Three planting spaces (7, 10, and 13 cm.) between seeds and the effect of humic acid with the recommended dose (2 kg/feddan) and different rates of NPK fertilizer (humic 100%, NPK 100%, Humic + 25% NPK, Humic + 50% NPK, Humic + 75% NPK, Humic + 100% NPK, and control) were evaluated throughout the 2019 and 2020 seasons at Suez Governorate to determine their combined effect on the population density of certain insect pests, aphids (mainly Aphis gossypii, Myzus persicae, and Aphis craccivora), whitefly, Bemisia tabaci , jassids, Empasca lybica, and rust disease severity, Uromyces appendiculatus on common bean plants, Phaseolus vulgaris (Nepraska cultivar), and pod yield. Common bean plants cultivated in the closest and intermediate planting spaces (7 and 10 cm between hills) harbored the significantly highest infestation of all four pests. The significantly lowest infestation of the three studied insects and rust disease was obtained from common bean plants treated with humic acid plus 50% NPK. The four studied pests and produced yield were significantly affected by both two studied factors together, as the treatment of humic acid + 50% NPK at the three tested spacings (7, 10, and 13 cm) showed the lowest infestation and gave the highest weight of pods. Common bean plants grown in control treatments that did not receive any fertilizers were infested with the least significant numbers of the three studied insects due to the weakness of the plant and the lack of sufficient vegetation while infected by the heaviest rust disease severity.