Application of herbicides on common winter wheat (Triticum aestivum L.) at different doses and their reflection on the structural elements of spike

  1. Z. Petrova, Nankova

 

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

 

DOI: 10.15547/ast.2018.03.046

(Manuscript received 13 June 2018; accepted for publication 25 July 2018)

 

Abstract. The aim of this investigation was to determine the effect of the application dose of herbicides on structural elements of spike in common winter wheat (Triticum aestivum L.). The investigations were carried out during 2015–2017 at Dobrudzha Agricultural Institute (DAI) – town of General Toshevo. The following herbicides were used: Derby super WG (33 g/ha; 66 g/ha; 132 g/ha), Secator ОD (100 mL/ha; 200 mL/ha; 400 mL/ha), Ergon WG (50 g/ha; 100 g/ha; 200 g/ha), Granstar super 50SG (40 g/ha; 80 g/ha; 160 g/ha), Lintur 70WG (150 g/ha; 300 g/ha; 600 g/ha) and Mustang 306.25 СК (800 mL/ha; 1600 mL/ha; 3200 mL/ha) from the group of sulfunylureas with various mechanism of action. The preparations were applied at three doses – optimal, double and quadruple, at stage 29 of common winter wheat cultivar Dragana, Zlatitsa and Kalina. The herbicide effect was determined by the quantitative weight method and evaluated by the EWRS scale. These were the traced structural elements of the wheat spike: length of spike (cm), number of spikelets per spike, number of grains per spike, weight of grain per spike (g) and weight of 1000 grains (g). Four-factor dispersion analysis was applied. The factors year conditions, cultivar, herbicide and dose were traced. The factors with the highest strength of effect were the year conditions (10-95%) and the used cultivar (2-87%). Significantly lower was the effect of the factors applied herbicide (2-4%) and dose (1-2%) on the investigated structural elements of spike.

 

Effect of the herbicide treatment dose on the weed infestation in common winter wheat

Z. Petrova*

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria
(Manuscript received 10 June 2017; accepted for publication 24 October 2017)

Abstract. The aim of this investigation was to determine the effect of the treatment dose of herbicides on the weed infestation in common winter wheat. The investigations were carried out during 2015 –2016 at Dobrudzha Agricultural Institute (DAI) – General Toshevo. The following herbicides were used: Derby super WG (33 g/ha; 66 g/ha; 132 g/ha), Secator ОD (100 ml/ha; 200 ml/ha; 400 ml/ha), Ergon WG (50 g/ha; 100 g/ha; 200 g/ha), Granstar super 50SG (40 g/ha; 80 g/ha; 160 g/ha), Lintur 70WG (150 g/ha; 300 g/ha; 600 g/ha) and Mustang 306.25 СК (800 ml/ha; 1600 ml/ha; 3200 ml/ha) from the group of sulfunylureas with various mechanism of action. The preparations were applied at three doses – optimal, double and quadruple, at stage 29 (according to Zadoks et al., 1974) of common winter wheat cultivars Dragana, Zlatitsa and Kalina. The herbicide effect was determined by the quantitative weight method and evaluated by the EWRS scale. Regardless of the used dose and the cultivar, Derby super WG, Secator OD, Lintur 70WG and Mustang 306.25СК had highest efficiency (100%) against the following investigated weeds: Sinapis arvensis L., Matricaria chamomilla L., Anthemis arvensis L., Galium tricorne (Stock.), Consolida orientalis (J. Gay) and Cirsium arvensis L. Ergon WG and Granstar super 50SG had 100% efficiency against Sinapis arvensis L., Matricaria chamomilla L. and Anthemis arvensis L. and lower effect (90-94%) on Galium tricorne (Stock), Consolida orientalis (J. Gay) and Cirsium arvensis L.

Changes in the leaf gas exchange of common winter wheat depending on the date of application of a set of herbicides

Z. Petrova1*, Z. Zlatev2

1Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria
2Department of Plant Physiology, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

Abstract. The aim of this investigation was to determine the effect of the date of application of a set of herbicides on the foliar gas exchange of common winter wheat. The investigations were carried out in 2013 and 2014 at Dobrudzha Agricultural Institute (DAI). The following herbicides were used: Derby super VG (33 g/ha), Granstar 75DF (15 g/ha), Lintur 70VG (150 g/ha), Secator ОD (100 ml/ha), Mustang 306.25 СК (800 ml/ha), Palace 75WG+oil (250+1000 g/ml/ha) and Husar Мax ОD (1000 ml/ha) from the group of suflonylureas with various mechanism of action. The preparations were applied at two stages of common winter wheat cultivars Aglika and Enola (stages 29 and 32 according to Zadoks). The indices of leaf gas exchange were followed: rate of net photosynthesis (А), intensity of transpiration (E), stomatal conductivity (gs) and intercellular concentration of СО2 (ci). It was found that the later application (stage 32) of Lintur 70VG and Mustang 306.25СК caused visible signs of phytotoxicity. These were expressed as anthocyanin pigmentation of leaves and spikes and as partial to full sterility of spikes, stronger after using Lintur VG and weaker after Mustang 306.25СК. Following a delayed application of the herbicides, slower rate of growth of plants was observed, as well as disturbances in the parameters of foliar gas exchange. The high rate of A at comparatively low E and gs and the low ci in the weeded check indicated that the plants spent considerable energy resources to overcome the negative effect of weeding.

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Productivity and stability of the yield from common winter wheat cultivars developed at IPGR Sadovo under the conditions of Dobrudzha region

P. Chamurliyski1*, E. Penchev1, N. Tsenov2

1Dobrudzha Agricultural Institute, 9521 General Toshevo, Bulgaria 2Agronom I Holding, 9300 Dobrich, Bulgaria

Abstract. One of the main directions of the common winter wheat breeding programs in Bulgaria is related to enhancing productivity. Since wheat is a crop of the microclimate, yield is strongly influenced by the conditions of the environment. The contemporary tendencies in the breeding of this crop are directed not only towards achieving high results with regard to productivity but also towards maintaining a relative stability of yield under changeable climatic factors. The aim of this investigation was to study the productivity and determine the stability of the yield from common winter wheat cultivars developed at the Institute for Plant and Genetic Resources (IPGR) Sadovo under the conditions of Dobrudzha region, Bulgaria. The field experiment was carried out in the trial field of Dobrudzha Agricultural Institute (DAI) during 2011 – 2013. Nineteen cultivars, breeding of IPGR, were tested in three replications. Cultivar Enola was used as a standard. The productive potential, the elements of yield and its stability were investigated. Two-factor dispersion, variation and correlation analyses were applied for statistical evaluation of the results, and the method of Kang, PCA analysis and AMMI models were involved to describe stability. With regard to vegetation period, the investigated materials did not differ from the standard cultivar Enola. They possessed typical good combination of high tillering capacity and grain weight per spike. The productivity of the studied accessions was formed mainly by these two indices. The cultivars, which realized highest yields averaged for the tree years of the investigation, were Mustang, Diamant, Tsarevets and Geya 1, and cultivars Bononya, Momchil and Lusil demonstrated stability by this trait. The optimal ratio between high productive potential and yield stability was observed in cultivars Mustang, Tsarevets, Momchil and Boryana.

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