Competitive interaction between red beet and weeds, as affected by different weeding time

D. Kavaliauskaitė, J. Jankauskienė, E. Survilienė, O. Bundinienė,R. Starkutė, V. Zalatorius and R. Karklelienė

Lithuanian Institute of Horticulture, Kauno str. 30, LT-543333, Babtai, Kaunas distr., Lithuania,telephone: +370-37-555-226, fax: +370-37-555-176, e-mail: d.kavaliauskaite@lsdi.lt

Abstract:

The competitive interactions between two red beet cultivars (‘Pablo F ’, prostrate,1and ‘Kamuoliai’, ect.) and weeds, affected at different weeding times, were studied for three years at the Lithuanian Institute of Horticulture. In all years, a long period of weeding gave lower crop biomass reduction of both cultivars. When weeding was delayed from 2 to 12 weeks after red beet germination the crop biomass of both cultivars was reduced by much more than half. From weed density studies, crop competition during long period of weeding reduced the number of germinating weed species and lowered seed germination of Chenopodium album L., Galinsoga parviflora Cav., Cappsella bursa-pastoris (L.) Medik., Stellaria media (L.) Vill. The two cultivars of red beet showed the same response to competition.

Key words:

competitive interaction, red beet, weed

Determination of weed competition critical period in red beet

D. Kavaliauskaitė and Č. Bobinas

Lithuanian Institute of Horticulture, LT-54333 Babtai, Kauno 30, Kaunas distr.,e-mail: d.kavaliauskaite@lsdi.lt

Abstract:

The field experiment was conducted at the Lithuanian Institute of Horticulture from 2000-2002 to determine the critical period of weed competition in red beet (Beta vulgaris L.) hybrid ‘Pablo’ crop. Weeding was delayed until 2, 4, 6, 8, 10, 12 weeks after red beet germination (WAG) and was carried out during the first 2, 4, 6, 8, 10, 12 WAG. Weed competition during the first 10 to 12 WAG reduced the marketable yield of red beet by 100%. Competition in the first 8 WAG reduced yield by 92.2%. Competition in the first 2 WAG had no adverse effect on yield; there was only an 8.3% reduction of red beet yield. A period of weeding for 4 WAG provided a yield similar to that achieved with 6 weeks of weeding. It is concluded that the first 4 WAG are the most critical for weed competition in red beet crop at a 5% yield loss level. Weeds emerging later do not appear to be detrimental to red beet growth and marketable yield.

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