Evaluation of the possibility of autumn sowing of Plantago major ecotypes in Mashhad climate

Autumn sowing leads to production improvement and yield stability of Plantago major due to the longer growing season, avoid late summer heat stress, and effective use of rainfall. However, in order to succeed in autumn sowing, cold tolerance is essential. It is crucial to carry out plant selection to evaluate and identify top traits for adaptation to environmental factors and ultimately higher production of valuable plants such as broadleaf plantain. Therefore, evaluation of the characteristics of important plants such as broadleaf plantain plays a fundamental role in the selection of top ecotypes for different purposes of selection and increase of yield in different climatic conditions of each region.

This experiment was conducted as split-plot based on randomized complete block design with three replications at Research Farm of Agriculture Faculty of Ferdowsi University of Mashhad (36°15’ N, 56°28’ E, 985 m altitude) during the growing season 2013-14. The experimental factors included six ecotypes of Plantago major (Bojnord, Kalat, Mashhad, Ghaen, Torbat Heydarieh, and Birjand) and four sowing dates (late September, late October, late March, and late April). Irrigation was done immediately after planting and during the growing season according to the need of the farm by furrow method. Survival percentage, spike length, peduncle length, number of capsules, seed in capsule, 1000 grain weight, grain yield, biomass, and harvest index were evaluated. Data analysis was performed in SAS v9.4, and the means were compared by Duncan test at a 95% confidence interval.

The results showed that delay in autumn sowing from September to October reduced the survival percentage in all ecotypes. While, the delay in spring sowing from March to April improved the survival percentage in Birjand, Ghaen, Mashhad and Kalat ecotypes by 12, 8.9, 7.3 and 5%, respectively. The highest percentage of survival in April sowing belonged to Mashhad, Birjand, Ghaen, and Kalat ecotypes and in March sowing belonged to Bojnord ecotype. The highest grain yield (796.9 g m-2) was observed in Ghaen ecotype and the lowest was obtained in Torbat Heydariyeh, Mashhad, and Kalat ecotypes. So that grain yield in Ghaen ecotype was 48, 46, and 59% higher than the mentioned ecotypes, respectively. The highest biomass was observed in September sowing in Bojnord ecotype (2768 g m-2) and the lowest was obtained in April sowing in Kalat ecotype (622 g m-2). Ghaen ecotype had the highest harvest index in all sowing dates. Autumn planting of Plantago major L. leads to reduce in survival percentage compared with the survival percentage of spring planting. Lack of significant difference in grain yield of Plantago major ecotypes in autumn and spring sowing dates indicates the high flexibility of this plant to the date of sowing.

Despite the effectiveness of other factors in the improvement of a plant’s growth, it could be predicted that the Plantago major L. ecotypes that have the ability for establishment in cold conditions are more likely to be in a better position than other ecotypes at other stages of development. Due to the occurrence of heat and drought stresses during the spring growing season and production of suitable biomass for most ecotypes in autumn sowing, the continuation of field and controlled experiments is necessary to evaluate the success of autumn sowing of this plant seems necessary.