Soil Cover Effects on Yield and Some Physiological Characteristics of Marigold (Calendula officinalis L.) under Methanol Foliar Application

This study was conducted to assay the effects of methanol foliar application (0, 10, 20 and 30% v/v) and bed cover (control, white and black covers) on yield and some physiological traits of marigold as a factorial based on RCBD. The results revealed the significant interaction effects of bed cover and methanol foliar application on chlorophyll a content and plant height. The highest plant height was belonged to black mulch × methanol (except for 30% methanol). The highest chlorophyll a content (2.3 mg g-1 FW) was attained by black mulch × 30% methanol. Chlorophyll b content was influenced by soil cover and the highest chlorophyll b content (1.1 mg g-1 FW) was recorded with black mulch. The flowers and leaves dry weight as well as relative water content and total soluble solids content were affected by the treatments and, the highest data for flower dry weight (116 g) was in 30% foliar spray and black mulch (103.6 g). The highest data for total soluble solids content (120 °Brix) and relative water content (49.7%) were recorded with 30% methanol foliar application and by black soil cover. For root-dry weight (15.3 g) and total phenolics content (95.05 mg GA g-1 Dwt), black mulch was the treatment of choice.