Seeds enriched with molybdenum improve cowpea yield in sub‐humid tropical regions of Brazil

Abstract

The possible benefits of molybdenum (Mo)-enriched seeds for grain legumes have yet to be addressed in sub-humid tropical areas, where cowpea (Vigna unguiculata L.) is an important crop. In 2016, seeds with 0.014 (low), 0.674, or 1.987 (high) μg seed −1 of Mo were harvested from plants sprayed with 0, 250, or 850 g ha -1 of Mo, respectively. These seeds were combined with either Bradyrhizobium inoculation (with or without) in 2017 or nitrogen (0 or 60 kg ha −1 ) in 2018 and evaluated under small farmer management in Maranhão State, Brazil. Maximum nodules plant −1 in these trials was 5.2. In 2017, inoculation acted synergistically with Mo-enriched seeds by increasing nodule weight. Averaged across inoculation levels, plants originated from high-Mo seeds had 36% higher leaf N concentration than those raised from low-Mo seeds. Inoculation did not affect yield, but plants grown from high-Mo seeds yielded 42% more than those raised from low-Mo seeds. In 2018, seed Mo content did not affect nodule and yield where urea was applied. However, without urea, plants raised from high-Mo seeds had 3.5-fold greater values for nodule number and weight and yielded 70% more than those grown from low-Mo seeds. We conclude that using Moenriched seeds associated with Bradyrhizobium inoculation would improve cowpea N nutrition and yield in a sustainable way.How to cite this article: Barbosa EPA, Sodré DN, Braun H, Vieira RF. Seeds enriched with molybdenum improve cowpea yield in sub-humid tropical regions of Brazil.

Fixação biológica de nitrogênio em feijão-caupi em resposta á inoculação com bradyrhizobium e diferentes doses de molibdênio

“…Para a variável massa fresca da raiz sem os nódulos (MFRSN), os maiores pesos foram dos tratamentos com 50 g.ha -1 de molibdênio na ausência e na presença da inoculação, que proporcionaram pesos médios de 3,5 e 3,25g, respectivamente. Mostrando que nesta dosagem de molibdênio os nódulos apresentaram um maior peso e tamanho, mesmo na ausência do inoculante rizobiano assim como a variável comprimento radicular também foi influenciada pelo mesmo tratamento (Barbosa et al, 2021).…”

Split applications of molybdenum fertilizer on common bean increase molybdenum in seed

“…This micronutrient is readily mobile in the xylem and phloem (Bittner, 2014;Broadley et al, 2012) of plants, where it is required in small amounts by enzymes that cat-store an amount of Mo that exceeds plant needs (Meagher et al, 1952). These seeds may accumulate Mo when mother plants are either grown in Mo-rich soils (Brodrick et al, 1992;Harris et al, 1965) or they are fertilized with Mo (Barbosa et al, 2021;Jacob-Neto & Rossetto, 1998;Vieira et al, 2011). When Mo fertilizer is used to enrich seeds, foliar applications are more efficient than soil application (Jacob-Neto & Rossetto, 1998).…”

“…The effectiveness of sowing Mo‐enriched seeds in increasing seed yield has been demonstrated for common bean ( Phaseolus vulgaris L.) (Brodrick et al., 1992; Pacheco et al., 2012; Vieira et al., 2011), cowpea [ Vigna unguiculata (L.) Walp.] (Barbosa et al., 2021), soybean [ Glycine max (L.) Merr.] (Campo et al., 2009; Harris et al., 1965), and other legume crops.…”

Layered Double Hydroxides as Slow-Release Fertilizer Compounds for the Micronutrient Molybdenum

“…Molybdenum is an essential micronutrient for plants and performs a vital role as a cofactor in several plant enzymes, such as nitrate reductase and aldehyde oxidase . Although Mo is required by plants in very small amounts, Mo deficiencies are common in high rainfall environments, − particularly with Brassica crops ( e.g. , cauliflower and rapeseed), which are known for their relatively high Mo demand .…”