The potato (Solanum tuberosum L.) field experiment commenced in the spring growing season of 2023 at the Musayyib project area, Babil Governorate, Iraq. The study aimed to determine the effects of biofertilization with four levels (without adding + full recommended fertilizer, addition of 10 g mixture of four types of bacterial fertilizer + half of the recommended fertilizer, addition of 10 g fungal biofertilizer (mycorrhiza) + half of the recommended fertilizer, and addition of 10 g mixture of bacterial and fungal biofertilizers + half of the recommended fertilizer) symbolized as B0, B1, B2, and B3, respectively. The nanofertilizer used had two nano-fertilization concentration, which had a positive effect on the average tuber (0 + full fertilizer recommendation and 2 g L^-1 + half the fertilizer recommendation), denoted as N0 and N1, respectively, on the growth and tuber yield of three potato cultivars (Rashida, Sifra, and Arizona). The results showed cultivar Arizona was superior to the rest of the cultivars in emergence speed, plant height, chlorophyll content, tuber weight, and plant yield, with average values of 36.73 days, 60.29 cm, 48.30 mg 100 g^-1, 123.8 g, and 0.955 kg plant^-1, respectively. The B3 biofertilization treatment (bacterial and fungal fertilizer) and nanofertilizer (2 g L^-1) showed significant superiority in emergence seed, plant height, chlorophyll content, tuber weight, and plant yield.

Keywords: Potato (Solanum tuberosum L.), biofertilization, bacterial and fungal fertilizer, nanofertilizer, growth and tuber yield traits, chlorophyll content

Key findings: Potato (Solanum tuberosum L.) cultivar Arizona emerged superior over the rest of the cultivars in speed of emergence, chlorophyll content, tuber weight, and plant tuber yield. Biofertilization treatment B3 (a mixture of bacterial and fungal fertilizers) and nanofertilizer (2 g L^-1) showed significant superiority in most traits.