- Email: [email protected]
Aspects of Winter Wheat Physiology Treated with Herbicides
Available online at www.sciencedirect.com
ScienceDirect Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
“ST26733”, International Conference "Agriculture for Life, Life for Agriculture"
Aspects of Winter Wheat Physiology Treated with Herbicides Nicolae IONESCUa, Aurelian PENESCUb* b
a Agricultural Research and Development Station Piteúti, 5 Piteúti-Slatina Road, 117030, Piteúti, Romania University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Marasti Blvd, 011464, Bucarest-1, Romania
Abstract Environment agriculture: crop plants, weeds and soil can occur by applying enough strict rules of chemical treatment. These are: the correct dosages, time intervals, implementing optimal correlation unwanted flora and plants phenophase development. Wheat proceed too easy to broadening the range of herbicides, from different causes. Applying too early (even in autumn) and late- as often happens in practice, produce change normal physiology of wheat plants. From recent research (Pascal & Scala, 1999), showed that herbicide metabolism pathway can induce negative phenomena, expressed in particular by modifying of winter wheat plant, fruit, grain. This is the case of hormonal herbicides applied late (bout stage) and again bromoxynil (PS II inhibitor) in the autumn to the emergence of the first tiller. The data highlight the very obvious loss of production for hormons and relative for bromoxynil.
© Published by Published Elsevier B.V. This is an open access article under the CC BY-NC-ND license © 2015 2015 The Authors. by Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest. Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest Keywords: hormonal herbicides: 2,4-D, dicamba, fluroxypyr, PS II inhibitors: bromoxynil.
1. Introduction As well as in other crop plants, wheat has herbicide application in order to avoid the specific weed flora. This is done in the integrated management of weeds- IWM and today it is considered as very useful. With the application of active substances- herbicides in wheat crop, there are a number of phenomena considered as complex, both favorable and unfavorable. In these circumstances wheat grower will make the herbicide of specialty recommendations. At the same time will take into account the restrictions that exist, for example, treatment application in spring when wheat
* Corresponding author. Tel.: +4021-318-2564; Fax: +4021-318-2888. E-mail address: [email protected]
2210-7843 © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest doi:10.1016/j.aaspro.2015.08.037
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
is in the process of twinning and weeds are sprung, monitor consumption solution whose concentration is the correct, application of the entire cultivated area etc. In terms of metabolic and physiological wheat any herbicide to be applied does not cause any phytotoxic phenomena, due to the presence of a large group of substances which converts herbicides molecules in non-toxic metabolites. The group does not work as the weeds and they soon perish (died). This substances are belonging to the group type of the enzyme like glutathione-S-transferases (GST)(Cummings et al., 1997; Edwards et al., 1996, 1997). Their role is to detoxify electriphilic type herbicides arriving in wheat plants. GST mode of action is to catalyze the conjugation of herbicides with glutathione molecule (gamma-glutamyl-cysteinyl-glycine). Glutathione is a major cellular thiol that glutathione- dependent enzymes with roles in buffering performs detoxification, and as redox reactions. Detoxification of herbicides in wheat plants occur with glutathione conjugation, by the specific reaction. Within their sequence were replaced by other non-toxic induce toxic reactions, which takes place after the processing and disposal of the herbicide. Among the classes that belong to the GST (phi-F class, the theta- class T, U tau- class, and class zeta-Z), and in wheat prevailed tau class (eg. TaGSTU2) (Pascal et al., 1998). After detoxification of herbicide, residues occurs exports remaining outside the cell metabolism. First debris will in the cell vacuole (Coleman et al., 1997). Type glutathion conjugates enter in the processing reactions initiated by hydrolysis of glycine residue and namely a specific vacuolar carboxypeptidase. Dipeptide conjugate can be re-exported from the vacuole into the cytoplasm (cytoplasmic solution) and is associated with the group moving by gamma- glutamyl- transpeptidase. Derivates of type S-cystenyl can follow a variety of subsequent transformations, including N-malonylation and subsequent degradation to a wide range of polar metabolites, some of which are residues of herbicides, and can be incorporated into natural products as mature grains (Koeppe et al., 1998; Tal et al., 1993). Many herbicides are following the path of glutathione in their metabolism and detoxification race in crop plants. From research carried out over the years has found that some herbicides applied to wheat undergoes changes and can induce physiological disorders, resulting in real losses of grain. It’s about applying herbicides at times improper, unsuitable and unfortunately are taking place today on farms. This research has some deviation from the normal physiology of wheat plants with an emphasis on the production of grain formation, by applying herbicides to combat weeds at times, be located before the optimum time, or after it. 2. Materials and Methods In the 2010-2013, there were applied specific herbicides to winter wheat in two separate groups as physiology, characterized by two modes of action (MA). Thus, the first group of synthetic hormons were used: 2,4-D acid, dicamba and fluroxypyr. For the second group, acting against photosnthesis, photosystem II- step (PS II) was herbicide bromoxynil. The herbicides were applied to wheat, the scheduled time, and the existence of tillering plants and rosette stage of weeds (Table 1). Table 1. Herbicides utilized for wheat physiology study. Place of action
Herbicides
Chemical class
Action of auxins to the protein binding, like indolyl acetic acid, IAA
2.4-D acid Dicamba
Phenoxy- carboxylic acids Benzoic acid
Fluroxypyr
Pyridine- carboxylic acids
Photosystem II
Bromoxynil
Nitriles
This calendar takes place in April. In comparison with the normal state, treatments have been inappropriate times, or late stage bellows hormone herbicides, or very early onset of the first tiller in the fall PS II inhibitor, bromoxynil, in order to observe possible occurrence of certain physiological abnormalities. Wheat was cultivated normally recommended after resort technology, in bifactorial experience, the type of parcel subdivision design. A factor was the moments of application of herbicides and factor B treatment as such, all the doses recommended for production. The experimental variants were each 25 m2 in four repetitions. In the mature stage were sampled and analyzes were performed grain morphology: the number of grains per ear, grain weight per
53
54
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
ear and a one thousand grain weight (TGW). The average values of the first two determinations were developed specific correlations. The statistical calculation we used analysis of variance, ANOVA test, and Excel program. 3. Results and Discussions Influence of herbicides in the two groups on the physiological action of wheat plants was different and characteristic. How wheat plants responded, in particular by applying the recommended times, it revealed abnormal physiology. 3.1. Wheat physiology by hormones From the historical point of view, hormones were first discovered and used for weed control (2.4-D and dicamba in the 50s-60s). Initially it was found the natural auxins act as stimulation at very low doses, similar indolyl acetic acid (IAA). By increasing their doses of hundreds and even thousand of times found to become toxic herbicidal (kills plants). In addition, natural auxins have been factory, so that the doses used for synthetic products have become commercial herbicides. From physiologically synthetic auxins, hormones in their action herbicidal auxin signal perception interrupt natural or artificial inducing signals. The consequence subsequent occurrence of side effects, including localized abnormal growth, for example the twisting of leaves, stems, shoots curvature, the vertical bending on the ground and their droppings etc. Their target instead of auxin action is in the chain (synthesis) of proteins. Inhibited multiple physiological processes are not yet fully known. Products on the market are still very effective and therefore their use is found below. However, with such an improper operation of the physiology of wheat can be adversely affected. The optimum phase used in the experiment of hormones (BBCH 29) did not affect the normal physiology of the wheat plant, so that the correlation between the number and weight of grains derived from one ear were positive and very high correlation coefficients of more than 0.9, i.e. close to the ideal situation (Figure 1). 2.4-D acid applied at a late phenophase to the bout stage, showed a smaller scattering of the data, compared with the control. The correlation coefficient r = 0.915 close control is r = 0.927. In the figure the difference values regression approach shows a scattering relative to the bellows herbicides. Physiology wheat expressed by the correlation between the number and weight of the grain was not clear if this affected the herbicide. Dicamba product shows that it negatively affected skin physiology wheat. Distribution of wheat grains shows a scatter evident. The graph shows that the grains are formed under these conditions the mass (weight) less. In practice this means loss of production. The correlation coefficient obtained at this stage was 0.603 bellows to control, r = 0.907. If there was a hormonal herbicide currently it is no disruption of normal physiology of wheat. Lighter grains were formed in the ears average grain content of 20 to 30. The third product to create the same negative fluroxypyr, an an apparent coefficient r = 0.811, compared to control (r = 0.963). Lighter grains are formed in the ears with the grain 10 30. A special situation created by combining two- hormonal herbicides 2.4-D and dicamba (Figure 2). Physiology of wheat and especially deposition of nutrients in grains was the most affected. Reduced number of grains and grain weight, located generally below 0.6 g, mostly close to 0. This means that if the grain has a grain size, they were filled, the blank. With mechanical hervesting such crop affected by herbicide will not produce normal seeds, and production will be close to zero. In this case wheat physiology was greatly affected. 3.2. Wheat physiology by bromoxynil, a PS II inhibitor Lately practice becoming more herbicides in autumn, given the favorable evolution of wheat crop this season with something warm background. Bromoxynil product has the capacity to control weeds because of its specific action mode. Place the target protein is the QB (or D1) and is physiologically inhibited photosynthetic electron carrier. Thus, in the process of photosynthesis, the light phase, there is a group of the accessory components, which together form the second system. They are also light energy fixers. They fixed energy is then transferred to chlorophyll issuing energized electrons needed to form ATP and carbohydrates. Their representative in PS II (photosystem II) complex is the protein- chlorophyll a, which are interdependent. Herbicide bromoxynil blocks energizing electrons and thus impedes the transmission, transportation through two phenomena: their binding QB protein (D1) and by blocking the electron carrier mobility, i.e. specific plastaquinone.
55
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
2.4-D tillering period
2 1 0 0
0 20 40 Number graind per ear
60
Grains weight/ear, g
Fluroxypyr tillering period
3
y = 0.0467x - 0.1529 r = 0.963
2 1 0 0
20 40 Number grains per ear
0 0
Grains weight/ear, g
Grains weight/ear, g
1
0
1
60
20 40 Number grains per ear
60
Dicamba bout stage
3
y = 0.0467x - 0.2439 r = 0.907
2
y = 0.0494x + 0.0029 r = 0.915
2
60
Dicamba tillering period
3
Grains weight/ear, g
20 40 Number grains per ear
2.4-D bout stage
3
y = 0.0557x - 0.2235 r = 0.927
Grains weight/ear, g
Grains weight/ear, g
3
y = 0.0462x - 0.2866 r = 0.603
2 1 0 0
20 40 Number grains per ear
60
Fluroxypyr bout stage
3
y = 0.0448x - 0.2993 r = 0.811
2 1 0 0
20
40
60
-1 Number grains per ear
Grains weight/ear, g
Fig. 1. Correlations between no of grains and their weight, grams/ear, in average wheat spikes after auxin- binding protein herbicide 2.4-D acid, dicamba, fluroxypyr application in delayed phenophases- bout stage.
2.4-D+ dicamba bout stage
2
y = 0.0089x - 0.0585 r = 0.442
1
0 0
20 40 Number grains per ear
60
Fig. 2. Correlation between no of grains and their weight, grams/ear, in average wheat spikes after auxin- binding protein herbicide 2.4-D acid with dicamba, application in delayed phenophases- bout stage.
56
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
The fall, early tillering at the beginning of application of herbicide (BBCH 21), resulted in a relative grainnegative influence on the physiology (Figure 3). Scattering data in the two graphs is relatively comparable with the observation that the treatment of autumn grain weight was significantly lower. Instead it was observed that mature ears look has changed, taking the form of the curve, possibly due to the combination with the herbicide 2.4-D acid. The wheat plants and grains were negative influenced (Figure 4). 3.3. Aspects average measurements performed on ear of wheat
Bromoxynil + 2.4-D, autumn, I tiller, BBCH 21
4
y = 0.0453x - 0.3159 r = 0.930
3 2 1 0 0
50 100 Number of grains per ear
Grains weight/ear, g
Grains weight/ear, g
From the presented graphs showed negative influence, and different feature two classes of herbicides with specific physiological action. Analysis of grain ears and thus demonstrated to what extent could have affected the normal physiology of wheat (Table 2). The number of grains decreased significantly in case of hormons, most of which occured in the combination 2.4-D with dicamba: 20.3 grains/ear witness to 40.7 grains/ear. A spike grain weight decreased significantly reduced for all herbicides, which noted the same combination of hormons 2.4-D + dicamba. One thousand grain weight was significantly reduced in all treatments except 2.4-D acid. Bromoxynil + 2.4-D, spring, 2-3 tillers, BBCH 29
4
y = 0.0524x - 0.3973 r = 0.924
3 2 1 0 0
50 100 Number of grains per ear
Fig. 3. Correlations between no of grains and their weight, grams/ear, in average wheat spikes after bromoxynil application in early phenophase- 1st tiller.
Fig. 4. The effect of bromoxynyl, autumn application, on ears and grains. Table 2. The influence of herbicides moments application on wheat grain formation. The treatment
Number grains per ear
Grains weight/ ear, g
Thousand grains weight, TGW, g
Check 2.4-D acid dicamba fluroxypyr 2.4-D+ dicamba 2.4-D+ bromoxynil LSD 5 % LSD 1 % LSD 0.1%
40.7 36.9 0 26.5 000 21.9 000 20.3 000 39.2 2.84 4.01 5.72
1.81 1.43 000 0.94 000 0.68 000 0.12 000 1.53 00 0.16 g 0.23 g 0.32 g
48.5 47.4 35.5 000 31.1 000 5.9 000 37.5 000 4.0 g 5.6 g 8.1 g
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
4. Conclusions Wheat herbicides constitute an important economic in integrated weed management (IWM). Applying herbicides in weed presence resumption twin spring vegetation protects wheat plant physiology. In practice, the use of both herbicides late and at the very early, both negative influence on wheat. Of the two groups of herbicides, hormons are dangerous and less the PS II inhibitors By applying the bellows- phase herbicide 2.4-D in the ear of the affect grain weight and the number average of grain from the ear, while the remaining close control of the TGW. Dicamba alone and in combination with 2.4-D and fluroxypyr very obviously affected all three determinations. By applying this fall, the first phase of wheat tiller, bromoxynil TGW significantly affected very significantly in the ear and grain weight did not affect the number of grains in the aer. Physiology research of this kind may be important in promoting the new rules of the IWM by chemical means, yet very important economically. References Cole, D.J., 1994. Detoxification and activation of agrochemicals in plants. Pesticide Science, 40, 209-222. Coleman, J.O.D., Blakeka, L.F.F., Davies, T.G.E., 1997. Detoxification of xenobiotics by plants: chemical modification and vacuolar compartimentation. Trends in Plant Science, 2, 144-151. Cummins, J., Cole, D.J., Edwards, R., 1997. Purification of multiple glutathione transferases involved in herbicide detoxification from wheat (Triticum eastivum L.) treated with the safener fenclorazole- ethyl. Pesticide Biochemistry and Physiology, 59, 35-49. Edwards, R., Cole, D.J., 1996. Glutathione transferases in wheat (Triticum) species with activity towards fenoxaprop- ethyl and other herbicides. Pesticide Biochemistry and Physiology, 54, 96-104. Edwards, R., 1997. Glutathione transferases and herbicide metabolism and selectivity. Weed and Crop Resistance to Herbicide, Kluwer Academic, Dordrecht, 109-115. Koeppe, M.K., Barefoot, A.C., Cotterman, C.D., Zimmerman, W.T., Leep, D.C., 1998. Basis of selectivity of the herbicide flupyrsulfuronmethyl in wheat. Pesticide Biochemistry and Physiology, 59, 105-117. Pascal, S., Debrauwer, L., Ferte, M.P., Anglade, P., Rouimi, P., Scalla, R., 1998. Analysis and characterisation of glutathione S-transferases subunits from wheat (Triticum aestivum L.). Plant Science, 134, 217- 26. Pascal, S., Scalla, R., 1999. Purification and characterisation of a safener- induced glutathione S-transferase from wheat (Triticum aestivum). Physiologia Plantarum, 106, 17-27. Tal, A., Romano, M.L., Stephenson, G.R., Schwan, A.L., Hall, J.C., 1993. Glutathione conjugation- a detoxification pathway for fenoxapropethyl in barley, crabgrass, oat and wheat. Pesticide Biochemistry and Physiology, 46, 190-199.
57
ScienceDirect Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
“ST26733”, International Conference "Agriculture for Life, Life for Agriculture"
Aspects of Winter Wheat Physiology Treated with Herbicides Nicolae IONESCUa, Aurelian PENESCUb* b
a Agricultural Research and Development Station Piteúti, 5 Piteúti-Slatina Road, 117030, Piteúti, Romania University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Marasti Blvd, 011464, Bucarest-1, Romania
Abstract Environment agriculture: crop plants, weeds and soil can occur by applying enough strict rules of chemical treatment. These are: the correct dosages, time intervals, implementing optimal correlation unwanted flora and plants phenophase development. Wheat proceed too easy to broadening the range of herbicides, from different causes. Applying too early (even in autumn) and late- as often happens in practice, produce change normal physiology of wheat plants. From recent research (Pascal & Scala, 1999), showed that herbicide metabolism pathway can induce negative phenomena, expressed in particular by modifying of winter wheat plant, fruit, grain. This is the case of hormonal herbicides applied late (bout stage) and again bromoxynil (PS II inhibitor) in the autumn to the emergence of the first tiller. The data highlight the very obvious loss of production for hormons and relative for bromoxynil.
© Published by Published Elsevier B.V. This is an open access article under the CC BY-NC-ND license © 2015 2015 The Authors. by Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest. Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest Keywords: hormonal herbicides: 2,4-D, dicamba, fluroxypyr, PS II inhibitors: bromoxynil.
1. Introduction As well as in other crop plants, wheat has herbicide application in order to avoid the specific weed flora. This is done in the integrated management of weeds- IWM and today it is considered as very useful. With the application of active substances- herbicides in wheat crop, there are a number of phenomena considered as complex, both favorable and unfavorable. In these circumstances wheat grower will make the herbicide of specialty recommendations. At the same time will take into account the restrictions that exist, for example, treatment application in spring when wheat
* Corresponding author. Tel.: +4021-318-2564; Fax: +4021-318-2888. E-mail address: [email protected]
2210-7843 © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the University of Agronomic Sciences and Veterinary Medicine Bucharest doi:10.1016/j.aaspro.2015.08.037
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
is in the process of twinning and weeds are sprung, monitor consumption solution whose concentration is the correct, application of the entire cultivated area etc. In terms of metabolic and physiological wheat any herbicide to be applied does not cause any phytotoxic phenomena, due to the presence of a large group of substances which converts herbicides molecules in non-toxic metabolites. The group does not work as the weeds and they soon perish (died). This substances are belonging to the group type of the enzyme like glutathione-S-transferases (GST)(Cummings et al., 1997; Edwards et al., 1996, 1997). Their role is to detoxify electriphilic type herbicides arriving in wheat plants. GST mode of action is to catalyze the conjugation of herbicides with glutathione molecule (gamma-glutamyl-cysteinyl-glycine). Glutathione is a major cellular thiol that glutathione- dependent enzymes with roles in buffering performs detoxification, and as redox reactions. Detoxification of herbicides in wheat plants occur with glutathione conjugation, by the specific reaction. Within their sequence were replaced by other non-toxic induce toxic reactions, which takes place after the processing and disposal of the herbicide. Among the classes that belong to the GST (phi-F class, the theta- class T, U tau- class, and class zeta-Z), and in wheat prevailed tau class (eg. TaGSTU2) (Pascal et al., 1998). After detoxification of herbicide, residues occurs exports remaining outside the cell metabolism. First debris will in the cell vacuole (Coleman et al., 1997). Type glutathion conjugates enter in the processing reactions initiated by hydrolysis of glycine residue and namely a specific vacuolar carboxypeptidase. Dipeptide conjugate can be re-exported from the vacuole into the cytoplasm (cytoplasmic solution) and is associated with the group moving by gamma- glutamyl- transpeptidase. Derivates of type S-cystenyl can follow a variety of subsequent transformations, including N-malonylation and subsequent degradation to a wide range of polar metabolites, some of which are residues of herbicides, and can be incorporated into natural products as mature grains (Koeppe et al., 1998; Tal et al., 1993). Many herbicides are following the path of glutathione in their metabolism and detoxification race in crop plants. From research carried out over the years has found that some herbicides applied to wheat undergoes changes and can induce physiological disorders, resulting in real losses of grain. It’s about applying herbicides at times improper, unsuitable and unfortunately are taking place today on farms. This research has some deviation from the normal physiology of wheat plants with an emphasis on the production of grain formation, by applying herbicides to combat weeds at times, be located before the optimum time, or after it. 2. Materials and Methods In the 2010-2013, there were applied specific herbicides to winter wheat in two separate groups as physiology, characterized by two modes of action (MA). Thus, the first group of synthetic hormons were used: 2,4-D acid, dicamba and fluroxypyr. For the second group, acting against photosnthesis, photosystem II- step (PS II) was herbicide bromoxynil. The herbicides were applied to wheat, the scheduled time, and the existence of tillering plants and rosette stage of weeds (Table 1). Table 1. Herbicides utilized for wheat physiology study. Place of action
Herbicides
Chemical class
Action of auxins to the protein binding, like indolyl acetic acid, IAA
2.4-D acid Dicamba
Phenoxy- carboxylic acids Benzoic acid
Fluroxypyr
Pyridine- carboxylic acids
Photosystem II
Bromoxynil
Nitriles
This calendar takes place in April. In comparison with the normal state, treatments have been inappropriate times, or late stage bellows hormone herbicides, or very early onset of the first tiller in the fall PS II inhibitor, bromoxynil, in order to observe possible occurrence of certain physiological abnormalities. Wheat was cultivated normally recommended after resort technology, in bifactorial experience, the type of parcel subdivision design. A factor was the moments of application of herbicides and factor B treatment as such, all the doses recommended for production. The experimental variants were each 25 m2 in four repetitions. In the mature stage were sampled and analyzes were performed grain morphology: the number of grains per ear, grain weight per
53
54
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
ear and a one thousand grain weight (TGW). The average values of the first two determinations were developed specific correlations. The statistical calculation we used analysis of variance, ANOVA test, and Excel program. 3. Results and Discussions Influence of herbicides in the two groups on the physiological action of wheat plants was different and characteristic. How wheat plants responded, in particular by applying the recommended times, it revealed abnormal physiology. 3.1. Wheat physiology by hormones From the historical point of view, hormones were first discovered and used for weed control (2.4-D and dicamba in the 50s-60s). Initially it was found the natural auxins act as stimulation at very low doses, similar indolyl acetic acid (IAA). By increasing their doses of hundreds and even thousand of times found to become toxic herbicidal (kills plants). In addition, natural auxins have been factory, so that the doses used for synthetic products have become commercial herbicides. From physiologically synthetic auxins, hormones in their action herbicidal auxin signal perception interrupt natural or artificial inducing signals. The consequence subsequent occurrence of side effects, including localized abnormal growth, for example the twisting of leaves, stems, shoots curvature, the vertical bending on the ground and their droppings etc. Their target instead of auxin action is in the chain (synthesis) of proteins. Inhibited multiple physiological processes are not yet fully known. Products on the market are still very effective and therefore their use is found below. However, with such an improper operation of the physiology of wheat can be adversely affected. The optimum phase used in the experiment of hormones (BBCH 29) did not affect the normal physiology of the wheat plant, so that the correlation between the number and weight of grains derived from one ear were positive and very high correlation coefficients of more than 0.9, i.e. close to the ideal situation (Figure 1). 2.4-D acid applied at a late phenophase to the bout stage, showed a smaller scattering of the data, compared with the control. The correlation coefficient r = 0.915 close control is r = 0.927. In the figure the difference values regression approach shows a scattering relative to the bellows herbicides. Physiology wheat expressed by the correlation between the number and weight of the grain was not clear if this affected the herbicide. Dicamba product shows that it negatively affected skin physiology wheat. Distribution of wheat grains shows a scatter evident. The graph shows that the grains are formed under these conditions the mass (weight) less. In practice this means loss of production. The correlation coefficient obtained at this stage was 0.603 bellows to control, r = 0.907. If there was a hormonal herbicide currently it is no disruption of normal physiology of wheat. Lighter grains were formed in the ears average grain content of 20 to 30. The third product to create the same negative fluroxypyr, an an apparent coefficient r = 0.811, compared to control (r = 0.963). Lighter grains are formed in the ears with the grain 10 30. A special situation created by combining two- hormonal herbicides 2.4-D and dicamba (Figure 2). Physiology of wheat and especially deposition of nutrients in grains was the most affected. Reduced number of grains and grain weight, located generally below 0.6 g, mostly close to 0. This means that if the grain has a grain size, they were filled, the blank. With mechanical hervesting such crop affected by herbicide will not produce normal seeds, and production will be close to zero. In this case wheat physiology was greatly affected. 3.2. Wheat physiology by bromoxynil, a PS II inhibitor Lately practice becoming more herbicides in autumn, given the favorable evolution of wheat crop this season with something warm background. Bromoxynil product has the capacity to control weeds because of its specific action mode. Place the target protein is the QB (or D1) and is physiologically inhibited photosynthetic electron carrier. Thus, in the process of photosynthesis, the light phase, there is a group of the accessory components, which together form the second system. They are also light energy fixers. They fixed energy is then transferred to chlorophyll issuing energized electrons needed to form ATP and carbohydrates. Their representative in PS II (photosystem II) complex is the protein- chlorophyll a, which are interdependent. Herbicide bromoxynil blocks energizing electrons and thus impedes the transmission, transportation through two phenomena: their binding QB protein (D1) and by blocking the electron carrier mobility, i.e. specific plastaquinone.
55
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
2.4-D tillering period
2 1 0 0
0 20 40 Number graind per ear
60
Grains weight/ear, g
Fluroxypyr tillering period
3
y = 0.0467x - 0.1529 r = 0.963
2 1 0 0
20 40 Number grains per ear
0 0
Grains weight/ear, g
Grains weight/ear, g
1
0
1
60
20 40 Number grains per ear
60
Dicamba bout stage
3
y = 0.0467x - 0.2439 r = 0.907
2
y = 0.0494x + 0.0029 r = 0.915
2
60
Dicamba tillering period
3
Grains weight/ear, g
20 40 Number grains per ear
2.4-D bout stage
3
y = 0.0557x - 0.2235 r = 0.927
Grains weight/ear, g
Grains weight/ear, g
3
y = 0.0462x - 0.2866 r = 0.603
2 1 0 0
20 40 Number grains per ear
60
Fluroxypyr bout stage
3
y = 0.0448x - 0.2993 r = 0.811
2 1 0 0
20
40
60
-1 Number grains per ear
Grains weight/ear, g
Fig. 1. Correlations between no of grains and their weight, grams/ear, in average wheat spikes after auxin- binding protein herbicide 2.4-D acid, dicamba, fluroxypyr application in delayed phenophases- bout stage.
2.4-D+ dicamba bout stage
2
y = 0.0089x - 0.0585 r = 0.442
1
0 0
20 40 Number grains per ear
60
Fig. 2. Correlation between no of grains and their weight, grams/ear, in average wheat spikes after auxin- binding protein herbicide 2.4-D acid with dicamba, application in delayed phenophases- bout stage.
56
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
The fall, early tillering at the beginning of application of herbicide (BBCH 21), resulted in a relative grainnegative influence on the physiology (Figure 3). Scattering data in the two graphs is relatively comparable with the observation that the treatment of autumn grain weight was significantly lower. Instead it was observed that mature ears look has changed, taking the form of the curve, possibly due to the combination with the herbicide 2.4-D acid. The wheat plants and grains were negative influenced (Figure 4). 3.3. Aspects average measurements performed on ear of wheat
Bromoxynil + 2.4-D, autumn, I tiller, BBCH 21
4
y = 0.0453x - 0.3159 r = 0.930
3 2 1 0 0
50 100 Number of grains per ear
Grains weight/ear, g
Grains weight/ear, g
From the presented graphs showed negative influence, and different feature two classes of herbicides with specific physiological action. Analysis of grain ears and thus demonstrated to what extent could have affected the normal physiology of wheat (Table 2). The number of grains decreased significantly in case of hormons, most of which occured in the combination 2.4-D with dicamba: 20.3 grains/ear witness to 40.7 grains/ear. A spike grain weight decreased significantly reduced for all herbicides, which noted the same combination of hormons 2.4-D + dicamba. One thousand grain weight was significantly reduced in all treatments except 2.4-D acid. Bromoxynil + 2.4-D, spring, 2-3 tillers, BBCH 29
4
y = 0.0524x - 0.3973 r = 0.924
3 2 1 0 0
50 100 Number of grains per ear
Fig. 3. Correlations between no of grains and their weight, grams/ear, in average wheat spikes after bromoxynil application in early phenophase- 1st tiller.
Fig. 4. The effect of bromoxynyl, autumn application, on ears and grains. Table 2. The influence of herbicides moments application on wheat grain formation. The treatment
Number grains per ear
Grains weight/ ear, g
Thousand grains weight, TGW, g
Check 2.4-D acid dicamba fluroxypyr 2.4-D+ dicamba 2.4-D+ bromoxynil LSD 5 % LSD 1 % LSD 0.1%
40.7 36.9 0 26.5 000 21.9 000 20.3 000 39.2 2.84 4.01 5.72
1.81 1.43 000 0.94 000 0.68 000 0.12 000 1.53 00 0.16 g 0.23 g 0.32 g
48.5 47.4 35.5 000 31.1 000 5.9 000 37.5 000 4.0 g 5.6 g 8.1 g
Nicolae Ionescu and Aurelian Penescu / Agriculture and Agricultural Science Procedia 6 (2015) 52 – 57
4. Conclusions Wheat herbicides constitute an important economic in integrated weed management (IWM). Applying herbicides in weed presence resumption twin spring vegetation protects wheat plant physiology. In practice, the use of both herbicides late and at the very early, both negative influence on wheat. Of the two groups of herbicides, hormons are dangerous and less the PS II inhibitors By applying the bellows- phase herbicide 2.4-D in the ear of the affect grain weight and the number average of grain from the ear, while the remaining close control of the TGW. Dicamba alone and in combination with 2.4-D and fluroxypyr very obviously affected all three determinations. By applying this fall, the first phase of wheat tiller, bromoxynil TGW significantly affected very significantly in the ear and grain weight did not affect the number of grains in the aer. Physiology research of this kind may be important in promoting the new rules of the IWM by chemical means, yet very important economically. References Cole, D.J., 1994. Detoxification and activation of agrochemicals in plants. Pesticide Science, 40, 209-222. Coleman, J.O.D., Blakeka, L.F.F., Davies, T.G.E., 1997. Detoxification of xenobiotics by plants: chemical modification and vacuolar compartimentation. Trends in Plant Science, 2, 144-151. Cummins, J., Cole, D.J., Edwards, R., 1997. Purification of multiple glutathione transferases involved in herbicide detoxification from wheat (Triticum eastivum L.) treated with the safener fenclorazole- ethyl. Pesticide Biochemistry and Physiology, 59, 35-49. Edwards, R., Cole, D.J., 1996. Glutathione transferases in wheat (Triticum) species with activity towards fenoxaprop- ethyl and other herbicides. Pesticide Biochemistry and Physiology, 54, 96-104. Edwards, R., 1997. Glutathione transferases and herbicide metabolism and selectivity. Weed and Crop Resistance to Herbicide, Kluwer Academic, Dordrecht, 109-115. Koeppe, M.K., Barefoot, A.C., Cotterman, C.D., Zimmerman, W.T., Leep, D.C., 1998. Basis of selectivity of the herbicide flupyrsulfuronmethyl in wheat. Pesticide Biochemistry and Physiology, 59, 105-117. Pascal, S., Debrauwer, L., Ferte, M.P., Anglade, P., Rouimi, P., Scalla, R., 1998. Analysis and characterisation of glutathione S-transferases subunits from wheat (Triticum aestivum L.). Plant Science, 134, 217- 26. Pascal, S., Scalla, R., 1999. Purification and characterisation of a safener- induced glutathione S-transferase from wheat (Triticum aestivum). Physiologia Plantarum, 106, 17-27. Tal, A., Romano, M.L., Stephenson, G.R., Schwan, A.L., Hall, J.C., 1993. Glutathione conjugation- a detoxification pathway for fenoxapropethyl in barley, crabgrass, oat and wheat. Pesticide Biochemistry and Physiology, 46, 190-199.
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