Investigation of the effect of planting date and density on quinoa in saline and rainfed conditions

All over the world, there are high salinity lands and most of those considered as an arid or useless lands (from agriculture aspect) for lack of knowledge about resistant varieties. Quinoa plant indicate significant resistance to wide range of Abiotic stress such as salinity and cold. Also this plant is protein-rich and can be a good alternative to rice and wheat. It is necessary to study about this kind of plants in the critical condition (saline soil & dry farming) more than ever. In this paper we investigate about the impact of date of planting and density in dry farming and saline soil on quinoa plant yield.

In this study, the experiment, split plot design in completely randomized block base format with three repetition in the crop year 2019 (1397- 98) was performed in one of the farms of Gomishan city, Golestan province. Main factor consists of three planting date (February 4, March 6, April 4) and subsidiary factor has three density (60, 80, 100 and 120 plants per m^2). To determine the length of growth stages and dry weight and doing analysis, Sampling was done once in every two weeks. Final yield is determined by split middle line. during the growth season the important dates of plant phenology such as time for emergence & seedling development, physiological maturity, flowering and grain development divided by different treatment notes were taken. lastly, data obtained were analyzed by statistical software SAS and average data evaluated by LSD test.

The results indicate significant impact of planting date on plant height, number of seeds per panicle, dry weight of the plant and weight of one thousand seeds significance 1 percent level and weight of panicle, number of seeds of branch were at significance 5 percent level. Maximum values of this functional traits was obtained in planting date february 4. and planting date March 6 has the lowest values of these traits. plant height, number of seeds per panicle, wet and dry weight of the plant significantly affected by density factor. all interactions of both factor had huge impact on measured traits. most yields in 60 and 80 density plants per m^2 were significantly more than this trait's value in other planting density. results of this study indicate that february 4 was the best quinoa planting date (in comparison to other reviewed planting dates) for Gomishan and its condition, also 80 density plants per m^2 (high density without any decreased yield) is the most suitable for there.

Due to the quinoa high resistance to drought and salt stress as well as appropriate performance, as a strategic product could be recommended to farmers. by the results of this paper we can conclude that february 4 is the best planting date for saline soil and dry farming. delay to cultivation has a significant decrease in reviewed traits. moreover, because 80 density plants per m^2 increased the plant yield in most traits, then it could be considered as a most appropriate density to this study condition. however to confirm this findings it is necessary to check this experiment another year.