The research aimed to estimate the optimal quantities of resources used in producing the watermelon crop in Samarra district for the 2023 production season, through which it is possible to achieve economic efficiency in the farms of the research sample. The data was obtained by designing a questionnaire in the style of random sampling of the farms in the field, as the sample size is based on its proportion in the population for 30 farms. The research relied on the method of descriptive and quantitative analysis in accordance with the logic of economic theory, using the DEAP program to analyze data and estimate the size of the surplus and deficit of the resources used in producing the watermelon crop. The results of the research showed that there is a waste in the amount of resources used. The fertilizer supplier ranked first in the quantities used, while the pesticide supplier ranked last in the amount of waste. The reason for this is the increase in the use of the resource in a way that is outside the quantities recommended by the competent authorities necessary for cultivating one dunam, as well as the absence of agricultural guidance and counseling that must be provided, which In turn, it had a negative impact on the use of this resource, and the research recommended the need to activate the role of the extension system in educating farmers about the optimal use of the resource, which enables them to achieve economic efficiency in the farms.