Maize plants need zinc to grow well, but sometimes the soil doesn't have enough. Scientists in Pakistan tested different ways to give maize plants zinc, like putting it in the soil or spraying it on the leaves. They found that spraying zinc on the leaves when the plant had 9 leaves gave the best results. This method increased the grain yield by 38% compared to not giving any zinc. So, spraying zinc on maize plants can help them grow better and produce more grain.