The effect of nitrogen supply sources on the consumption of nicosulfuron poison in the control of fodder corn weeds.

In order to investigate the effect of nitrogen supply sources on the amount of nicosulfuron poison consumption in the spring and summer of 2013 in a farm in Zagheh village of Abik county located in Qazvin province, an experiment was conducted in the form of a split plot experiment in the form of a randomized complete block design with 3 replications. Experimental factors include: sources of nitrogen supply (N1: 100% chemical fertilizer, N2: 25% animal manure + 75% chemical fertilizer and N3: 50% animal manure + 50% chemical fertilizer) as the main factor and herbicide dose at 5 levels (H1: complete weeding, H2: 20, H3: 40, H4: 60 grams of effective substance per hectare and H5: no use herbicide) were as secondary agents. The herbicide application time was 6 to 8 leaves. The results also showed that the effect of nitrogen sources and herbicide dose as well as the interaction effect of the treatments on forage yield were significant. The results of the comparison of the average effect of the levels of nitrogen supply sources and herbicide dose on the forage yield showed that the highest yield belonged to the complete weeding treatment in the condition of 50% animal manure + 50% chemical fertilizer with an average of 58230 kg per hectare, which was placed in a common statistical group with the treatment of 20 grams of effective substance per hectare under the same fertilizer conditions. The results also showed that in the condition of 100% chemical fertilizer, with increasing the dose of nicosulfuron herbicide, fodder yield did not increase significantly. However, in the condition of 50% animal manure + 50% chemical fertilizer, this value decreased with the increase in the consumption dose. Therefore, by using animal manure, the excessive use of herbicides to fight weeds in fodder corn fields can be prevented to a large extent.

Key words: nicosulfuron, fodder corn, cockle crown, animal manure

Introduction

The information available in the field of world food supply shows the worsening of the situation. At least 500 million people of the world population suffer from malnutrition and every 2.5 years the world population increases by 200 million people (Amanlu, 1372). In the meantime, the demand for animal protein sources is increasing rapidly in the world, and every year the need to produce more animal protein sources increases. Fodder plants have a major role in feeding livestock and are classified as one of the most important agricultural plants in the world. However, in most countries of the world, there is little research related to the production and improvement of the quantitative and qualitative characteristics of these plants compared to other crops. In our country, due to the lack of rich pastures and the pressure of livestock on them, it is very important to investigate and study the cultivation of these products (Mirlohi et al., 2009). After wheat and rice, this plant has the highest cultivated area among cereals, and its economic importance is clear to everyone (Anonymous, 2002), because all its parts, including seeds, branches and leaves, and even its cob and stem, are used in human nutrition (20-25%), livestock and poultry nutrition (70-75%), pharmaceuticals and industry (5%). This plant has spread all over the world due to its age and ability to adapt to different climates, and with the efforts of plant breeding specialists, numbers resistant and compatible with different weather conditions have been produced, which has added to this wide cultivation, so that among the corn producing countries, six countries (America, China, Brazil, Mexico, France, Argentina) have 75% of the world's production (Anonymous, 2002). Maize is not native to Iran, but due to the compatibility of the ecological and climatic conditions required for this plant with the climatic conditions of Iran, there is a great potential for the development of its cultivation (Noormohammadi et al., 2008). Weeds not only reduce the amount of available nitrogen in the product, but also the growth of many types of weeds with higher levels of nitrogen (Blackshaw, 2002). Fertilizer application management from the point of view of time, place, amount and type of fertilizer used can be an important tool in the integrated management of weeds (Blackshaw, 2002). In addition, soil nitrogen can affect soil performance and herbicide performance.For example, in low and high soil nitrogen levels, a higher dose of nicosulfuron, glyphosinate, misotrione, and glyphosate herbicides were required to achieve 50% dry weight reduction, which seems to be due to the effect of soil nitrogen on physiological and biochemical processes such as herbicide uptake, transport, and metabolism in weeds (Mithila et al., 2008).

Herbicides can be sufficiently controlled in some conditions with lower than recommended amounts (Kodsk and Stebig, 2003). So far, many efforts have been made to investigate the effect of reduced herbicide rates on weed control in crop fields.

Researchers believe that reducing the yield of crop plants by using Registered herbicides may be due to incorrect and imprecise use, including the use of herbicides at the wrong time or amount, because usually the time of use of many herbicides is stated based on the minimum and maximum number of leaves of the crop plant and weeds, and also with the residue of some post-emergence herbicides in the soil, it does not do much harm, so farmers often delay the use of these herbicides and in order to ensure that most of the weeds are green, in the last opportunity and with larger amounts of herbicides that this type of fight increases the cost and also pollution of the environment (Salzman and Renner, 1992).

Therefore, the purpose of this research was the effect of nitrogen supply sources on the amount of nicosulfuron poison used in the control of fodder corn weeds.

History, origin and origin Corn

Corn with the scientific name of Zeamays is one of the tropical products and the only species that with hundreds of different varieties is included in the genus Zea from the Maydaea family and from the Poaceae family and belongs to monocotyledonous plants. Maize is the only forage that has evolved in Mexico and Guatemala. This plant was not known as a crop plant in the continent of Asia, Europe and Africa until 1492 AD (the year of the discovery of the American continent), but this plant was known centuries ago in Central America and was cultivated by the American Indian people, and for this reason, its Latin name is derived from one of the Indian tribes called Marisi Mahig.

In 1492, two Spaniards who were brought by Christopher Columbus Search and exploration were sent to Cuba and they got to know this plant that the native inhabitants used its flour as food by grinding the seeds. Christopher Columbus called this new plant corn and was the first person to bring it from America to Europe and entered Asia in the 16th century (Tajbakhsh, 1375).

Then, over the years, corn seeds were taken through Portugal to Africa and southern Europe to India and China. After the arrival of corn to the south and west of Europe (16th to 19th centuries AD), it was thought that the origin of this plant is from Asian countries, and for this reason, it was called Turkish wheat, and they believed that corn entered Europe from Asia Minor or Egypt. In 1737, Carl Linnaeus named it Zeamays L. (Karamzadeh, 1368 and Karimi, 1369). a split plot experiment was done as the basis of RCBD in 3 replications. Experimental factors included: nitrogen supply sources (N1: 100% chemical fertilizer, N2: 25% cattle manure + 75% chemical fertilizer, N3: 50% cattle manure + 50% chemical fertilizer) as main plots and herbicide dosage in 5 levels (H1: hand weeding (control), H2: 20, H3: 40, H4: 40 g ai ha-1 and H5: non application of herbicide) as sub plots were considered. Application of herbicide was 6-8 leaves stage. Results showed that the effect of nitrogen sources and herbicide dosage and their interaction were significant on fresh forage yield. Results of interaction of treatments revealed that the highest forage yield belonged to hand weeding under 50% cattle manure + 50% chemical fertilizer that was in a common statistically group with 20 g ai ha-1 herbicide in same fertilizer ratio condition.