum to induce systemic resistance against R fascians in Pelargonium zonale*.

Null Hypotheses R fascians do not significantly affect pelargonium production*. T harzanium is not effective on the control of R fascians. There is no relationship between Concentration of T harzianum and efficacy. There is no relationship between application frequency of T harzianum and efficacy.

Materials & Methods A survey to determine the significance of R fascians on pelargonium Production will be conducted in 2 farms* Questionnaires will be distributed to 2 farms that exports Pelargonium in Kenya. Questionnaires to consider production system, management practices &size of the farm Efficacy trials will be conducted at Swani farm - Thika. Rhodococcus fascians pathogen would be sourced from a culture kept in a lab* (The bacterium was tested at Naktunbouw Laboratory in Netherlands and confirmed to be Rhodococcus fascians)  

Materials & Methods Pelargonium mother stock for the experiments will be grown in 4 litre pots and will be sourced from one of the farms in Kenya. Two varieties of pelargnium will be tested (), One part of the stock will be treated with Trichoderm harzianum. Plants to be treated with the fungi would be drenched at 400 ml (1 part Triaunum: 5 parts water) per pot every week from the date of potting. 4 weeks later, all the stock treated with T harzianum and the untreated plants will be inoculated with R fascians. Plants untreated with T harzianum would act as the negative control. Treatments would be replicated 4 times. Efficacy trial will be repeated in a different site within the same Farm for confirmation of results. Number of affected plants would be counted 8 weeks from the date of R fascian inoculation. Diameter of the galls will also be measured and compared*.

TREATMENTS T. harzianum R. fascian and T. harzianum R. fascian Negative control

Budget Activity Quantity Unit cost Ksh Total cost (Ksh) Site Fee 1 30000 Data collection expenses & Labels / Planting material 10000 Subsistence and Travel 2 2000 4000 Printing papers Thesis (Draft) 1 reams 500 1,000 printing Draft / Final 200 pages 10 Photocopying 400 Binding 5 copies 50 250 GRAND TOTAL 47, 650

Work Plan Work Plan 2012/13 2013 2014 Activity J F M A S O Development of thesis proposal   Present research proposal Research Set up of experiments Data collection, entry and analysis Compile thesis first Chapters Complete experiments Data interpretation – write results chapter Compile and complete thesis Thesis submission to BPS