Don’t worry about corn tip sterility—choosing the right fertilizer is key!

China’s corn acreage stands at approximately 300 million mu, second only to wheat, making it a major grain and feed crop. In production, phenomena such as barren tips and reduced kernel set occur annually, leading to substantial yield losses; insufficient supplies of boron and zinc are the primary causes of these issues.

The roles of boron and zinc

During maize growth, the crop requires not only macronutrients such as nitrogen, phosphorus, and potassium, but also micronutrients like boron and zinc. Boron primarily regulates carbohydrate metabolism and plays a crucial role in protein synthesis, the formation of seeds and cell walls, pollen grain germination, and pollen tube elongation. When boron is deficient, pollination and fertilization are impaired, leading to sparse kernels and barren tips in maize. Zinc, on the other hand, mainly functions by regulating the synthesis of indole‑3‑acetic acid and the biosynthesis of carbohydrates.

Boron and zinc deficiency symptoms

Boron deficiency in maize leads to difficulty in the expansion of young leaves during the seedling stage, with damage to leaf tissue and the appearance of broad white stripes between the veins. The roots become thickened and brittle, and the root tip cells undergo lignification. During the flowering and pollination period, boron deficiency results in poor emergence of the tassel, reduced branching, and degeneration of male flowers; the female ear fails to develop normally, sometimes even producing a barren stalk. In the later stages, the kernel rows on the ear become distorted, kernel set is low, and the ear tip often turns black, leading to bare tips or reduced grain production.

Zinc deficiency in maize impairs chlorophyll synthesis, leading to stunted seedling growth, smaller leaves, and dwarfed plants, which can result in white‑striped seedlings. During the flowering and pollination stages, zinc also plays a critical role in numerous enzymatic reactions; moreover, it significantly affects pollen viability. Consequently, zinc deficiency can compromise fertilization and pollination, causing reduced kernel set and barren tips.

Cause of occurrence

Zinc and boron deficiencies in maize are most prevalent in summer‑maize growing regions, which are concentrated in the Huanghuai and North China areas, including Henan, Shandong, Anhui, Hebei, Shanxi, and Shaanxi. These regions naturally have low levels of zinc and boron in their soils, and combined with high summer temperatures and heavy rainfall, this leads to the leaching of micronutrients such as boron and zinc. Moreover, farmers often fail to apply supplemental fertilizers, resulting in soil concentrations of these trace elements that fall far short of meeting the nutritional needs of maize during its growth and development.

Control methods

Base application: When planting corn, it is advisable to use a fertilizer enriched with zinc and boron, or to mix 1–2 kilograms of zinc sulfate into the compound fertilizer and apply it together with the seed. This approach generally suffices to meet the crop’s nutrient requirements throughout its entire growth period.

Foliar fertilization: During the jointing and flowering‑pollination stages of corn, apply a foliar fertilizer containing boron and zinc (such as Nongda Ye Geli) or use a 0.5% zinc sulfate solution directly. Typically, spray every 10 days for 2–3 applications; this effectively prevents poor pollination, reducing kernel set and minimizing barren tips.