Natural chestnut tannins to enhance tobacco nutrition and resistance to nematodes

There is an increasing interest toward non-chemical inputs for tobacco, and the other major crops, in order to minimize leaf residues, manpower safety, environmental hazard, and crop footprint. Increasing costs of phosphate fertilizers, and reduced nematicide options under agro-environmental measures regulated cropping practices (so-called PSR 2007-2013 plan) in EU have made growers particularly concerned about present and future availability, and permission of use, of ordinary agrochemicals. Natural chestnut tannins (NCT), hot water-extracted from untreated wood, and membrane-concentrated to 17% DM, were investigated as a natural alternative for their starter effect and nemastat activity (Meloidogyne spp.). Extensive field tests on Virginia Bright tobacco were carried out in 2011 at Fattoria Autonoma Tabacchi of Città di Castello, under different conditions (soils and tobacco cvs.). Tests compared NCT with ordinary treatments, to investigate effect and costs of the different options. Early applications of NCT: in transplant water, or in mixture with the at-planting herbicide, or by other localized application methods, give an interesting starter effect, comparable to an ordinary fertilizer treatment. When conditions were prone to nematode attacks, results indicated that NCT, applied as the previosly indicated treatments and microirrigation, determined a good control at costs comparable or better than ordinary agrochemicals. NCT is presently labeled in Italy as a natural soil and water corrective, with claims on their starter effect and nemastat action as secondary effects. A twin-pack NCT-azadirachtine was also developed, as their joint application enhances the nematicide and nemastat actions of the mixture quite a lot.