Özhan Boz

Olive Processing Waste as a Method of Weed Control for Okra, Faba Bean, and Onion

Abstract Field experiments were carried out during two growing seasons at Adnan Menderes University, Faculty of Agriculture, in Aydın-Turkey to evaluate the weed control efficacy of olive processing waste (OPW) in okra, faba bean, and onion. OPW was incorporated into the soil prior to seeding at 10, 20, 30, and 40 tons (t)/ha. Non-treated plots and plots treated with trifluralin in okra and pendimethalin in faba bean and onion were used for comparison. OPW suppressed common purslane, redroot pigweed, and junglerice in okra; littleseed canarygrass, annual bluegrass, wild chamomile, and shepherds-purse in faba bean and onion. OPW was in most cases equally as effective as soil herbicides; however, 10 t/ha provided sometimes lower efficacy than herbicides. OPW had no negative effects on okra and faba bean, while onion was negatively affected by doses over 30 t/ha. Overall, OPW can be applied at 10 to 20 t/ha doses for weed control with adequate crop safety. Nomenclature: Pendimethalin; trifluralin; annual bluegrass, Poa annua L.; common purslane, Portulaca oleracea L.; junglerice, Echinochloa colona (L.) Link.; littleseed canarygrass, Phalaris minor Retz.; redroot pigweed, Amaranthus retroflexus L.; shepherds-purse, Capsella bursa-pastoris (L.) Medik.; wild chamomile, Matricaria chamomilla L.; faba bean, Vicia faba L.; okra, Abelmoschus esculentus (L.) Moench; onion, Allium cepa L.; olive, Olea europaea L.

Weed hosts of Verticillium dahliae in cotton fields in Turkey and characterization of V. dahliae isolates from weeds

A weed survey conducted in 2004 and 2005 in Aydin province of Turkey showed that Solanum nigrum, Xanthium strumarium, Amaranthus retroflexus, Portulaca oleracea, Sonchus oleraceus and Datura stramonium were the most prevalent weeds in the cotton fields exhibiting Verticillium wilt. Verticillium dahliae Kleb. was recovered from A. retroflexus and X. strumarium in those cotton fields. This is the first report of V. dahliae occurring naturally in A. retroflexus in Turkey. Pathogenicity tests on cotton and weeds showed that the virulence of V. dahliae isolates from weeds was higher on cotton plants than on weeds, with the disease severity ranging from 31.7% to 98.0%. Disease severity of V. dahliae isolates was 54.7–93.9% on eggplant, 23.7–51.6% on cucumber and 11.0–16.4% on tomato, whereas it did not cause any disease symptoms, or only low levels, on pepper and bell pepper. Two vegetative compatibility groups (VCGs) were identified among seven tested weed isolates: VCG2A (two isolates) and VCG2B (three isolates) using international reference strains.

Effects of olive processing waste, chicken manure and Dazomet on weeds with or without soil solarisation

Three non-chemical weed control alternatives (chicken manure (10 t ha-1), olive processing waste (OPW) (30 t ha-1), and solarisation (6-7 weeks at > 40.9 - 47.1oC at a 15 cm soil) were applied to greenhouse grown tomatoes alone and in combination and were compared with a soil fumigant (dazomet) for the ability to control weeds. Both dazomet (485 kg a.i. ha-1) and solarisation provided excellent control of common purslane, slender amaranth and bristly foxtail. Excellent weed control was also achieved with a half dose of dazomet (242.5 kg a.i. ha-1) plus 21 days of solarisation. OPW provided moderate control of these weeds, but chicken manure did not. OPW and chicken manure applied with solarisation provided 100% control of common purslane, slender amaranth and bristly foxtail, but did not significantly improve control compared to solarisation alone. OPW plus a short-duration of solarisation may provide weed control that is comparable to dazomet in greenhouse grown tomatoes.

Soil disinfestation options in Aydın province, Turkey, strawberry cultivation

Two field experiments were conducted in the two successive seasons of 2005/2006 and 2006/2007 in strawberry-growing areas of Aydin province of Turkey to (a) compare soil solarization and metam sodium (MS) combinations with low-density polyethylene (LDPE) and virtually impermeable film (VIF); and (b) evaluate strawberry fruit yield, soilborne disease and weed control efficacy. Disinfestation treatments were as follows: (i) raised bed solarization for about 6 weeks, (ii) raised bed solarization for 3 weeks, (iii) raised bed solarization for 2 weeks + MS (50 ml m-2), (iv) MS (50 ml m-2) with LPDE (v) MS (100 ml m-2) with LDPE, (vi) MS (50 ml m-2) with VIF, (vii) MS (100 ml m-2) with VIF. Results indicated that Macrophomina phaseolina and Fusarium spp. were the major fungal pathogens isolated from the crown of dead or dying plants in both cropping seasons. MS treatment (100 ml m-2) through the drip irrigation system under LDPE sheet or VIF reduced soilborne diseases significantly while reduced dosage of MS (50 ml m-2) under LDPE or VIF and in combination with 2-week soil solarization controlled the soilborne diseases to a greater extent than soil solarization treatments. All treatments controlled the following weed species: Portulaca oleracea, Amaranthus spp., Poa annua, Alopecurus myosuroides, Matricaria chamomilla, Digitaria sanguinalis, Raphanus raphanistrum, Seteria verticillata, Chenopodium album, Stelleria media, Capsella bursa-pastoris, Echinochloa cruss-galli, Veronica hederifolia, Lamium amplexicaule and Silybum marianum. None of the treatments provided acceptable control of horseweed (Conyza canadensis). Metam sodium application (100 ml m-2) significantly increased yields by 18.5% and 14.5% in the 2005/2006 and 21.6% and 18.5% in the 2006/2007 season under LDPE and VIF, respectively, while marketable fruit yield was not significantly increased by soil solarization treatments in either trial. There was no significant difference between MS applications under LDPE and VIF for the weed and disease control, and marketable fruit yield.