Article

The effect of harpin protein on plant growth parameters, leaf chlorophyll, leaf colour and percentage rotten fruit of pepper plants inoculated with Botrytis cinerea

Department of Plant Protection, Uludag University, Boursa, Bursa, Turkey
Scientia Horticulturae (Impact Factor: 1.5). 06/2006; 109(2):107-112. DOI: 10.1016/j.scienta.2006.03.008

ABSTRACT In this study, harpin protein was applied to the peppers (Capsicum annuum L. var. cvs. ‘Demre’, ‘Yalova Charleston’ and ‘Sari Sivri’) grown under natural conditions. These plants were subjected to artificial inoculation with Botrytis cinerea, which causes fruit spoilage in peppers. Changes in vegetative growth, total chlorophyll content in leaves, leaf colour and percentage of rotten fruits were determined after treatments. The number of leaves per plant value was quite low in all cultivars and the plant height value was low only in cv. ‘Sari Sivri’ treated with B. cinerea. Values obtained from vegetative growth parameters in the plants subjected to harpin protein + B. cinerea treatment were only higher than B. cinerea treatment. Leaf chlorophyll values exhibited significant decline in the plants subjected to B. cinerea treatment in all cultivars. However, the chlorophyll content in the plants subjected to harpin protein + B. cinerea treatment was low. The colour values obtained from leaves supported the chlorophyll findings. Fruit spoilage percentages were lower in the fruits picked from the plants of harpin protein + B. cinerea treatment compared with those picked from the plants only subjected to B. cinerea treatment.

0 Followers
 · 
808 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 2 year field trial was conducted using established English oak (Quercus robur L.) to assess the efficacy of four commercially available systemic-inducing resistance (SIR) compounds (salicylic acid, potassium phosphite, harpin protein, be- taine) applied as a single therapeutic spray treatment against the foliar pathogen oak powdery mildew (Microsphaera alphitoides). In addition, a comparative evaluation of a conventional spray program (3 week spray intervals) used within the United Kingdom for powdery mildew control was conducted using the fungicide penconazole. The SIR-inducing compound containing betaine and a single spray treatment of penconazole had no significant influence on disease severity and specific activity of peroxidase and superoxide dismutase in both the 2005 and 2006 trials. Salicylic acid and potassium phosphite had no significant long-term effect on disease severity, although a short-term reduction in disease severity was recorded that was associated with enhanced leaf peroxidase and superoxide dismutase activity. A single therapeutic application of the SIR-inducing agent harpin protein signifi- cantly reduced disease severity of powdery mildew in the 2005 trial. No significant effects, however, were recorded in the 2006 trial. Only repeat spray applications of penconazole significantly reduced disease severity of oak powdery mildew in the 2005 and 2006 trials. The fungicide penconazole appears also to posses marginal SIR properties.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Harpin protein is an elicitor of hypersensitive response in plants. When applied exogenously, harpin is claimed to control plant diseases, increase plant growth and yield, and reduce postharvest fruit decay. The plant responses to harpin application have been inconsistent. This study was intended to determine the effects of harpin on plant growth, gas exchange, control of Phytophtora blight, fruit yield, and control of postharvest fruit decay in bell pepper (Capsicum annum L.). When applied only before planting, harpin increased marketable yield of bell pepper, but when applied both before and after planting, it reduced marketable and total yields. Harpin had no beneficial effect on plant growth, leaf mineral nutrient content, leaf gas exchange, incidence of Phytophtora blight in the field, and incidence of softrot of fruit after harvest. Harpin had little or no positive effect on most plant attributes in bell pepper in the field or after harvest.
    Communications in Soil Science and Plant Analysis 11/2008; 39(19-20):2861-2872. DOI:10.1080/00103620802432782 · 0.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A detached leaf bioassay was used to determine the influence of several film forming polymers and a conventional triazole fungicide on apple scab (Venturia inaequalis (Cooke) G. Wint.) development under laboratory in vitro conditions, supported by two field trials using established apple cv. Golden Delicious to further assess the efficacy of foliar applied film forming polymers as scab protectant compounds. All film forming polymers used in this investigation (Bond, Designer, Nu-Film P, Spray Gard, Moisturin, Companion PCT12) inhibited germination of conidia, subsequent formation of appressoria and reduced leaf scab severity using a detached leaf bioassay. Regardless of treatment, there were no obvious trends in the percentage of conidia with one to four appressoria 5 days after inoculation. The synthetic fungicide penconazole resulted in the greatest levels of germination inhibition, appressorium development and least leaf scab severity. Under field conditions, scab severity on leaves and fruit of apple cv. Golden Delicious treated with a film forming polymer (Bond, Spray Gard, Moisturin) was less than on untreated controls. However, greatest protection in both field trials was provided by the synthetic fungicide penconazole. Higher chlorophyll fluorescence Fv/Fm emissions in polymer and penconazole treated trees indicated less damage to the leaf photosynthetic system as a result of fungal invasion. In addition, higher SPAD values as measures of leaf chlorophyll content were recorded in polymer and penconazole treated trees. Application of a film forming polymer or penconazole resulted in a higher apple yield per tree at harvest in both the 2005 and 2006 field trials compared to untreated controls. Results suggest application of an appropriate film forming polymer may provide a useful addition to existing methods of apple scab management.
    Crop Protection 01/2009; 28(1):30-35. DOI:10.1016/j.cropro.2008.08.005 · 1.49 Impact Factor
Show more