Effect of Weed Emergence Time and Intervals of Weed and Crop Competition on Potato Yield

Abstract

A field study was conducted at Vezaiciai branch of the Lithuanian Institute of Agriculture from 1998 to 2000 to determine weed emergence dynamics in potato and to estimate the effect of different intervals of weed crop competition on potato tuber yield if regular interrow cultivation was applied. Treatments varying in intervals of weed-free conditions and competition were laid out in a randomized complete block design with six replications. The greatest emergence of annual broadleaf such as common lambsquarters and other weeds (62 to 86% of the season total) in the crop was observed in the period from potato planting until flowering. Emergence of winter annuals such as field violet and scentless mayweed was greatest in the period from the 20-cm potato plant height until harvesting. The 20-cm potato height was the most important stage affecting potato yield loss due to weed competition. Potato yield losses due to weed competition were minimized when weeds were removed before the potatoes reached 20 cm or kept clean from this point forward. The results indicated that the critical weed-free period, when weed competition was detrimental to yield, started from planting and lasted until 25 d after flowering.

Critical period for weed control in potatoes in the Huambo Province (Angola)

“…Most of the previous studies reported lower yield losses when weeds competed throughout the season (Saghir & Markoullis, 1974;VanGessel & Renner, 1990;Baziramakenga & Leroux, 1998;Ciuberkis et al, 2007). The low fertility of the soils in the region is well documented (Asanzi et al, 2006), but considering the high amounts of fertilizers applied during the study, the reasons that affected potato tuber number and growth, or possibly the number of active haulms per plant (data not recorded) could be various -e.g.…”

“…Critical periods of weed-crop competition for potatoes have been determined in a few environments, and only for some weed species (Saghir & Markoullis, 1974;Nelson & Thoreson, 1981;Thakral et al, 1989;VanGessel & Kenner, 1990;Baziramakenga & Leroux, 1998;Ciuberkis et al, 2007;Costa et al, 2008). In general, the critical period for weed removal in potatoes was about 4 and 6 weeks after planting, but Costa et al (2008) reported that, in Brazil, the critical period for weed interference was just one day, from 20 to 21 days after tuber planting.…”

Determination of the critical period of weed control in potato (Solanum tuberosumL.)

“…Baziramakenga & Leroax (1994) reported that to achieve 90% of highest tuber yield, the maximum time permitted for weeds to grow after potato emergence was 15 days, and the same level of tuber yield could be obtained if the crop was kept free of weeds from its emergence until 23-68 days. Ciuberkis et al (2007) showed that the CPWC in potato began at time of planting until 25 days after flowering. However, due to the variations in climatic conditions and weed flora, the results of other studies conducted in different environments or various crops may not apply to other systems.…”

Phytosociological Survey of Weeds in Areas of Crop-Livestock Integration

“…The dynamics of occurrence of weeds was changed with the advancement of the concepts of use of agricultural areas, from monocultures with soil preparation to crop rotation, tillage and crop-livestock integration because in these areas the environment is constantly changing according to its use. In this diversity of cultures and weed species is needed to understand which species can cause problems to focus on control techniques in the man-agement of these species as well as knowing which the weeds companions of the system, and no more alone [1].…”