Effect of Fenugreek (Trigonella foenum-graecum L.) and Black Seed (Nigella sativa L.) Additive Intercropping on Yield and Yield Components

Medicinal plants are looked upon not only as a source of affordable health care products but also as a source of income. There is a growing demand for plant-based medicines, health products, essential oils, fragrances, cosmetics and natural aroma chemicals in the markets. Cultivation of medicinal and aromatic plants has several advantages such as higher net returns per unit area, low incidence of pests and diseases, improvement of degraded and marginal soils, longer shelf life of end products and foreign exchange earning potential. Intercropping is a multiple cropping system that has been practiced for many years in various methods in most of the regions. It has played important roles in the redistribution of soil nutritional resources and establishment of soil microbial diversity. Legumes have been intercropped with medicinal plants for many years. Land equivalent ratio (LER) is often used as an indicator to determine the efficiency of intercropping. It is the most common index adopted in intercropping to measure the land productivity. The objectives of this study were to determine the effects of black seed (Nigella sativa L.) intercropped with fenugreek (Trigonella foenum-graecum L.) in additive series on their yield and yield components and LER.
 

An experiment was performed based on a randomized complete block design with six treatments and three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during growing season of 2015-2016. Intercropping ratios were 25% B (black seed) +100% fenugreek (F), 50% B+100% F, 75% B +100% F, 100% B+100% F and their monoculture. Studied traits were the number of branches per plant, the number of follicles per plant, the number of seeds per follicle, 1000- seed weight, seed yield, biological yield and harvest index for black seed and the number of branches per plant, the number of pods per plant, the number of seeds per pod, 1000- seed weight, seed yield, biological yield and harvest index for fenugreek. LER was calculated as the criterion for intercropping.
The treatments were run as an analysis of variance (ANOVA) by using Minitab to determine if significant differences existed among treatments means. Multiple comparison tests were conducted for significant effects using the LSD test.
 

The results showed that the different intercropping ratios of black seed with fenugreek had significant effect on the number of branches per plant, the number of follicles and pods per plant, the number of seeds per follicle/pod, seed yield and biological yield. The highest and the lowest seed yield of black seed were observed for monoculture and 25% black seed+100% fenugreek with 291 and 107 kg.ha-1, respectively. The maximum and the minimum seed yield of fenugreek were related to its monoculture and 100% black seed+100% fenugreek with 655 and 363 kg.ha-1, respectively. When the two plants are grown together, yield advantages occur due to their differences to use resources.
LER of the black seed/ fenugreek intercropping system ranged from 1.12 to 1.24, and thus land use efficiency was significantly enhanced by this intercropping system. LER was much higher than one in all of the intercropping ratios, indicating the intercropping yield advantage. The maximum LER was calculated for 75% black seed+100% fenugreek with 1.24.
 

Fenugreek intercropped with black seed showed a significant increase in yield, yield components and LER. It has been proved that the effects of intercropping by its involvement in improved soil chemical characteristics, increased nitrogen content (nitrogen biological fixation) has greatly contributed to agroecological services. It can be concluded that intercropping of fenugreek with contributed to productivity increases per unit area of black seed.
Acknowledgement
This research was funded by Vice Chancellor for Research of Ferdowsi University of Mashhad, which is hereby acknowledged.