Studies On Machinery For Low-volume Appucation Of Agricultural Chemicals:

Abdulelah Omar Ahmed Saif

This study was carried out to evaluate the technical andeconomical characteristics of four types of chemical applicators(Knapsack hand operator sprayer,knapsack air-carriersprayer, stationary field sprayer, and mounted-boom fieldsprayer) .All sprayers under study were tested and evaluated bymaking comparison between them to study the following points:1- Field efficiency.2- Actual productivity.3- Covering efficiencies.4- Operation costs.5- Economical advantages criterion.The important results obtained from this study can besummarized as follows1- Field efficiency :It was found that the stationary field sprayer {S3} gavethe highest field efficiency {60%}, comparing with the threesystems of sprayers {knapsack hand sprayer, knapsack aircarrier,and mounted-boom field sprayer} {42, 41 and 16%} .The differences between them are due to the time losses ofspraying.-89-2- Actual productivity :from the results, the mounted-boom field sprayer gave(5.92 ha/h) actual productivity comparing with the otherssystems (knapsack hand sprayer, knapsack air-carrier, -andstationary field sprayer) (0.49, 0.68 and 1.31 ha/h) , this isdue to the differences between them in forward speeds, andwidth of sprayers.3- Covering efficiencyThe systems under study differed in covering efficiencydue to the differences between their natures of the method ofspray application. It was found that the knapsack air-carrier .sprayer gave the best covering efficiency (78%) comparingwith the others systems (knapsack hand sprayer, stationaryfield sprayer, and mounted-boom field sprayer) which gave18%, 53% and 21% resp.4- Operation costs :The highest cost/h per one operating hour (17.L.•E/h) wasrecorded by mounted-boom field sprayer, mean while the samesystem gave the lowest operation cost/ha (2.93 L.E/ha), comparingwith the knapsack hand-sprayer, knapsack air-carrier,and stationary field sprayer, which gave (2.065, 6.285 and8.33 L.E/h and 4.21, 9.25 and 6.30 L.E/ha resp. These resultsare due to the increasing in actual productivity for systemmounted-boom field-sprayer decreasing operation cost per ha.-90-5- Spray modeling program :from this study computer program can be made for sprayingmachine to select the optimum spraying machine under differentoperation condition via input required data in theprogram.6- Economical advantage criterion :The knapsack air-carrier gave the highest economicaladvantage criterion (1357.72 L.E/ha) comparing with systemsof knapsack hand sprayer, stationary field sprayer, andmounted-boom field sprayer, which gave (302.85, 922.18 and357.98 L.E/ha) resp. The knapsack air-carrier recorded thehighest economical advantage criterion L.E/ha, although itgave the highest seasonal cost (46.25 L.E/ha), but with thebest covering efficiency (78%), which caused an increase inthe final yield of cotton.New contribution in this researchA computer program was devised to compare between differentspraying machinery in different situations. The’programhas 3 main subroutines: (1) productivity factors, (2) operatiGncost factors, and (3) an economical-advantage criterion whichcombines the effects of cost and yield variations due tospraying, to guide selection of optimum spraying machineryfor different situations.RECOMMENDAT:IONSfrom this research the following can be recommended- The use of the knapsack air-carrier sprayer in cotton pestcontrol. This is due tQ high covering efficiency resu+tingfrom its application.- Development of this sprayer for greater swath width, andfor local manufacturing.- Availing this type of sprayer for use in mechanizationcenters.- Carrying on with more research on nozzle boom for mountedsprayers, and investigating the possibility of using airjets to aid in spray coverage. Care also should be given toperform other field operations in a way to allow properpest control mechanization (starting from soil preparationand ending with harvesting) .