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Abstract A field experiment was carried out in a private farm in Nobaria area during the two successive summer seasons of 1994 and 1995 to investigate the effect of inoculation with Rhizobium sp., calcium application (500 or 750 kg gypsum Fed. -1) with or without foliar Ca and nitrogen fertilization (15, 30 and 45 kg Fed.-l ) and all possible combinations of these treatments on growth, yield and yield attributes of peanut cv. ”Giza 4” and uptake of N, P and K. The obtained results could be summarized as follows: A- Growth: 1. Seed inoculation increased shoot dry weight (SOW), and number of branches (NOB) to different extents during peanut growth while root dry weight (ROW) significantly increased at the early sample (50 days after sowing). 2. Increasing gypsum rate from 500 to 750 kg Fed.-I increased ROWand PH while the other growth characters were reduced, and foliar Ca application generally reduced most of these characters. 3. Increasing N level up to 30 kg Fed. -I caused significant increases in SOW and plant height while RDW was not significantly affected. 4. All possible interactions of Inc., Ca and N caused significant effects on most of the studied growth characteristics. - 67- B- N, P and K uptake: 1. Seed inoculation gave significant increases in the N, P and K uptake by peanut plants during the growth except P at 95. 2. Increasing Ca rate increased N uptake but decreased both P and K uptake. 3. Increasing N rate to 45 kg N Fed.-1 increased Nand K uptake while P uptake was increased by N application up to 30 kg Fed.-1 only. 4. The highest N uptake was recorded by gypsum application at 750 kg Fed.-1 with seed inoculation. 5. P uptake by peanut plants was greatest by the low gypsum rate 500 kg gypsum Fed. -1 with 30 kg N Fed.-1. 6. The highest K uptake was recorded with inoculation combined with gypsum soil application during peanut growth. 7. The inoculation x Ca x N interaction showed that the highest N uptake occurred by seed inoculation combined with the higher gypsum rate (750 kg Fed.-1 ) + foliar Ca and 45 kg N at 50 DAS while this was true by seed inoculation and 750 kg gypsum Fed.-I along with 15 kg N at 95 DAS. However, the uptake of P and K was greater by the lower gypsum rate (500 kg Fed.-1) along with 30-45 kg N without seed inoculation. o- Yield attributes: 1. Yield attribute. i.e. No. of branches, No. of pods and pod weight/plant were positively responded to seed inoculation while seed yield/plant, l00-pod weight and l00-seed weight did not show - 68- significant variations. 2. Seed yield/plant, 100-pod weight and loo-seed weight were increased by increasing gypsum rate while other attributes were decreased. Most yield components were decreased by foliar Ca combined with both gypsum rates. 3. No. of branches and pods/plant were increased by increasing N rate while pod and seed yields/plant as well as loo-pod weight were decreased by increasing N rate to 30 kg Fed. -I and no significant differences between 15 and 45 kg N Fed.-’ were obtained. loo-seed weight was not significantly affected by increasing N rate. 4. Increasing calcium rate under seed inoculation increased pod yield/plant, seed yield/plant weight of 100 pods and weight of 100 seeds, while adverse effects on the same parameters under noninoculation treatment were noticed. 5. No clear trend could be detected with most of yield attributes by increasing N rate under seed inoculation however, significant increases were observed in the absence of seed inoculation. 6. Foliar Ca application showed slight effects on the underground characteristics under N levels, but soil Ca application only along with N application gave positive effects on these underground characteristics. 7. Seed inoculation and application of 15 kg N Fed.-1 along with gypsum application at 500-750 kg improved most yield components. -~-- ---~----~-~-~~~------~--_._---- .~---_ ... - - 69- D- Yield: 1. Seed inoculation significantly increased the yield of pod, straw and oil as well as oil percentage while seed yield was not affected and shelling percentage was reduced. 2. Increasing gypsum rate caused significant increases in seed yield, oil yield and shelling percentage, however additional foliar Ca reduced yields of pods, seeds, straw and oil. 3. Pod yield, seed yield and oil percentage were found to be decreased significantly by increasing N rate up to 30 kg Fed.-t and increased by increasing N rate again to 45 kg Fed:’ may be in part due to the N compensation which was supplied by specific rhizobia which, in turn, is getting inactive by excessive N. 4. Seed inoculation under the higher gypsum rate gave peanut yield approaching that of the lower gypsum rate without inoculation. 5. Seed inoculation combined with 15 kg N Fed.-I recorded the most favourable effects on peanut yield. 6. Application of 500 kg gypsum Fed.-1 combined with the lower N rate (15 kg Fed. -1) achieved greater peanut yield in terms of pod yield, seed yield, straw yield and oil yield compared with the other Ca x N interaction. 7. Seed inoculation combined with 15 kg N Fed.-I under low gypsum rate (500 kg Fed.-I) with foliar Ca gave better peanut yields. |