Effect of Iron and Zinc Foliar Application and Plant Spacing on Productivity of Oil Lettuce (Lactuca scariola var. Oleifra) in Calcareous Soils تاثير الرش الورقى بالحديد والزنک ومسافات الزراعة على انتاجية خس الزيت بالأراضى الجيرية

Field trials were carried out during 2016/17 and 2017/18 growing seasons at Mariout Experimental Station, Desert Research Center, Egypt, to investigate the effect of foliar application with iron and zinc (control, 150 mg iron /L, 100 mg zinc /L and 150 mg iron + 100 mg zinc /L) and different plant distances (10, 20 and 30 cm between plants) on growth, yield and yield components as well as oil content of prickly oil lettuce under calcareous soil conditions. The experimental design was a split plot, whereas the main plots involved iron and zinc treatments and the sup main plots involved plant distances. The obtained results cleared that iron and zinc foliar application significantly affected on all traits, except number of branches/plant and harvest index, also plant spacing significantly affected on all traits, except plant height and 1000-seed weight during the two seasons, respectively. The interaction between iron and zinc foliar application and plant spacing had significant effects on all traits as an average for both seasons. Foliar application of iron and zinc together as a combination treatment caused an increase in all yield traits as compared with untreated plants in both seasons. Increasing the distance between plants from 10 to 20 and/or 30 cm significantly decreased seed yield/fad and seed yield/plant in both seasons. Oil percentage was increased when plants were transplanted at 20 cm a part. However, the oil yield was gradually decreased by increasing the distance between plants up to 30 cm. In general oil lettuce plants which treated by150 mg iron + 100 mg zinc /L and transplanted at 10 cm a part produced the highest values of seed and oil yield.