Agroindustrial composts to reduce the use of peat and fungicides in the cultivation of muskmelon seedlings.

BACKGROUND

Environmental concerns about peat extraction in wetland ecosystems have increased. Therefore, there is an international effort to evaluate alternative organic substrates for the partial substitution of peat. The aim of this work was to use different composts (C1-C10) obtained from the fruit and vegetable processing industry (pepper, carrot, broccoli, orange, artichoke residues, sewage sludge (citric and pepper) and vineyard pruning wastes) to produce added-value composts as growing media with suppressive effect against Fusarium oxysporum f.sp. melonis (FOM) in muskmelon.

RESULTS

Composts showed values of water-soluble carbon fractions and dehydrogenase activity that allowed them to be considered mature and stabilized. All compost treatments produced significantly (F = 7.382; P < 0.05) higher fresh shoot weight than peat, treatment T-C2 showing the highest values. Treatments T-C5, T-C7 and T-C8 showed percentages of disease incidence that were significantly (F = 16.052; P < 0.05) the lowest, relative to peat, followed by T-C6, T-C10, T-C1 and T-C9 with values below 50%.

CONCLUSIONS

Composts produced are suitable components of mixed compost-peat growing media, providing a 50% substitution of peat. Furthermore, some of these composts also showed an added value as a suppressive organic medium against Fusarium wilt in muskmelon seedling, a fact probably related to high pH and pepper wastes and high content of pruning waste as initial raw materials. © 2016 Society of Chemical Industry.