Nitrogen Management for Commercial Citrus Production

Proper management of nitrogen is an essential element to successful citrus production.

While growers seek every unique advantage they can to produce superior crops over their competition, often there are unavoidable common ties – even among the most sophisticated proprietary plant nutrition programs. Case in point, nitrogen is a key ingredient in most every plant food recipe. As well it should be given the element’s impact across the vast growth spectrum. Micro-managing this macronutrient is necessary, as there is a fine line between the benefits nitrogen can bring to a crop and the possible damage it can inflict due to an application mishap.

Nitrogen has more influence on tree growth, appearance, fruit production, and quality than any other nutrient element, says Mongi Zekri, UF/IFAS multicounty citrus agent based in LaBelle, FL. “Too little nitrogen will make trees stunted, flush irregularly, bloom sparsely, and yield a low crop of poor-quality fruit,” he says. “Excessive or late applications of nitrogen can induce excess vigor and promote a vegetative rather than a flowering tree, reduce fruit production, fruit quality (including low soluble solids), and delay fruit maturity and color.”

In order to play to nitrogen’s strengths, taking three basic steps can help manage input to optimize yields and quality, according to Zekri. The first step would be to perform an evaluation of leaf analysis data. The information found there should reveal what is lacking. The second would involve the selection of fertilizer formulations to match existing grove conditions. Last but not least, are the adjustments of rates based on the level of nitrogen needed for expected fruit yield?

Even though you might have found the right nutrient blend for your trees, it doesn’t guarantee the delivery of the product. Nutrient uptake is as important to the plant health equation as the formula itself. Zekri says there are several ways to increase the effectiveness of nitrogen uptake in citrus. Two of the most common approaches today – especially given the urgency of Florida’s citrus growers to try to get prolonged productivity out of their groves amid extreme HLB pressure – are foliar nutrition and fertigation. “Foliar feeding and fertigation can improve nutrient use efficiency, increase yield, and enhance fruit quality,” Zekri says.

Nitrogen uptake in citrus also is driven through proper balance with the other plant nutrients, Zekri says. A split fertilizer application is helpful when combined with sound irrigation equipment, he adds.

Timing is a final factor to consider. Zekri recommends having most of the nitrogen in place during the flowering and fruit-setting periods. “If it is soil-applied, then apply soil nitrogen fertilizers frequently in small doses and place them in the wetted area where most active roots are located.”

While many citrus fertilizers are available, studies show that KeyPlex micronutrient products can boost growth, increase yields, foster health and vigor, trigger defense mechanisms, and reduce environmental stress in citrus crops. For more about KeyPlex citrus solutions, visit