Effect of four composts on Meloidogyne incognita and Fusarium solani infesting Superior grapevine and their influence on yield production and quality

Abstract

Four commercial composts (El-Wady®, El-Kattamyia®, Bio-green® and Organic Complementary®) prepared from food industry residues, town refuse organic matter, poultry droppings and sugar cane residues, respectively, were tested for their efficacy in suppressing root knot and root rot diseases caused by Meloidogyne incognita and Fusarium solani, respectively. The two pathogens were found infesting ten-year-old grapevines cv. Superior planted in newly reclaimed sandy soil under a drip irrigation system. The impacts of the composts were studied on plant growth variables and yield production when incorporated into the soil at the rates of 1.5, 3.0 and 6.0 kg/grapevine plant during two successive seasons (2007 and 2008). The addition of composts to soil significantly suppressed populations of the root-knot nematode in soil and roots as well as gall formation, with Organic Complementary compost being the most effective in controlling second stage juveniles of M. incognita in soil and roots, followed by El-Wady, Bio-green and El-Kattamyia composts, respectively. The greatest suppression of root galls was exhibited by Bio-green compost followed by Organic Complementary, El-Kattamyia and El-Wady composts, respectively. All composts and doses significantly suppressed F. solani in soil and enhanced soil mycoflora, which was composed of Aspergillus niger, A. terreus, Penicillium chrysogenum, P. citrinum and P. corylophilum, and decreased the infection of new grapevine roots by F. solani. All composts enhanced plant leaf area and cane thickness, increased nitrogen, phosphorous and potassium content of leaves and improved both physical and chemical characters of clusters and berries. Total soluble solids (TSS), Total acidity (TA), TSS/TA ratio and grape yield were also increased.