Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/ plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.
A field study was conducted in order to evaluate the effects of intercropping and biofertilizers on yield and yield components of purslane (Portulaca oleracea L.) and dragon's head (Lallemantia iberica Fisch. and C.A. Mey). The experiment was factorial on the basis of a randomized complete block design with three replications. The first factor was an additive intercropping system including monocultured purslane, monocultured dragon's head, intercropping of 100% purslane + 25% dragon's head, intercropping of 100% purslane + 50% dragon's head, intercropping of 100% purslane + 75% dragon's head; the second factor was nutrient treatments including application of 50% inorganic N fertilizer (urea) + nitroxin, inorganic N fertilizer (urea), nitroxin and no fertilizer. Results showed that as the density of dragon's head increased, the number of branches in purslane decreased. In purslane, the number of capsules was significantly affected by intercropping and application of biofertilizers. In both crops, the effects of treatments on yield were significant. Results clearly showed that Relative Yield Total (RYT) was always higher in intercropping than monocultured systems. The highest RYT was observed in intercropping of 100% purslane + 50% dragon's head with the application of 50% inorganic N fertilizer (urea) + nitroxin. Therefore, combination usage of biofertilizers and inorganic N fertilizers can improve yields in purslane/dragon's head intercropping.
In production agriculture, weed plants play an important role in yield reduction. Analysis of crop growth can reveal underlying processes of yield loss under weed interference conditions. Therefore, an experiment was conducted in 2011 in order to assess the effect of weed competition on different aspects of dry bean growth. The experiment was a randomized complete block design with 3 replications. Treatments included weed-infested and weed-free periods until 0, 10, 20, 30, 40 and 50 days after crop emergence. Aboveground dry matter and leaf area were measured every two weeks. The functional approach to growth analysis was used to examine temporal patterns in crop growth in weed interference conditions. A negative relationship between weed biomass and dry bean growth indexes was observed. In all treatments, crop biomass had a similar trend and progressively increased over the crop cycle, then after reaching the maximum amount, gradually decreased. The lowest crop biomass (676.60 g m -2) was observed in season-long weed-infested treatment, while the maximum one (1238.82 g m -2) was recorded in season-long weed-free treatment. Relative growth rate (RGR) and net assimilation rate (NAR) had a declining trend during the growing season. Increase in weed-infested periods intensified decrease of them. Effect of weed competition on crop growth was trifle at the early of growing season. Since NAR and RGR represent photosynthesis potential and dry matter accumulation of the crop, their reduction can be the main cause of yield loss.
Declining land productivity associated with decreasing soil organic carbon (SOC) and nitrogen (N) are significant issues in monoculture crop production. In addition, continuous use of inorganic fertilizer often leads to unsustainability in crop production and creating environmental pollution. Considering the importance of purslane (Portulaca oleracea L.) and dragon’s head (Lallemantia iberica Fisch. & C.A. Mey) in human nutrition, a field study was carried out to assess the effects of chemical and biological fertilizers on purslane-dragon’s head intercropping. The factorial experiment was set on the basis of randomized complete block design with three replications. The first factor was an additive intercropping system including monocropping of purslane (P), monocropping of dragon’s head (D), intercropping of 100% purslane + 25% dragon’s head (PD25), intercropping of 100% purslane + 50% dragon’s head (PD50), intercropping of 100% purslane + 75% dragon’s head (PD75); the second factor was nutrient treatments including application of 50% inorganic N fertilizer (urea) + nitroxin (F1), inorganic N fertilizer (urea) (F2), nitroxin (F3) and no fertilizer (F4). For purslane crop, the highest amount of relative chlorophyll (SPAD) belonged to PD75 + F1 treatment. Intercropping increased stem height of both crop plants. The data obtained hereby clearly showed that the total yield of the purslane-dragon’s head intercropping treatments was higher than any of the monocropping treatments. PD50 + F1 had the highest amount of land equivalent ratio (LER). Therefore, intercropping of 100% purslane + 50% dragon’s head and application of 50% urea + nitroxin might be recommended for higher yield and economic return.
Field study was carried out in 2011 in west of Iran to assess responses of dry bean (Phaseolus vulgaris L.) morpho-physiological traits to gradual weed biomass accumulation. The treatments consisted of two different periods of weed interference, which weeds either infested the plots or removed for an increasing duration of time (0, 10, 20, 30, 40, 50 days) after crop emergence. Relative dominance and relative importance of weed species fluctuated over the crop cycle. As the duration of weed interference was increased, a declining trend of crop growth rate (CGR) was observed. When weeds were allowed to compete with crop throughout the crop cycle, maximum value of CGR was decreased from 25.57 g m -2 days in full season weed free treatment to 16.78 g m -2 days in full season weed infested treatment. Effect of treatments on leaf area index (LAI) was significant. Weed removal increased LAI but it could not significantly affect this trait, at the early of growing season. Weed interference caused a significant reduction on number of branches. The minimum number of branches was registered in full season weed infested treatment (2.58 branches per plant), while the maximum one was observed in the full season weed free treatment (4.25 branches per plant). Weed competition severely reduced crop yield. At 10 and 20 days after crop emergence, weed infestation could not significantly affect the yield. A negative relationship between weeds' dry matter accumulation and LAI as well as number of branches was observed which signify the vulnerability of these morpho-physiological traits to weed competition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.