Effect of sowing date on phonological stage, morphological characteristics, yield and yield Components of Quinoa (Chenopodium Quinoa L.)

Quinoa is a plant of Amaranthus family, a genus of Chenopodium. Having a wide variety of genetic variations and flexibility allows the plant to adapt to different environments. One of the factors that should be considered when planting a plant in the pattern of cultivation in each region is the planting date of the plant. This factor can affect grain yield and quality by affecting vegetative and reproductive growth period in Quinoa. Sowing date is one of the most effective factors in completing different stages of plant growth. Since observing proper sowing dates will result in higher economic performance without any additional expense and will allow the plant to show its full potential.

In order to study the effect of planting date on phenological, morphological, yield and yield components of Quinoa, a study was conducted on different planting dates on the Quinoa. This study was carried out at a greenhouse complex of Agricultural Jihad in Khalilabad, Khorasan Razavi province, during 2018in a randomized complete block design with three replications and 12 different sowing dates. The cultivation was carried out on March 5 and at intervals of 15 days.

The results showed that the sowing date was significant for the number day of planting to emergence, planting to four leaves, planting to emergence of inflorescence, planting to change the color of inflorescence and planting to harvesting. The results showed that the time from sowing to emergence was reduced by increasing the environment temperature. The results of the experiment showed that the effect of sowing date at 1% probability level was significant on number of seeds per plant, 1000 seed weight, and seed weight per plant, grain yield, biological yield and Harvest Index. The highest grain yield was obtained in sowing date on March 5(2387 kg.ha) and the lowest in sowing date on May 20th (75 kg.ha). The highest biological yield was related to the sowing date of March 5 (10964 kg.ha) and the lowest was related to the sowing date of August 21 (3739 kg.ha), which did not show any significant difference with the sowing date of August 6.

In general, the results showed that different sowing dates due to changes in temperature and day time could affect the morphological, phenological, yield and yield components of the Quinoa under the experimental conditions. The results showed that the flowering stage and seed filling in the Quinoa was one of the sensitive growth stages of the plant to temperature, because the increase in temperature, especially in the flowering and pollination stage, led to a sharp decrease in the number of seeds and, finally, a significant reduction in the grain yield of this plant. In sum, the best sowing date for the Quinoa was obtained based on the information obtained from this study for March 5 and March 21.