Horticultural crop health and yield and greenhouse soil conditions after 17 years of repeated treatments of biofumigation and solarization

Abstract

The combination of biofumigation and solarization is commonly known as biosolarization. A experience was performed from 2003 to 2019 in a greenhouse at INTA San Pedro, Buenos Aires province, Argentina (33°44'12.7"S 59°47'58.2"W). Treatments (TRAT) were applied every two years. TRAT evaluated were: 1=Control; 2= Solarization, 3= BIOROT, was a succession of organic amendments (chicken manure, broccoli, chicken manure, broccoli, tomato and pepper crop debris, mustard, tomato crop debris, broccoli), 4=BIOBRAS was based only on the use of brassicas (rapeseed, broccoli, broccoli, mustard, mustard, mustard, Brassica campestris, broccoli). The treatments were carried out in spring and during short periods in summer, so a late season tomato crop could be grown after them. The tomato hybrid used was Superman (Petoseed), except for the last season where the hybrid used was Rodeo (BHN). Fungal pathogens controlled were Pyrenochaeta lycopersici, Fusarium solani, Sclerotium rolfsii and Sclerotinia sclerotiorum, as well as nematodes like Nacobbus aberrans, Helycotylenchus and Criconemella. Fungus of Aspergillus genera were observed growing on death sclerotia of Sclerotinia sclerotiorum and Sclerotium rolfsii in BIOBRAS and BIOROT. Tomato plants in control showed higher percentage of death plants, root rots and lower root dry matter at the end of each crop. Solarization alone without adding organic matter reduced this parameter in the soil, and showed more death plants and less yield than BIOBRAS and BIOROT. Tomato and pepper crop debris used as biofumigants produced high yield values and adequate pathogen control. Beneficial organisms as Trichoderma and actinomicetes were isolated from rhizosphere of tomato growing on BIOBRAS and BIOROT soils. Good results were also obtained with other crops as lettuce, spinach, grafted tomato plants, broccoli, beets, chard, sweet potato for seedlings production, etc. Biofumigation in combination with solarization is an effective technique for managing soilborne pathogens in greenhouses and is being adopted by horticultural growers in Argentina.