هادی میرنعمتی

Medicinal plants play an important role in human health in the world. Many people in different countries of the world tend to use these drugs. Therefore, improve quality of natural medicinal plants is an absolute necessity. Intercropping using time and space, in addition of improving plant production methods in terms of environmental and human health, can increase agricultural production, also. Considering the mentioned issues and the management of weeds in agricultural landscapes, which is one of the biggest problems faced by farmers, this experiment was aim of investigation biochemical characteristics and yield of savory (Satureja hortensis L.) and fenugreek (Trigonella foenum- greacum L.) in intercropping with weeds competition and non- competition conditions.

This experiment was carried out as a split plot in randomized complete block design with three replications in Research Farm of Sari Agricultural Sciences and Natural Resources University in 2016. The treatments of this experiment consisted weeding and no-weeding as the main factor and also, monoculture of savory, monoculture of fenugreek, ratio of 75:25, 50:50 and 25:75% (savory and fenugreek) as sub plots. Dominant weeds were identified as velvetleaf (Abutilon theophrassti Medic.), giant foxtail (Setaria glauca L.), wild melon (Cucumis melo var. agrestis), and bermuda grass (Cynodon dactylon). The studied traits included: shoot fresh and dry weight of savory and fenugreek, photosynthetic pigments (chlorophyll a, b and total chlorophyll), total phenol, total flavonoids, antioxidant activity of them and weeds biomass.

The simple effect of experimental treatments was significant on photosynthetic pigments savory and fenugreek. Phenolic and flavonoid content of leaf and antioxidant capacity for both plants were maximum in 50% savory: 50% fenugreek ratio in weed infestation and showed significant increament in weed infestation compare to weed free. Monoculture of savory showed maximum fresh (1586.67 and 1813.33 g m-2, respectively) and dry (842.33 and 649.20 g m-2, respectively) weight of shoot in weed controlled conditions. The results of the data analysis showed that in all of the three sampling, the highest and lowest biomass of weed species was related to the pure stand of savory and the ratio of 25:75% of savory: fenugreek, and the highest weed biomass was observed in the second stage of sampling.

Overall, the results showed that the intercropping of savory and fenugreek could stabilize the production and betterment biochemical characteristics by improving the use of resources. In addition by decreasing weeds dry weight reduces weed damage and as well as reducing herbicide use, consequently, it is effective for the sustainable production of medicinal plants.