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Critical period of weed competition in sorghum under fertilized (F1) and unfertilized (F0) conditions.
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Weeds are among the most harmful factors limiting sorghum production under Sudanian conditions of southern Senegal. Despite, the taxonomic structure of the flora is relatively well known, few studies have focused on crop-weed competition. Field experiment was carried out to determine the critical time for weed competition in grain sorghum. Ten trea...
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... findings indicated that weed control measures in sudanian zone of Senegal begin 15 days after sowing till 45 and 55 days after sowing under traditional cropping system and 10-55 days after sowing under conventional system (Figure 2). During this critical period of weed control, sorghum should be kept weed free to avoid losses that can range from 10 to 96% of grain yield. ...
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Weed interference is one of the factors that reduces carrot yield considerably. The aim of this study was to determine the periods of weed interference in carrots cultivated under two localized irrigation systems. The experiment used a completely randomized block design, with three replications, using the split plot scheme. The plots consisted of t...
Citations
... This might be due to better availability of moisture and nutrients to the crop under better control of weeds throughout the crop growth period resulting in more favorable conditions for the crop, consequently, the crop attained more growth having a smothering effect on weeds. Similar findings by Seyyedi et al. [35] indicated that weed-free until maturity results in an increase in the height of black seed by 30 %. Increased weed-free duration increased the dry matter accumulation of sorghum Laha et al. [36], and groundnut also [17]. However, season-long weedy plots reduced the crop growth, which might be due to severe crop-weed competition for resources like solar radiation, nutrients uptake, space, moisture etc., consequently plant height, dry matter accumulation, CGR, and chlorophyll content were adversely affected. ...
... However, season-long weedy plots reduced the crop growth, which might be due to severe crop-weed competition for resources like solar radiation, nutrients uptake, space, moisture etc., consequently plant height, dry matter accumulation, CGR, and chlorophyll content were adversely affected. These results are correlated with earlier findings in fenugreek [37], sorghum [36], parsley [38][39][40]. Also, early-grown weeds cover the canopy of crops due to their shading effect, reducing the crop chlorophyll content [41][42][43]. ...
The critical period of crop-weed competition (CPCWC) varies by cultivars, management strate-
gies, cropping seasons, soil, and climate. Hence, a study was done to assess CPCWC in green gram
under different cropping seasons and its impact on nutrient mining, agro-physiological charac-
teristics, and productivity of green gram during the summer and rainy seasons. The experiment
comprised of 12 treatments (weed interference until 10, 20, 30, 40, 50 days after sowing (DAS)
and crop maturity, weed-free until 10, 20, 30, 40, 50 DAS and crop maturity). The treatments
were placed in a randomized complete block design (RCBD) with three replications
... Zimdahl et al. (1988) opined that CPWC is not an inherent property of a crop and can vary depending on weed species, site, specific crop and even season. Ka et al. (2020) reported the CPWC for sorghum between 15-45 and 15-55 DAS under unfertilized conditions and 10-55 and 15-55 DAS under fertilized conditions. Elamin et al. (2019) reported that the critical period of weed-okra competition was between 6 and 8 weeks after sowing. ...
A field experiment was conducted to investigate the pea-weed competition which revealed a significant reduction in pea yield with increasing duration of crop weed competition. The weed density in the season-long weedy plot was found to increase up to 60 days after sowing (DAS) and decreased thereafter. However, the weed dry matter accumulation increased progressively with duration of the weedy period. Galinsoga parviflora was the most dominant weed species as indicated by higher values of summed dominance ratio (SDR) in all the treatments. Relative yield loss (RYL) in peas was predicted using logistic and Gompertz equations in weed and weed free set of treatments, to determine 21 to 48 DAS as the beginning and end of the critical period of pea-weed competition, respectively, which is equivalent to 260 to 510°C day growing degree days (GDD). The economic threshold (ET) for multi-weed species for pea crop was estimated to range between 2.15 to 20.91 plants/m 2 .
... Generally, the first stages of growing wheat yield, ranging from 4-10 weeks, are very effective in determining the yield ability of the wheat crop to the accompanying weeds (Hammood & Safi, 2018). Plant height, biomass, and yield significantly decreased with each increase in competition (Ka et al., 2020). ...
... Wheat yield decreased by increasing competition period, thus weed-free treatment gave the highest grain yield 2.78ton ha -1 and the lowest one was found in weedy treatment 1.35ton ha -1 (Riya et al., 2017). The results are following the findings of (Girma & Adare, 2019) on barley and (Ka et al., 2020) on sorghum. ...
Moong bean is one of the important pulse crop in world and India. It is cultivated in various states of India in summer and kharif. Weeds are major threat to moong bean productivity in both seasons. Hence, this study was conducted to know the effect of crop-weed conflict on growth and productivity of moong bean. The experiment was set up with initial weedy and initial weed-free treatments with three replications using a randomized block design in summer seasons of 2022. The results were indicated that the increased weed interference period decreased the moong bean height by 0.30-10.27%, nodules per plant by 1.13-17.47%, fresh weight of nodule by 0.58-5.48%, dry weight of nodules by 1.32-10.58%, SPAD index by 15.18-43.57%. Similarly, 2.52 to 75.45% and 2.80-13.73% respectively, grain and stover yield decreased.
