Journal Paper

Paper Information

video

sound

Persian Version

View:

189

Download:

0

Cites:

Information Journal Paper

Title

EMERGENCE MODELING OF DOMINANT WEEDS IN CANOLA (BRASSICA NAPUS L.) FARMS IN PAKDASHT AND SABA-SHAHR REGIONS BASED ON THERMAL MODELS

Pages

 Start Page 1 | End Page 16

Abstract

 Introduction: The timing with which weeds emerge is one of the most important factors in competition (Baghestani and Zand, 2004). Weeds that emerge at the same or approximate time as crops inflict the most damage (Eslami et al., 2006). Models can predict the emergence time (Leon et al., 2004, Dorado et al., 2009). The goal of the present study is to investigate the emergence model of weeds (blade and flag leaf) in two different regions, Saba-Shahr and Pakdasht, based on thermal models. Beyond that, if possible, another goal is to recommend the best weed emergence models for predicting the timing of weed emergence in these regions.Materials and methods: The experiment was carried out based on a complete randomized block design with four replications in two regions, Saba-Shahr and Pakdasht fields, in 2010-11. The weeds included blade leaves Sinapis arvensis L. (wild mustard), Raphanus raphanistrum L. (WILD RADISH), DESCURANIA SOPHIA L., and flag leaf (Phalaris minor). For the examination of weed emergence, different models were used such as sigmoidal, logistic, Gompertz, a three-parameter Weibull and a four-parameter Weibull based on growing degree days (GDD). Root mean square error (RMSE), coefficient of determination and the corrected AKAIKE information criterion (AICc) were used to find the appropriate model(s).Results and discussion: The result showed that the emergence model and weed growth in the two regions were different. The best models, based on the lowest RMSE, AICc and adj R2 were Gompertz and sigmoid for predicting weed emergence in Pakdasht and Saba-Shahr. The emergence rate of weeds in Saba-Shahr showed that WILD RADISH was the first (40 GDD) to emerge among the weeds. After that, WILD MUSTARD needed 50 GDD and PHALARIS MINOR needed 60 GDD to emerge. The emergence of DESCURANIA SOPHIA needed 150 GDD, and for this reason had delayed growth. In Pakdasht, WILD RADISH was also the first weed to emerge (110 GDD). WILD MUSTARD and PHALARIS MINOR both emerged with 115 GDD and DESCURANIA SOPHIA (180 GDD) was seen after that.Conclusion: The results of this study showed that in the two regions, with the emergence of WILD RADISH, WILD MUSTARD, PHALARIS MINOR and DESCURANIA SOPHIA, interference crops must be planted earlier for increasing interference capability. On the other hand, the control of WILD RADISH, WILD MUSTARD and PHALARIS MINOR was more important than the control of DESCURANIA SOPHIA.

Cites

  • No record.
  • References

  • No record.
  • Related Journal Papers

    Related Seminar Papers

  • No record.
  • Related Plans

  • No record.
  • Recommended Workshops






    File Not Exists.