A filed experiment was carried out during the two successive seasons of 2016/2017 and 2017/2018 at the experimental farm of El-Gemmeiza, Agric Res. Station, ARC, Gharbiya Governorate (Middle Nile Delta, Egypt) to study the effect of planting date (20 th September (Sep) and 10 th October (Oct), irrigation water level at 50, 75 and 100 % of filed capacity (FC) and two foliar spray with Ca (1%) as calcium chloride and/or boron (60 ppm) as boric acid besides unsprayed treatment (control), and their interactions on yield and its components, tuber cracking and tuber quality under clayey soil conditions using flood irrigation system. The adopted treatments were arranged in a split -split plot design with three replicates. The planting dates were arranged in the main plots, irrigation water quantities were arranged in the sub plots, while Ca and/or B foliar sprays were randomly distributed in sub -sub plots.The obtained results indicate that, the tertiary interaction of planting on 10 th Oct. , irrigation at 100% FC and sprayed plants with Ca + B resulted in higher values of total tuber yield, average tuber weight , number of tuber № plant -1 , tuber yieldplant -1 ,N, K, Ca and B contents and DM percentages in 1 st and 2 nd seasons. Total carbohydrates were the highest with the interaction of planting on 10 th Oct. and irrigating at 100 %FC and sprayed plants with B. The increases in total tuber yield were about 253.75 and 177.82 % for tertiary interaction of planting on 10 th Oct , irrigation at 100% FC and sprayed with Ca + B over the interaction of planting on 20 th Sep , irrigation with 50%FC and unsprayed plants, in the 1 st and 2 nd 38 FAWZY MANSOUR & HANAN ABU EL-FOTOH seasons, respectively. As for tuber cracking %, the lowest values were obtained with the tertiary interaction of planting on 10 th Oct, irrigation with 75 %FC and sprayed with Ca + B (11.37 and 10.41 %) in the 1 st and 2 nd seasons, respectively, while the highest values were obtained with the tertiary interaction of planting on 20 th Sep, irrigation at 100 %FC and without Ca and B (25.38 and 26.57 % in the 1 st and 2 nd seasons, respectively).Conclusively, under similar conditions it could be concluded that , the tertiary interaction of planting on 10 th Oct , irrigation at 100 % FC and sprayed plants with Ca + B was superior for enhancing both total tuber yield and quality. Furthermore, on reducing tuber cracking, combination of planting on 10 th Oct, irrigation at 75% FC and spraying the plants with Ca + B is recommended.

A field experiment was carried at El-Gemmeiza Agric. Res. Station, El-Gharbihya Governorate, Egypt during the two successive summer seasons of 2017 and 2018 to evaluate the effect of green fertilizer (faba bean) and two sources of potassium (mineral potassium sulphate (KS) 48 % K 2 O) or natural feldspar (KF) 10.6 % K 2 O with three levels 50, 75 and 100 % of the recommended rate (RR) beside untreated (control treatment) on growth, yield, sepals chemical constituents and the availability of macronutrients in soil after harvest of Roselle plants (cv. Sabaheia 17) under clay soil conditions. Fourteen treatments were carried out including the combinations of two levels of green fertilizers and six potassium fertilizes, while control treatments contain no fertilizers. A RCBD using a split plot was applied. Results revealed that growth and yield traits of Roselle plants including plant height, number of branches/plant, total dry weight/plant, fruit weight/plant, number of fruit/plant, seed weight/plant, sepals fresh and dry weight per plant and fed. and total yield of seeds/fed., leaf total chlorophyll and carotenoides, anthocyanin concentration, total carbohydrates, total acidity and P percentage in sepals were markedly improved when the green fertilizer combined with fertilizing with 75 % of the recommended Potassium rate (RR) in the form of feldspar (KF) (10.6 % K 2 O) equal 530.65 kg /fed., was applied.The interaction between green fertilizer and fertilizing with 100 % RR in the form of KF possessed the greatest availability of N, P, K, pH and EC in the soil after harvest. K2O at 50 , 75 and 100 % of RR in the form of KS equal 78.12, 117.18 and 156.24 kg/fad, respectively K2O at 50 , 75 and 100 % of RR in the form of KF equal 353.77, 530.65 and 707.54 kg /fad. respectively