عنوان مقاله [English]
Sustainable agriculture refers to the correct management of agricultural resources that, while meeting changing human needs, preserves the quality of the environment and the capacity of water and soil resources. Among the components of sustainable agriculture, we can mention the agroforestry system, integrated pest management, crop rotation and intercropping. The purpose of intercropping is to find plants that have the least competition with each other and use the available resources more effectively. The purpose of this research is the effect of intercropping of Roselle on the quantitative and qualitative traits of borage under foliar application of iron fertilizer, and to determine the best ratio of intercropping to achieve the highest yield and the highest level of land equivalent ratio.
Material and Methods
This research was carried out in the educational-research farm of the Faculty of Agriculture of Zabol University, in the agricultural year of 2014-2015. The experiment was carried out as a factorial in the form of a randomized complete block design with three replications. The treatments examined in this research include foliar spraying of sulfate fertilizer as the first factor in three levels including |(no foliar application or control, 3gr.l-1 and 6gr.l-1) and eight levels of intercropping including (pure Roselle, pure Borage, 75% Roselle + 25% Borage, 75% Borage + 25% Roselle, 50% Roselle + 50% Borage, 50% Roselle + 100% Borage, 100% Roselle + 50% Borage, 100% Roselle + 100% Borage were as the second factor. Both plants were planted at the same time at the end of March in 2×2 plots, where the distance between the planting lines was 50 cm, the distance between the rows was the same, but the density was different in each row. Irrigation was done according to the needs of the plants, weeding and thinning during the growth period and weeding was done by hand during three stages. Wagner's method was used to measure the amount of anthocyanins. The criterion for evaluating intercropping was using land equivalent ratio. At the end, data analysis will be done using SAS version 9.1 software and comparison of means will be done using Duncan's test at the 5 % level.
Results and Discussion
Results showed that interaction effects of foliar application, iron and intercropping were significant on anthocyanin and mucilage of borage. In addition, results showed that the simple effects of foliar application Iron were significant on Number of flowers per stem, stem height, Number of sub-branches, Biological yield and Harvest index. The effects of intercropping were significant on number of flowers per stem, anthocyanin, mucilage, stem height, number of sub-branches, economical yield and harvest index. The comparison of means effects of different intercropping systems showed that the highest biological yield (1412.8 kg.ha-1) was obtain from the intercropping system of 75% Roselle + 25% borage. In addition, the comparison of means effects of different intercropping systems showed that the highest amount of economic yield (49.68 kg.ha-1) was obtain from the treatment of pure borage cultivation. Comparison of means showed that the highest percentage of mucilage with an average of 0.0713% from the foliar treatment of 6gr.l-1 of iron sulfate in the conditions of pure borage cultivation and the lowest percentage of mucilage was obtained with an average of 0.0280 from the control treatment (no application of iron sulfate fertilizer + 100% Roselle + 50% borage). The highest land equivalent ratio (2) was obtain from intercropping of 100% Roselle + 50% borage harvest
According to the results obtained in the present study, the effects of foliar application of iron and intercropping systems had significant effects on yield and yield components of borage. By increase in foliar application of iron, it improved growth traits and yield. The highest proportion of LER obtained was from 100% Roselle+ 50% borage, which indicated superior, cropping, compared to pure crop. This superiority is probably due to the better use of mixed components of growth resources such as light, water and nutrients compared to pure crop.