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Abstract 5-SUMMARY AND CONCLUSSIONS This study was carried out at Quwesna Agricultural Mechanization Station to develop a front mounted mower (Prototype) and also to improve the rear mounted mowers widely utilized in Egyptian argiculture. During 1986. a prototype of front mounted mower was developed. then in 1988-1989 a conveying belt for imporving the performance of rear mounted mowers was designed and tested. The front -mounted mower (Prototype) and the conveyor for rear mounted mower were developed in order to overcome some harvesting problems that usually Occure when either self-propelled mower or tractor rear~ounted ones are used resp. Both of the improved equipement were tested and evaluate4 comparing with the other of mowers under actual field conditions during 1987- 1989. The selected field crops tor mowing trials were wheat and cotton . The developed mowers were constructed and attached to a 30 Hp agriCUltural tractor (kOUbot~. For the front mounted mower (prototype ) the source of power was taken from the front p.t.o of the koubota tractor through bevel gears to transmit the power from the crankshaft to the connecting rod of a single knife mower. 78 A nor.mal single knife bar of 127 cm wide with its sides and connections (as normally used in self propelled machines) was adapted and reassembled to be mounted on a specially made frontal hydrQulic hitching. The selected differential system was of speed ratio of ~bout 5 : 1. In winter of 1988. a rear ~ounted mower was improved by designing a conveyor consisting of a wide belt (100 x 150 cm) moving on two drums ( 7.5 cm diam. and 100 cm length). The conveyor was attached to the mower frame and it ,r.. took its drive power from the crank~shaft of mower through two transmission gears giving a speed reduction of 3 1 (4cm 12 cm diameteres), . The designed linear speed for the conveyor was 118 m/min. at 500 r.p.m. of the p.t.o. and 4.2 km/h. tractor forward-speed. This conveying system served to overcome the main disadvantages of the rear~ounted mowers which is the high cost of labor needed for clearing the harvested wheat from the next tractor swath . The developed mowers were -tested and evaluated comparing with the other two types of mowers: a) tractor rear-mounted mower (Busatis B.M 1102 W-GERMANY manufactured B) self propelled mower (FERRARi 702 ITALIAN) under actual field conditions during 1987-1989. 79 Each type of mowers was tested under its recommended speed except the prototype which was te8te~ under two ditferent engine~speeds with three different gear variations I. II and III resultuing in 6 difterent forward speeds. The , variation in engine speeds were selected to suit the type of crop and field surface -con~itions. The results indicated that: 1- The average field capacities for front mounted mower (Prototype) were 0.089 and 0.529 ted/h./meter of cutter, bar width for harvesting of wheat and cutting stalks of cotton resp. The average field capacities for self-propelled mower were 0.407 and 0.342 fed./h./meter of cutter bar width for the harvesting of wheat and the cutting stalks of cotton resp. The average field capacities tor tractor rear mounted , mower were (0.736 and 0.65 ted/h./meter ot cutter-bar width) for harvesting ot wheat and cutting stalks ot cotton resp. 2- The average field etficiencies tor selt-propelled mower were very low since they were 55.2 % and 57. tor cutting stalks of cotton and harvesting wheat resp., while they become slightly high tor both ot the prototyp~ and the ,I. rear -mounted mowers, (67.2. and 73.82 _ )’ to~. the --~---_._- ---_ ... 80 prototype and (70.2% and 74%) for the rear mounted mower for cotton and wheat resp. , 3- The prototype showed better results in the cutting and harvestin~ efficiency by about (6% more than selfpropelled mower and by about 4% more than rear mounted mower since the cutting efficiency for the three mowers were 96%. 90 % and 92 % resp . • 4- The average heights ot cut for the prototype were 4 and 3.65 cm for cotton and wheat resp .. 12 and 10 cm for self -propelled mower. and 7.5 and 6.5 em for rear mounted mower resp. 5- The harvesting cost of wheat for the prototype was less than that for the self -propelled mower and rear mounted mower since their operating costs were 7.7. 14.9 and 17.7 L.E/fed resp. This cost variation was mainly due to the cost of labor needed for collection of the harvsted wheat during the operation ot the rear-mounted mower (2 labours. h Ifed.) 6- The cutting cost ot cotton stalks widely varied from 6.42.L. E./fed using the rear~ounted mower to 8.09 L.E.lted. and 17.77 L. E./fed when using the prototype (front mounted) and se1f-prope11ed mowers resp.These data indicate that rear ~ounted mower was economically I favorable machine to cut cotton stalks while seltpropelled mower was the most expensive machine to cut .. _---_ .. _-- 81 cotton stalks since its cost was almost equal to the cost of manual cutting was {22 L.E. Ifed. on the basis of 1989 prices} . Test of the improved rear mounted mower resulted in the following conculussions :- The improved rear -mounted mower had the best results in most of the evaluation parameters since. its field capacity reached 1.19 fed/~ .. its field efficiency was 80 % its cutting height was 4 em. its harvesting 10s8ee was 4 g/m2 ,and its harvesting cost was 6.83 L.E/fed. The only one disadvantage ot the improved rear mounted mower is the manual harvesting needed at the begining of operation to clear a swath for tractor around the field) inspite of that the rear mounted mower with conveyor ....•. is considered of’.’avorable machine for Egyption agriCUlture conditions. . This improvment wil decrease the harvesting cost spent in man power reqUired continuously • after normal rear mounted mowers also. it will raise the efficiency of the recent number of mowers used in egypt. |