**4. Conclusion**

Significant particularity of *Echinochloa crus-galli* species is its growing plasticity according to the rising period and the respective climate during the vegetation period. The vegetative phases and vegetative parameters are adjusted so that the plant would completely pass the generative phase and would assure the species perpetuation.

and the regression equation y=2.5148 x + 288.96 shows that every day of seeding delay

The explanation of the identified correlations is found in the climatic characteristics of the experimental years. The dry periods influence negatively the corn germination and rising taking in consideration the spent period from seeding rising, culture density and its homogeneity. The weeds are also influenced less as frequency and more as rising and development period. During the years that are rich in precipitations the weeds succeeded in germination, rising and assurance of a high infestation of the culture. The plus of humidity and temperature from May and June favoured the weeding both as frequency and phonological development especially between May 30 and June 30. The weeds concurrence

The existent weeds mass in the corn crop before harvesting reflects on one side the climatic specific of the agrarian year, but mostly the effectiveness of each applied method to combat

The correlations established between the biomass achieved at harvesting moment of *Ecinochloa crus-galli* and yield (Fig. 4, Fig. 5 and Fig. 6) are – very strong, proving once again the fact that this species is a majoritary one both as frequency in corn crops from Cluj area but also as a corn concurrency potential bringing to significant production reductions. The correlation coefficient (r) is very negative significant having values between 0.861 and 0.952.

1. Weed number/m2 1 0.65\*\* 0.85\*\* 0.92\*\*\* 0.84\*\*\* 2. Covering range, % 1 0.571o 0.90ooo 3. Number of *Echinochloa crus-galli* /m2 1 0.578\* 0.766\*\*\*

days after seeding (mm) 1 0.859\*\*\* 6. Number of days behind seeding 1

The assessment of each combating method both under efficiency in corn crop weeds control aspect and achieved productions level after weeds combating (Fig. 7) it is compulsory and objective. The combating range of *Echinochloa crus-galli* accomplishes with the production a strong positive relation r = 0.959\*\*\*. Therefore, in the case of a 10% increasing of combating

Significant particularity of *Echinochloa crus-galli* species is its growing plasticity according to the rising period and the respective climate during the vegetation period. The vegetative phases and vegetative parameters are adjusted so that the plant would completely pass the

seeding (0C) <sup>1</sup>

Table 11. The existent correlations between the weed characteristics, climatic and

Characteristic 1 2 3 4 5 6

conduce to weed increase with more than 2 weeds/square metre.

to the corn plants in this period it was an acerbic one.

4. Medium rising temperature – 15 days after

5. The amount of precipitations rising - 15

technological conditions from the corn crop.

range, the production rises with 48.65 kg/ha.

generative phase and would assure the species perpetuation.

**4. Conclusion** 

r / p 5% = 0.497; 1% = 0.623; 0.1% = 0.742

the weeds and not lastly the capacity of weeds concurrence.

Fig. 4. The relation between biomass of *Echinochloa crus-galli* and corn yield during the dry years.

Fig. 5. The relation between biomass of *Echinochloa crus-galli* and corn yield during the rainy years.

The problem of the influence of different species of weeds on the production of agricultural plants has been studies by many researchers. The damage caused by weeds in maize crop is mostly of 30-70%, and when the infestation is strong culture can be fully compromised. Our researches highlight in terms of Transylvania, the influence of *Echinochloa crus-galli* species (L.) Pal. Beauv. and other weeds on corn production, according to the degree of infestation. Researches have been conducted at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Romania.

The researches was done on two agrofunds: unfertilized and mineral fertilized with NPK 100 kg s.a./ha. The unfertilized maize crop has been made in four variants with different degrees of infestation of *Echinochloa crus-galli*, from about 40 to 100 plants/m2 and witness – 2 holdings. In fertilized plots were used 4 herbicides for weed control (isoxaflutol 750 g/l; acetoclor 860 g/l; dimetenamid 900 g/l; bentazon 320 g/l + dicamba 90 g/l). Weed biomass, corn plant and grain production was measured in the ripening stage.

Influence of Degree Infestation

period of maize.

**5. References** 

with *Echinochloa crus–galli* Species on Crop Production in Corn 469

considered equal to the weight of green weeds. At a density of 104 plants/m2 of *Echinochloa* 

The prevention of maize crops infestations with weeds and weed control must be adjusted to topoclimate conditions. Along with agro technical, physiomechanical, biological and control means against weeds to share an equal importance for maize crops. All these must be so established as to succeed in efficiently controlling weeding all through the vegetation

In central Transylvania, abundant rainfalls in July, August and even September and high temperatures favours late infestation of maize crops with annual species, very plastic as concerns the springing period and the bio-mass accumulated in the time period, especially *Echinochloa crus-galli.* Thus, when maize is harvested we can observe a high weeding level

The protection of maize crops in the centre of Transylvania against weeds must to be into consideration some factors that are specific for that area. These factors are: large weed seeds reserve in soil, which, every year, provides a high weeding degree of crops; whimsical rainfalls; alternative springing of dominant weed species and their biological specific features, in order to reduce specific maize weeding under the economic deleterious level.

Anghel, G., Chirilă, C., Ciocârlan, V., Ulinici, A. (1972). *The weeds from agricultural cultures* 

Berca, M. (1996). *Actual issues of weeds combating in Romania.The 10th Herbology National* 

Bogdan, I., Gus, P., Rusu, T. (2001). *The green polution – an priority for the Cluj's area* 

Bogdan, I., Gus, P., Rusu, T. (2005). *The vegetative cycle and the productivity characters of the* 

Bogdan, I., Guş, P., Rusu, T., Moraru, P.I., Pop, A.I. (2007). *Research concerning the weeding* 

Bulletin of USAMV-CN, 63-64, p. 283-290. Ed. AcademicPres®, Cluj-Napoca. Bosnic, C. A. and Swanton, C.J. (1997). *Influence of barnyardgrass (Echinochloa crus-galli) time of rising and density on corn (Zea mays).* Weed Science Journal, n. 45, pp. 276-282.

Chirilă, C. (1967). Contributions to knowing the weeds seeds from maize crops*.* Scientific

Clay, S.A., Kleinjan, J., Clay, D.E., Forcella, F., Batchelor, W. (2005). *Growth and fecundity of* 

*several weed species in corn and soybean*. Agronomy Journal, vol. 97, n. 1, pp. 294-302.

of USAMV-CN, 61, p. 405. Ed. AcademicPres®, Cluj-Napoca.

Budoi, Gh. and Penescu, A. (1996). *Agrotehnica*. Ed. Ceres, Bucharest.

Dincă, D. (1957). *Agrotehnica*. Ed. Agrosilvică de Stat, Bucharest.

Dimancea, S.,(1967). *Agrofitotehnica.* Ed. Didactica si Pedagogică, Bucharest.

*agriculture.* The economic increase, development, progress – Scientific communications session –Babes-Bolyai University, Cluj, Romania, XXX, 1703-1713.

*Echinochloa crus-galli (L.) P.B. depending on the rise period, in the Cluj county.* Bulletin

*level of autumn wheat – potato – maize – and soybean crop rotation, in Cluj county.* 

*crus-galli* with green mass of 18,052 kg/ha corn crop is fully compromised.

and the weed seeds reserve accumulating in the soil increases.

*and their combating*. Ed. Ceres, Bucharest.

Bîlteanu, Gh. (2001). *Crop production*. Ed. Ceres, Bucharest.

Berca, M. (2004). *Weeds integrated management*. Ed. Ceres Bucharest.

*Simposium* , Sinaia, p. 7-16.

Papers IANB, Serial A X.

Fig. 6. The relation between biomass of *Echinochloa crus-galli* and corn yield during normal climatic conditions.

Fig. 7. The relation established between the *Echinochloa crus-galli* combating range assured in the tested variants and production level.

Corn invaded by weeds grows anaemic and has a yellowish green colour, in the unfertilized variant the corn develops storied, on the upper *Echinochloa crus-galli* dominates, in the middle floor develops *Setaria glauca* (L.) Beauv. and in the lower floor a number of dicotyledonous. On fertilized variant, the competition between weeds and maize, on the one hand and between monocotyledonous and dicotyledonous on the other hand, is more balanced, as dicotyledonous come from 1,700 kg/ha in mineral fertilized variants, to 4,100 kg/ha in mineral fertilized variant. The amount of weeds, obviously influenced production levels of maize grain and green mass. *Echinochloa crus - galli* had favorable conditions for maize crop infestation; the losses of production are depending on the degree of weed infestation and can reach 5,000 kg/ha maize grain, compared with those obtained in conditions of weeds control. Production losses in terms of green mass per hectare can be considered equal to the weight of green weeds. At a density of 104 plants/m2 of *Echinochloa crus-galli* with green mass of 18,052 kg/ha corn crop is fully compromised.

The prevention of maize crops infestations with weeds and weed control must be adjusted to topoclimate conditions. Along with agro technical, physiomechanical, biological and control means against weeds to share an equal importance for maize crops. All these must be so established as to succeed in efficiently controlling weeding all through the vegetation period of maize.

In central Transylvania, abundant rainfalls in July, August and even September and high temperatures favours late infestation of maize crops with annual species, very plastic as concerns the springing period and the bio-mass accumulated in the time period, especially *Echinochloa crus-galli.* Thus, when maize is harvested we can observe a high weeding level and the weed seeds reserve accumulating in the soil increases.

The protection of maize crops in the centre of Transylvania against weeds must to be into consideration some factors that are specific for that area. These factors are: large weed seeds reserve in soil, which, every year, provides a high weeding degree of crops; whimsical rainfalls; alternative springing of dominant weed species and their biological specific features, in order to reduce specific maize weeding under the economic deleterious level.

#### **5. References**

468 Herbicides – Properties, Synthesis and Control of Weeds

Fig. 6. The relation between biomass of *Echinochloa crus-galli* and corn yield during normal

Fig. 7. The relation established between the *Echinochloa crus-galli* combating range assured in

Corn invaded by weeds grows anaemic and has a yellowish green colour, in the unfertilized variant the corn develops storied, on the upper *Echinochloa crus-galli* dominates, in the middle floor develops *Setaria glauca* (L.) Beauv. and in the lower floor a number of dicotyledonous. On fertilized variant, the competition between weeds and maize, on the one hand and between monocotyledonous and dicotyledonous on the other hand, is more balanced, as dicotyledonous come from 1,700 kg/ha in mineral fertilized variants, to 4,100 kg/ha in mineral fertilized variant. The amount of weeds, obviously influenced production levels of maize grain and green mass. *Echinochloa crus - galli* had favorable conditions for maize crop infestation; the losses of production are depending on the degree of weed infestation and can reach 5,000 kg/ha maize grain, compared with those obtained in conditions of weeds control. Production losses in terms of green mass per hectare can be

climatic conditions.

the tested variants and production level.


Dimancea, S.,(1967). *Agrofitotehnica.* Ed. Didactica si Pedagogică, Bucharest.

Dincă, D. (1957). *Agrotehnica*. Ed. Agrosilvică de Stat, Bucharest.

**25** 

*Lithuania* 

Vytautas Pilipavičius

*Aleksandras Stulginskis University* 

**Herbicides in Winter Wheat of Early Growth** 

Herbicides are chemical substances destroying undesirable plants (weeds) or suppressing

Wheat (*Triticum* spp.) is a cereal that is cultivated worldwide. It is the most important human food grain (Hanee M. Al-Dmoor, 2008). Traditionally, herbicides in winter wheat are applied from two leaf stage till the end of tillering (Triasulphuron - *Logran*) and in spring at tillering (Propoxycarbazone-sodium - *Atribut*, Sulphosulphuron - *Monitor*, Iodosulphuron-methylsodium - *Husar*) and from tillering till booting (Florasulam + 2.4-D 2-ethylhexyl ester - *Mustang*). *Atribut, Monitor and Husar* best fit for control of annual monocotyledonous weeds as *Apera spica-venti, Avena fatua, Poa pratensis* etc. and some annual dicotyledonous weeds as *Galium aparine, Tripleurospermum perforatum, Viola spp., Lamium spp*. etc. *Logran* best fits for control of annual dicotyledonous weeds as *Sinapis spp., Capsella bursa-pastoris, Thlaspi arvense* and etc. while *Mustang* is designed for control of dicotyledonous weeds as *Chenopodium album, Centaurea cyanus, Myosotis arvensis, Sonchus arvensis, Cirsium arvense* and others (Rimavičienė, 2005). Appropriate selected and in time applied herbicides destroy spreading weeds in crop or suppress weed growth and new seed production. Crop weediness is considerably reduced when soil is adequately cultivated, herbicides are applied and crop rotations are practiced (Barberi et al., 1997). It was determined that the field crops of cultured plants are plant associations or so called agrophytocenoses, and that the total biomass of a crop stand (crop and weed biomass) is more or less constant and that the crop yield is inversely proportional to the weed biomass (Lazauskas, 1990, 1993). Effectiveness of chemical weed control is determined by three main specifications: selection of an adequate herbicide, its optimal norm and duration of application. In the process of weed control it should be remembered that wet climate, cold spring weather, long autumn are the factors that help them grow and develop. Another important factor is the ratio of weed biological groups. The prevailing weeds in Lithuania are short-lived annual dicotyledons that comprise 70-90% of all the weeds (Pilipavičius, 2005). Many annual weeds successfully survive till spring because of climate warming; however, they were naturally frozen during winter time just 10-15 years ago. Global warming is the increase in the average temperature of the Earth's near-surface air and the oceans since the mid-twentieth century and its projected continuation. Including uncertainties in future greenhouse gas concentrations and climate sensitivity, the IPCC, scientific intergovernmental body set up by the World Meteorological Organization (WMO) and by the

**1. Introduction** 

their growth.

**Stages Enhance Crop Productivity** 

