Combined Foliar Zinc and Nitrogen Application in Broccoli (Brassica oleracea var. italica L.): Effects on Growth, Nutrient Bioaccumulation, and Bioactive Compounds

Abstract

To evaluate if the combined foliar application of nitrogen (N) and zinc (Zn) in broccoli improves the efficiency of the single Zn biofortification, five treatments were tested: (i) control; (ii) one Zn application at the beginning of flowering (0.5M1); (iii) combined 0.5M1 with N application (0.5M1N); (iv) two Zn applications, one at the beginning of the flowering and other after two weeks (0.25 + 0.25) and (v) combined 0.25 + 0.25 with N (0.25N + 0.25N). The Parthenon cultivar showed a good concentration of Ca, Fe, Mg, and Zn, with good bioavailability and glucosinolates, mainly in the florets, and high antioxidant activity and total phenols, mainly in the leaves, showing their potential not only as regards to human consumption, but also for the use of their by-products. All the studied treatments increased floret growth (19%), antioxidant capacity and total phenol content, not affecting Ca, Fe, and Mg concentrations. Glucosinolate content was mostly independent from the studied treatments, decreasing slightly in terms of glucoiberin and the Zn concentration in the florets increased in >50 mg Zn kg−1 in the split treatments and ~40 mg Zn kg−1 when the application was unique, with excellent bioavailability, measured as PA:Zn ratio. Therefore, 0.25 + 0.25 and 0.25N + 0.25N applications have been confirmed as the applications that improve more both growth and accumulation of Zn and biocompounds in broccoli.

Bioactive compounds, antioxidant activity, and mineral content of bróquil: A traditional crop of Brassica oleracea var. italica

“…Bróquil with an average of 83.7%I showed similar values to broccoli (84.9 %I), equivalent to 0.90 and 0.92 mg of TE g −1 dw, respectively. Zhang and Hamauzu (44) described in broccoli 61.7 %I and Rivera-Martín et al (45) found a content of 0.71 mg of TE g −1 dw, with both data lower or similar to bróquil results obtained using the same method. On the other side, as previously stated, broccoli has been described as a source of bioactive compounds, which possess antioxidant effects.…”

Zinc Biofortification Improves Yield, Nutraceutical Quality and Antioxidant Capacity in Lettuce

“…The plants require Zn concentrations of their leaves greater than 15-30 mg kg -1 dry matter for maximum yield, but excess levels of leaf Zn in the range of 100-700 mg kg -1 dry matter cause growth inhibition (White and Brown, 2010;Gupa et al, 2016). The foliar application of Zn has increased the productivity of wheat (Zou et al, 2019), mungbean (Haider et al, 2020), triticale (Dhaliwal et al, 2019), cowpea bean (López-Morales et al, 2020), chikpea (Pal et al, 2021), rice (Zulfiqar et al, 2021), broccoli (Rivera-Martin et al, 2021), maize (Augustine and Kalyanasundaram, 2021), among others.…”

Ecofriendly Application of Calabrese Broccoli Stalk Waste as a Biosorbent for the Removal of Pb(II) Ions from Aqueous Media

“…The weight percentages of the chemical composition of the raw biomass were as follows: 45.06% of C, 40.84% of O, 6.06% of K, 3.46% of N, 2.18% of Cl, 1.13% of Na, 0.38% of S, 0.33% of Ca, 0.25% of P, 0.2% of Mg and 0.11% of Cu (Figure 4a), according to the nature of broccoli stalks described in the introduction (e.g., sulfur-, nitrogen-and phosphorus-containing organic compounds (glucosinolates, proteins, phytic acid), minerals (Ca, K, Mg, P), etc.) [68]. In the same sense, the O/C ratio of 0.91 was closed to the unit, showing good hydrophilic properties of the biomass due to carboxylic, alcohols, ethers and aldehydes groups with a high degree of chemical functionality.…”