Effect of Weed Interference on Yield, Nutritional Value and Some Morphological Characteristics of Alfalfa (Medicago sativa L.)

This research was conducted to evaluate the effect of weed interference and non-interference in different densities of alfalfa on yield, nutritional value and some morphological traits of alfalfa as a forage crop. 

The experiment was performed as factorial and based on a randomized complete block design with three replications in two cuttings during 2018-2019 crop years. The experimental treatments were weed interference and non-interference in two levels (hand weeding and non-hand weeding) and plant density in four levels (20, 40, 60 and 80 stems per square meter). 

Weeds identified in this Alfalfa field included: Carthamus tinctorius, Centaurea cyanus, Ceratocephalus falcatus, Convolvulus arvensis, Cuscuta sp., Cynodon dactylon, Descurainia sophia, Euphorbia maculate, Poa bulbous, Hordeum morinim, Lactuca scariola, Rumex acetosella, Salvia sclarea, Sisymbrium irio, Sorghum halepense, Taraxacum officinalis, Tragopogon graminifolius, Vaccaria hispanica. The results of each harvest in the third year of established alfalfa showed that the presence of weeds caused a decrease in the quantity and quality of alfalfa forage plant. 

The results obtained in two cuttings in the third year of established alfalfa showed that the weeds caused quantitative and qualitative reduction in alfalfa. Alfalfa in the second cutting had better growth compared to the first cutting, so that the plant produced the highest fresh and dry yield in the second cutting. Weed non-interference increased the levels of superior morphological traits of alfalfa, such as fresh and dry yield, plant height, and number of leaves per plant, number of main-stem nodes, leaf area and percentage of vegetation cover as well as increased the nutritional value of alfalfa in terms of nutrient elements, proteins and factors such as ADF, Ash, CF, NDF.