Soil and foliar zinc biofortification of broccolini: effects on plant growth and mineral accumulation

Abstract

Millions of people have Zn-deficient diets, so Zn-biofortified crops could prevent such deficiency. The aim of this study was to evaluate the use of agronomic Zn biofortification of broccolini – a new hybrid crop variety derived from a cross between kalian cabbage and broccoli. Plants were grown in pots using a Zn deficient soil. Four fertiliser treatments were tested: (1) control; (2) soil application of 5 mg ZnSO4•7H2O kg–1 soil; (3) foliar application at the early flowering stage of 0.5% (w/v) ZnSO4•7H2O; (4) combined soil and foliar treatments. Florets were harvested in four sequential harvests. There was a decrease in both growth and leaf composition of Zn, Ca, Fe and Mg. Soil Zn application increased floret production. There were increases in the Zn concentration stem+leaves and florets of 12- and 2.5-fold in foliar and soil+foliar treatments respectively. PA:Zn molar ratios decreased under both foliar and soil+foliar treatments. Boiling reduced Zn concentration by 40%, along with a decrease of other mineral nutrients. A soil+foliar treatment can increase both plant growth and Zn concentration in broccolini, and boiled 100 g portion of biofortified florets fertilised at rates in this study would deliver ~49 mg Zn, a 46% increase than in the non-biofortified broccolini.

Agronomic Biofortification with Se, Zn, and Fe: An Effective Strategy to Enhance Crop Nutritional Quality and Stress Defense—A Review

“…Skrypnik et al (2019) noted that the application of Se to the nutrient solution had a significant effect on the essential oil content in basil leaves compared to foliar application. Some authors suggested that the combined application of Zn, Fe, and Se soil and foliar fertilizers (Gomez-Coronado et al 2016;Rivera-Martin et al 2020) and fertilization with amendments like, i.e., biochar or salicylic acid (Ramzani et al 2016;Smoleń et al 2019) influenced a better efficiency for microelements accumulation in crops compared to when used separately. For example, it was found that Zn fertilization improved Fe concentration in grains (Niyigaba et al 2019).…”