Crop Guide: Nutrients for Pepper

Suit Pepper Fertilizer Products and Nutrition Plan to Growth Needs

Overall requirements

The table shows typical ranges of nutrient uptake by pepper crop.

Learn about the roles of various plant nutrients and discover the fertilizers that supply them 

Management of Macronutrients

Nitrogen (N) supports the vegetative growth of pepper plants. It is crucial for the plant to be well-developed vegetatively by the time it reaches the flowering stage; otherwise, its yield potential will be limited. Pepper plants respond positively to adequate nitrogen by increasing the number of flowers and fruits. A high NO₃⁻/NH₄⁺ ratio (4:1) is preferable, as it ensures sufficient nitrogen supply without causing cation deficiencies (Ca²⁺, K⁺), which may result from competition with NH₄⁺.

Phosphorus (P) is vital for proper root development during early growth stages and for the formation of reproductive organs (flowers, fruits, seeds). Phosphorus deficiency leads to short branches, numerous undeveloped buds, and reduced fruit production. When growing peppers in soilless media, it is recommended to use fertilizers containing phosphorus in the form of polyphosphates rather than conventional sources such as MAP or MKP. Polyphosphates improve phosphorus availability and help prevent the formation of insoluble precipitates in the system.

Potassium (K) enhances carbohydrate accumulation and increases resistance to low temperatures and diseases. Pepper plants begin accumulating potassium about one month after planting, with uptake steadily increasing until the first harvest. During the early growth stages—up to flower formation—balanced levels of potassium and nitrogen are essential for proper development.

From the onset of flowering through fruit maturation, potassium demand rises significantly, aligning with the plant's fruit development needs. To support this, high nitrogen application is required early in the growing season, followed by supplemental applications after fruit initiation.

Potassium deficiency slows plant growth and causes visible symptoms such as brown spots on leaf and fruit edges, leaf curling, and drying. Severe deficiency disrupts sugar transport within the plant, leading to starch accumulation in the lower leaves. 

The figure below depicts the dynamics of macronutrient uptake by pepper crop (kg/ha/day),

Pepper cv Maor,  seeding: July 14^th, Soil type: Sand, Planting density: 100,000 plants/ha, Expected yield: 75 ton/ha

General guidelines for pepper nutrition by growth stages

	Establishment  At the early stages of establishment, till 30 days after transplanting, the developing root requires high levels of phosphorus (P). N-P2O5-K2O ratio of 1:2:1 is recommended at this stage. This then changes to ratio of 1:1:1.
	Vegetative growth  The 1:1:1 ratio is recommended at this stage too, though quantities should be increased to meet the demands of the growing plant.
	From initial flowering till fruit-set  When reproductive processes take place, the plant requires larger quantities of potassium while phosphorus requirements drop. The recommended N-P2O5-K2O ratio now is 2-1-3.
	Fruit development and maturation The recommended N-P2O5-K2O ratio at this stage is 2-1-3.

Calcium (Ca) nutrition of Pepper Crop

Calcium is essential for the building of cell walls. Poor calcium supply interferes with this important function, resulting in distorted growth and deformation of root tips, young leaves, and shoot tips. In addition, weaker cells are more susceptible to biotic attacks.  

Calcium deficiency is not necessarily caused by insufficient calcium fertilization or low soil calcium levels; rather, factors that limit its availability to the plant play a crucial role. These include high transpiration rates, water shortage, high salinity, and an excess of competing cations in the soil solution or growing medium (such as ammonium, potassium, and magnesium).

Blossom End Rot (BER)

Blossom End Rot (BER) is a common physiological disorder in peppers that can lead to significant yield loss. As the name suggests, the disorder appears as a dark, sunken area at the lower (blossom) end of the fruit. The disorder typically affects fruits during their early development stages (10–15 days after fruit set). It is caused by an imbalance between the fruit's rapid growth and the calcium supply, resulting in the collapse of certain fruit tissues due to localized calcium deficiency.

Several factors can contribute to BER, all of which are linked to limited calcium uptake and transport to the developing fruit. These include salinity, high temperatures, vigorous vegetative growth, and water shortages.

BER can be effectively managed through careful regulation of water and calcium supply, as well as by reducing competition from other cations. To support calcium uptake:

• Favor nitrate nitrogen over ammonium nitrogen (maintain a NO₃⁻/NH₄⁺ ratio of approximately 4:1 or higher).

• Maintain a K/Ca ratio of about 1:1 in irrigation water during hot seasons.

Pepper Spots appear as grey or black spots on the pepper fruits. The spots develop under the fruit’s skin, about the time the fruit attains a diameter of 8 centimeters or more. As the fruits ripen, the spots slightly enlarge and turn green or yellow. 

Pepper Leaf analysis standards

1. Macro and secondary plant nutrients contents in pepper leaves (% in dry matter)

2. Micronutrient contents in pepper leaves (ppm in dry matter)