Effects of Sowing Date, Planting Pattern and Nitrogen Levels on Leaf and Flower Essential Oil, Yield and Component Yield Grain of Buckwheat (Fagopyroum esculentum Moench)

IntroductionBuckwheat which has been scientifically named Fagopyrum esculentum can be considered as a yearling broad-leaved plant belonging to the family of Polygonaceae which is known as false Cereal. Its seeds are in use as a nutritional and medicinal product that is due to the rutin content of them. As the population is rapidly increasing worldwide, a solution must be found to supply necessary food. What agriculture science is responsible for is to produce more products with better quality in order to meet this increasing population’s needs so that food poverty and starvation are more likely to be removed and keep food safety. Considering the fact that buckwheat is of a variety of medical, industrial and food applications and in our country and some other ones, it has not been seriously cultivated, this plant must be used as a new plant and it should be extensively applied in multiple planting systems (summer planting) for commercial goals through producing seeds while its nutritional value is more than grain and it can be regarded as a rich source of high quality protein, amino acid necessary for lysine, high starch percent, minerals and vitamins for different applications involving cake flour, frumenty and soup and improving the optimal rate of rutin as a secondary metabolite having effective medical features concerning our country’s climatic conditions.
Materials and MethodsIn order to investigate the effects of sowing date, planting patterns and nitrogen on leaf and flower rutin, yield and yield component of Buckwheat plant, a field study was conducted during 2010 and 2011 in Agricultural Research Institute of Arak, Iran. The experimental design was regarded as the randomized complete block design in the form of split plot factorial with three replications. Planting treatments as the fundamental elements may be implemented at two levels including the mounds with the width of 50 cm associated with two planting rows regarding the distance intervals of 20 cm (P1) and those with the width of 60 cm along with three planting rows which are of the distance intervals of 15 cm (P2). Sowing date and nitrogen treatments were considered as the minor elements are likely to be studied at four levels of dates and weights involving 20th June (D1), 5th July (D2), 20th July (D3) and 5th August (D4) and 0 (N1), 50 (N2), 100 (N3) and 150 kg ha-1 (N4), respectively. With respect to the fixed density of 100 plants per square meter, the distances between the planting lines were specified as four and five cm for treatments of P1 and P2, respectively. Dimensions of each plot for the planting patterns of P1 and P2 have been determined as 1.6×2 and 1.6×2.4 m consisting of four planting rows.
Results and DiscussionResults showed that the interaction effects of sowing date×planting pattern × nitrogen were significant on grain yield and 1000- grain weight (p≤0.05). the number of seeds in plant, leaf and flower rutin percent also were significant (p≤0.01). But, number of bunch in the plant were non significantly. Maximum grain yield with 2857 kgha-1, 1000- grain weight (29.28 g), and number of the seeds in the plant 434.1 was observed P2D3N3. The highest of number of bunch in the plant with 33.20 was produced P2D2N3. Maximum leaf rutin percent with 1.01 was observed to P2D2N4 treatment also highest flower rutin percent (1.36%) observed to P1D3N3 treatment. The lowest rates of grain yield as 1074 kg ha-1, 1000- grain weight as (23.96 g), number of bunch in the plant (11.72), number of seeds (60.18), leaf rutin (0.14%) and flower rutin (0.30%) have been found for the treatments of P1D3N1, P2D4N2, P2D4N2, P1D4N2, P2D2N1, P2D3N2.
ConclusionsIf application of this plant is just for grain consumption, the treatment P2D3N3 to produce active substances as a medicinal plant should be considered. For the extraction rutin leaves P2D4N4 treatment and flower P1D3N3 treatment is suitable for extraction rutin.