The effect of nitrogen source on in vitro growth of Neonectria ditissima (European canker)
Nitrogen fertilisers are widely used in apple orchards. However, the effects of various nitrogen sources on growth and sporulation of the fungus Neonectria ditissima, which causes European canker, are not fully understood. The effects of various nitrogen sources commonly used in apple orchards (potassium nitrate, ammonium chloride, ammonium nitrate, ammonium sulphate, NitrophoskaÂ® and urea) on percent germination and germtube growth of N. ditissima conidia were tested in vitro. Nitrogen concentrations below 0.2 mol/L did not significantly affect percent conidial germination; however, concentrations above 0.2 mol/L significantly decreased germination. Germtube growth was also affected, generally decreasing with increased N. Percent germination was influenced by the N source, but germtube growth was not. Very low concentrations of urea were indicated to stimulate germtube growth. Higher concentrations, showed toxic effects on both germination and germtube growth. The presence of exogenous N from various sources did not affect initial germination and growth in the N. ditissima infection process of apple tissues.
Amponsah NT, Walter M, Scheper RWA 2014. Agar media for isolation of <em>Neonectria ditissima</em> from symptomatic and asymptomatic apple tissues and production of infective conidia. New Zealand Plant Protection 67:116–122.
Beresford RM, Horner IJ, Wood PN 2000. Autumn-applied urea and other compounds to suppress <em>Venturia inaequalis</em> ascospore production. New Zealand Plant Protection 53: 382–392.
Burchill RT 1968. Field and laboratory studies of the effect of urea on ascospore production of <em>Venturia inaequalis</em> (Cke.) Wint. Annals of Applied Biology 62(2): 297–307. <a href="https://doi.org/10.1111/j.1744-7348.1968.tb02825.x">https://doi.org/10.1111/j.1744-7348.1968.tb02825.x</a>
Dryden GH, Nelson MA, Smith JT, Walter M 2016. Postharvest foliar nitrogen applications increase <em>Neonectria ditissima</em> leaf scar infection in apple trees. New Zealand Plant Protection 69: 230–237.
Fagard M, Launay A, Clement G, Courtial J, Dellagi A, Farjad M, Krapp A, Soulie MC, Masclaux-Daubresse C 2014. Nitrogen metabolism meets phytopathology. Journal of Experimental Botany 65(19): 5643–5656. <a href="https://doi.org/10.1093/jxb/eru323">https://doi.org/10.1093/jxb/eru323</a>
Hill-Cottingham DG, Bollard EG 1965. Chemical changes in apple tree tissues following applications of fertiliser nitrogen. New Zealand Journal of Agricultural Research 8(4): 778–787. <a href="https://doi.org/10.1080/00288233.1965.10423713">https://doi.org/10.1080/00288233.1965.10423713</a>
Huber DM, Watson RD 1974. Nitrogen form and plant disease. Annual Review of Phytopathology, 12:139–165. <a href="https://doi.org/10.1146/annurev.py.12.090174.001035">https://doi.org/10.1146/annurev.py.12.090174.001035</a>
Matsushima T 1961. A new medium for identification of hyphomycetes. Transactions of the Mycological Society of Japan 2: 118–120.
Orchard S, Campbell RE, Turner L, Butler RC, Curnow T, Patrick E, Walter M 2018. Long-term deep-freeze storage of <em>Neonectria</em> <em>ditissima</em> conidium suspensions does not reduce their ability to infect apple trees. New Zealand Plant Protection 71: 158-165.
Scheper RWA, Fisher BM, Amponsah NT, Walter M 2014. Effect of culture medium, light and air circulation on sporulation of <em>Neonectria ditissima</em>. New Zealand Plant Protection 67: 123–132.
Siddig AA, Osman IM, Ali EM 2013. Effects of variety, nitrogen form and application timing of fungicide on early blight disease on tomato. Global Journal of Biology, Agriculture and Health Sciences 2(3): 241–248.
Swinburne TR 1975. European canker of apple (<em>Nectria galligena</em>). Review of Plant Pathology 54: 787–799.
Veverka K, Stolcova J, Ruzek P 2007. Sensitivity of fungi to urea, ammonium nitrate and their equimolar solution UAN. Plant Protection Science 43(4): 157–164. <a href="https://doi.org/10.17221/2239-PPS">https://doi.org/10.17221/2239-PPS</a>
Walter M, Stevenson OD, Amponsah NT, Scheper RWA, Rainham DG, Hornblow CG, Kerer U, Dryden GH, Latter I, Butler RC 2015. Control of <em>Neonectria ditissima</em> with copper based products in New Zealand. New Zealand Plant Protection 68: 241–249.
Walter M, Roy S, Fisher BM, Mackle L, Amponsah NT, Curnow T, Campbell RE, Braun P, Reineke A, Scheper RWA 2016. How many conidia are required for wound infection of apple plants by <em>Neonectria ditissima</em>? New Zealand Plant Protection 69: 238–245.
Weber RWS 2014. Biology and control of the apple canker fungus Neonectria ditissima (syn. N. galligena) from a Northwestern European perspective. Erwerbs-Obstbau 56: 95–107. <a href="https://doi.org/10.1007/s10341-014-0210-x">https://doi.org/10.1007/s10341-014-0210-x</a>
Wermelinger B, Oertli JJ, Delucchi V 1985. Effect of host plant nitrogen fertilization on the biology of the twoâ€spotted spider mite, Tetranychus urticae. Entomologia Experimentalis et Applicata 38: 23–28. <a href="https://doi.org/10.1111/j.1570-7458.1985.tb03493.x">https://doi.org/10.1111/j.1570-7458.1985.tb03493.x</a>
Wood PN, Beresford RM, Taylor TJ 2008. Suppression of Venturia inaequalis (apple scab) ascospore production using autumn-applied fungicides. New Zealand Plant Protection 61: 54–58.