Effect of different fertility treatments, foliage harvesting and irrigation on seed-hardness of annual medic (Medicago scutellata cv. Robinson) in a lay farming system in Iran

ABSTRACT: To study the effect of different treatments on seed-hardness of annual medic (Medicago scutellata cv. Robinson) in lay farming system (Medicago scutellata cv. Robinson & Triticum aestivum L.), this experiments has been conducted in Kermanshah province - Iran in 2009 at different fertility systems described as follow; control or without fertilizer (T1), applications of urea (chemical fertilizer) + triple superphosphate fertilizer (T2), urea + phosphate solubilizing bacteria (T3), urea + mycorrhiza fungi (T4), urea + mixture of mycorrhiza fungi and phosphate solubilizing bacteria (T5), nitrogen fixing bacteria + triple superphosphate fertilizer (T6), nitrogen fixing bacteria + phosphorous solubilizing bacteria (T7), nitrogen fixing bacteria + mycorrhiza fungi (T8), nitrogen fixing bacteria + mixture of mycorrhiza fungi and phosphate solubilizing bacteria (T9). Different harvesting management under dryland and irrigation condition in two locations (Dryland Agricultural Research Institute – Sararoud and Soil Fertility Research Station - Mahidsht) were also tested. Annual medic seeds harvested after physiological maturity of pods in July and trend of seed hardness breakdown was evaluated by germination tests in August, September, October, November, December, January, February and March through in vitro conditions. Results showed that the effect of production condition and time lapse on seed hardness breakdown was statistically significant and over eight months since after the physiological maturity of seeds; at the end in both stations about 14% of seed hardness was reduced in both station by aboutby about 14 % of seed hardness in both stations. In dryland conditions, control fertility system (T1) and nitrogen fixing bacteria + mixture of mycorrhiza fungi and phosphate solubilizing bacteria (T9) resulted in the high seed hardness. Otherwise, in irrigation condition, the treatment of urea + mixture of mycorrhiza fungi and phosphate solubilizing bacteria (T5) had the maximum seed hardness. Trend of seed hardness breakdown in foliage harvesting and non-foliage harvesting conditions was not equal, and in equal conditions, percentage of seed hardness in none- foliage harvesting (10.7%) was lower than in foliage harvesting (11.5%). The highest amount of seed hardness breakdown (12.6%) was produced in dry land and foliage harvesting condition.