Impact of rhizobium inoculation and boron application on morphological alterations and biochemical triggers in pea (Pisum sativum L.)

Abstract

Rhizobium is a bacterial culture that enhances the speed of biological nitrogen fixation in association with root nodules in pulse crops while boron act as a catalyst for cell division hence the size of nodules and sugar translocation in the plant. An experiment was conducted by considering rhizobium as a seed inoculant and boron as a soil applicant in two peas (Pisum sativum L.) varieties Arkel and Azad Pea-3 to know the morphological alterations in plant height (cm), fresh and dry weight g plant^-1), number of leaves (plant^-1), and days required for the first flowering and picking. However, the biochemical triggers were also observed for soil plant analysis development reading (SPAD), total chlorophyll (mg g^-1) and derivative (chlorophyll a and b), protein (mg g^-1), and proline content (µg g^-1) in both varieties of pea (Arkel and Azad Pea-3). The performance of V₂ was superior to V₁ for most of the morphological and biochemical parameters. The combination of rhizobium + 2.0 kg boron ha^-1 (T₅) was observed as the best treatment compared to the rest of the treatments in V_1, while the rhizobium + 1.5 kg boron ha^-1 (T₄) in V₂. Among the treatment combinations, T₅ and T₄ were recorded as minimum days for the first flowering (39.3 and 43.0), while the maximum days for the first picking (75 and 84) in V₁ and V₂. The highest SPAD reading, total chlorophyll, and protein were also noticed in T₅ and T_4, while chlorophyll a was recorded at maximum value in T₄ for both varieties. However, the value of chlorophyll b was recorded as maximum in T₄ and T₃ at 50 DAS, while T₅ and T₄ were at 75 DAS. A trigger of proline content was also noticed in T₅ and T₄ of both varieties compared to the control set. The positive alteration in morphology and biochemical changes in pea plants due to the application of rhizobium in combination with boron interlink well for the betterment of yield via increasing the rate of photosynthesis.