THE EFFECT OF FERTILIZATION AND REPEATED MOWING ON SOME VEGETATIVE CHARACTERISTICS AND YIELD OF PANICUM MOMBASA PLANT

: The experiment was perfumed according to (R.C.B.D) in triplet in field belongs to the department of crop sciences, college of Agricultre, university of Diyala, whose soil has a texture of Slity loam during spring season of 2019, to study the effect of addition of three different types of fertilizers to the soil which are Humic acid 300 kg.h -1 , Trichoderma 75 kg.h -1 and NPK 200 Kg.h -1 , on the growth and characters of Panicum Maximum cv Mombasa. Results showed significant superiority of humic acid fertilizer after 40 days of fertilization with regards to the plant height, branches number, leaves number, leaf area, the total yield of green feed and hay yield. In fertilization treatment with tricoderma, the weed after 40 days was outstanding in the characters of the plant height, branches number, leaves number, leaf area, the total yield of green feed and hay yield, treatment with NPK, the cut after 40 days exceeded in the plant height, branches number, leaves number, leaf area, the total yield of green feed and the hay yield.

Trichoderma fungus is one of the fungi deficient in living throw, which is used in the field of biological control Biocontrol, and works to increase the readiness of some elements, such as nitrogen, phosphorus and potassium through the secretion of some enzymes, and its ability to decompose organic materials present or added to the soil, and contribute to the production of growth regulators and increase The ability of plants to resist unfavorable environmental conditions, thus improving the nutritional status of the plant and increasing the plant growth [3]. [4] showed that when adding humic acid, it has clear effects on the vegetative growth of the plant. In addition, it leads to an increase in the activity of the photosynthesis process and the index of leaf area. [5] stated that the addition of trichoderma caused a significant increase in plant lengths. Wheat and dry weight of shoots. This study aims to search for scientific alternatives to leave the chemical fertilizers polluting the environment by knowing the response of the Panicum fodder crop to the organic and biological fertilizers added to its soil and identifying the appropriate duration of the mower, as well as breeding and improving the Panicum crop to fill the deficiency in the quantitative and qualitative yield of forage.

Materials and Methods
A field experiment was carried out on the panicum crop in the spring season 2019 in the fields of the Field Crops Department / College of Agriculture -University of Diyala, with the aim of studying the response of the panicum mombasa plant to fertilization and the extension of weeds under the drip irrigation system. Random samples were taken from different areas of the field's soil for the purpose of laboratory analysis, at a depth of 0-30 cm before the cultivation process was carried out to determine some chemical and physical characteristics of the study soil, as shown in Table (1). A global experiment (fertilizer factor, mulching time factor) was applied according to the Randomized Complete Block Design (R.C.B.D) system and broadcast three replicates, and the area of one experimental unit was 4.5 m 2 (1.5 m x 3 m), in lines, the distance between one line and another is 50 cm and between one Jura and another. 50 cm and a plant density of 40,000 plants.h -1 . A distance of 1 m is left between one repeater and another and between an experimental unit and another to avoid interactions between transactions, such as transferring fertilizers during irrigation.
Panicum seedlings were planted 17 days old and 15 cm long in the sustainable field after irrigating the soil of the experiment on 3/23/2019 and were planted in the field soil and watered regularly until their roots are well fixed in the soil, while continuing to fight the bush manually whenever needed until the arrival Plant height to 1 m.
After confirming the readiness of the planted seedlings to receive fertilizers, on 4/8/2019, the experiment parameters (fertilizers) were added to the experimental units, and the transactions were distributed randomly, as the fertilizers included NPK fertilizer of 200 kg.h -1 , and humic fertilizer by 300 kg.h -1 and Trichoderma fertilizer of 75 kg. H -1 , and a hole was made in the soil with a depth of 5 cm along the planting lines and for all the experimental units and covered with soil in order to preserve fertilizers from the sun's rays. Fertilize the field soil.
These mills were manually carried out at a height of 5 cm above the soil level. The number of sheets. plant -1 : It was calculated as an average of the number of leaves of seven plants and for the same plants for which the number of branches were measured [7].
Leaves area (cm 2 ): The leaves area was measured according to the following equation: leaves area (cm 2 ) = leaf length x maximum sheet width x 0.75 [8].
leaves area index (cm 2 ): The leaves area index was calculated according to the following equation [9]: Total yield of green forage (tons. h -1 ) = average yield per plant of green fodder (gm) x plant density in hectares [10].
The hay yield (tons. h -1 ): -After calculating the dry weight of one plant (gm), the hay yield (tons. h -1 ) was calculated through the following equation: Hay yield (tons. h -1 ) = average dry weight per plant (g) x plant density in hectares. [10].
Statistical analysis: Statistical analysis of the data was performed using the Duncan test as a global experiment within the Randomized Complete Block Design (R.C.B.D) in order to compare the averages of the studied transactions under the probability level of 0.05 [11] and using the SAS program [12].

Results and Discussion
Plant height (     The reason for this is that humic acid is one of the stimulating and stimulating factors for the growth and reproduction of microorganisms that secrete organic acids and stimulating hormones such as auxins and gibberellins that stimulate the growth and elongation of stem cells and increase plant height [13]. Number of branches (branch. Plant -1 ): The results in Fig. 4     The reason for this is that the addition of humic acid has a significant effect on the emergence and growth of roots and the increase in their length, which leads to an increase in the absorption of macro and micro nutrients [14]. Number of leaves (leaf. Plant -1 ): Figure (7) shows the presence of significant differences in the charac-        While figure (12) showed that there were no significant differences between the averages after 40 days of  The reason for this is that humic acid increases the permeability of cell membranes, and thus increases the process of absorption of nutrients and water, as humic acid increases the readiness of macronutrients and micronutrients, especially nitrogen, phosphorous and potassium that affect many vital processes that contributed to increasing the length and width the leaf that affected the increase in leaf area, as well as the humic acid increases the surface area of soil particles [15].
Leaf area index: Table (4) shows that there were no significant differences between the averages for the index characteristic of leaf area of plants after 20 days of fertilization. Also, Table (2) showed the presence of significant differences between the averages after 30 days of fertilization. Humic fertilizer outperformed the rest of the fertilizers and recorded the highest average for this characteristic as it reached 18.30, with an increase of 20.95% compared to the control treatment. Fertilization with Trichoderma and NPK scored an average of 16.56 and 16.33 for leaf area index, respectively, compared to the control treatment, which recorded the lowest average of 15.13.
While Table (2) indicates that there is a significant difference between the averages for the average characteristic of the index of leaf area, after 40 days of fertilization, the humic fertilization treatment recorded the highest average for the studied characteristic, with an average of 22.91 and an increase of 17.00% compared to the control treatment. While fertilization with NPK and Trichoderma recorded the mean for the index leaf area was 22.14 and 21.50, respectively, compared to the control treatment, which recorded the lowest average of 19.58.
The reason for this may be attributed to the fact that humic acid has the ability to improve the chemical, biological and physical properties of the soil and when it decomposes it gives carbonic acid, which is a weak acid that decomposes into ions (H + ) and ions (Hco3 -), and this contributes to changing the soil pH. It also helps in dissolving some of the insoluble mineral substances, which are not accessible to the plant, such as phosphorous, magnesium, potassium and calcium, as it increases the readiness of the trace elements due to the low pH of the soil solution so that they are easily absorbed by the plant [16].
Total green fodder yield (tons. H -1 ):  While the results of Table (3) indicated that there were no significant differences between the averages of fertilization treatments for the total yield characteristic of green fodder, after 40 days of fertilization. This may be due to an increase in the rates of photosynthesis and food manufacturing processes, due to the positive effect of humic acid on plants [17].
Green yield (tons. h -1 ): Table ( h -1 , respectively, compared to the control treatment, which recorded the lowest average of 8.47 tons. h -1 . Table (4) shows that there were significant differences between some averages, after 30 days of fertilization, humic fertilizer was significantly superior to the rest of the fertilizers, as it recorded the highest average for this characteristic of 15.47 tons. h -1 , with an increase of 25.67% over the control treatment, While the fertilization with Trichoderma and NPK recorded an average of 12.92 and 12.68 tons. h -1 , respectively, compared to the control treatment, which recorded the lowest average of 12.31 tons. h -1 .