Influence of Planting Dates and Nitrogen Fertilization on The Performance of Quinoa Genotypes under Toshka Conditions

TWO FIELD experiments were conducted at South Valley Farm Research Station, Toshka Region, (ARC), Egypt during 2014/2015 and 2015/2016 seasons to study the effect of planting dates (1st Oct. and 1st Nov.) and four N-levels (i.e. 0.0, 50,100,150 kg N /fad) on growth, yield and its components of three quinoa genotypes, (i.e. Kvlsra-2, Regalona and Q-52). Split-split plot design with three replications was used. The results showed that, the effect of planting dates and also N-levels on all the studied traits was significant in both seasons. Increasing N-levels up to 150 kg N/fad significantly increased all traits, while the maximum nitrogen use efficiency (NUE) values were obtained when quinoa received only 50 kg N/fad in the two seasons. Regalona genotype recorded the highest values for all studied traits, while the Q-52 genotype gave the highest values for the nitrogen use efficiency in both seasons. On the other hand, the interaction between planting dates and N-levels had significant effect for all studied traits. However, the interaction between planting dates and genotypes was also significant for all characters except No of inflorescences/plant, weight of 1000 seeds and NUE in the 2014/2015 season, No of branches/plant, dry weight /plant, grain and biological yield in the 2015/2016 season. The interaction between N-levels and genotypes had significant effect on all characters, except No of branches/ plant and grain yield as well as the NUE in the both season. The interactions between planting dates, genotypes and N-levels was significant for the plant height and No of branches /plant in both seasons, dry weight/plant in the first season and weight of seeds/plant and biological yield in the second season. Ash content increased with increasing the N-level. Regalona genotype had the highest value of P, K, Ca and Fe from the obtained results, it could be concluded that planting at 1st Nov., Regalona genotype and treated with 150 kg N/fad had the highest values of seed yield, protein content for planting quinoa under Toshka condition. Results cleared a strong correlation between the yield and its components. Planting quinoa at 1st Nov. using Regalona genotype which fertilized by 150 kg N/fad resulted the highest values of economic evaluation.