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More and tastier with Ultrasol®

This SQM Ultrasol® nutrition programme resulted in an additional net income for the farmer of about 6.000 US$/ha.

“The orange from the Vidarbha region is famous in India for its excellent taste. Over 100.000 hectares of citrus are planted in this belt in the North-East of MaharashtraState. Orchards in this area are traditionally flood irrigated and most of them are nutritionally neglected. In recent years, however, more and more farmers are adapting drip irrigation and are eagerly looking for new practices to improve their crop yield and quality” reports Fere Dattatray, Agronomist at SQM Agro India.

SQM’s first visit to the area dates back to July 2005 after which was decided to set up a fertigation programme with well-balanced plant nutrition. During spring 2006, over 165 farmers in the Vidarbha region were again visited at their orchards to note down their problems: low fruit set, low fruit size, low fruit fill and poor skin quality.

A popular traditional fertiliser programme in this area includes NPK 18-18-10, SSP, organic manure rich in nitrogen and a Zn based micro-nutrient mix; all applied as soil application without any soil or leaf analysis. After careful consideration of all the above points, SQM Agro India recommended a well-balanced fertigation programme based on Ultrasol® K, Ultrasol® 19-19-19, Ultrasol® MKP, Ultrasol® Calcium and Ultrasol® Magsul. The first results of the February 2006 flowering season were collected end of December 2006. On average, fruit retention improved with 38% and the fruit weight increased by 25%.

Peel finish was considerably better, contributing to a higher market price for the farmer. Probably the most important factor that resulted in a doubling of the market price to the farmer was the delayed maturity that can be explained by the prolonged assimilation period of the orange due to the better nutritional status of the trees.

These oranges received the traditional farmer fertiliser programme and clearly suffer from poor skin quality
These oranges received the traditional farmer fertiliser programme and clearly suffer from poor skin quality.

As a result of <b>SQM</b>`s well-balanced fertigation programme, fruit retention improved on average with 38% and the fruit weight increased on average by 25%
As a result of SQM`s well-balanced fertigation programme, fruit retention improved on
average with 38% and the fruit weight increased on average by 25%.




300 - 500

Number of fruits/tree

600 - 690

6,6 - 6,78cm

Fruit size (diameter)

6,98 - 7,18cm

100 - 125g

Fruit weight

140 - 156g

3,9 - 4,1mm & rough skin

Peel thickness and peel finish

3,70 - 3,77mm & good skin finish

hollow fruits

Fruit fill


Boosting profitable citrus yield with Ultrasol® K Plus potassium nitrate.

Achieve higher yields and increase quality of your citrus crop with foliar applied Ultrasol® K Plus potassium nitrate

• Increased marketable yield:

• Increased fruit weight.
• Larger fruit size.
• Improved peel color.
• Reduced peel defects (splitting, creasing).
• More: vitamin C content, juice content.
• Longer shelf life

• Increased resistance to peel damage, frost, pests and diseases (general K effect).

Potassium nitrate (KNO3) characteristics

• Chloride-free K source – no salt stress.
• Nitrate Nitrogen (NO3-) for direct absorption.
• Synergism between K+ and NO3uptake..
• Low salt index of 72 – reduced risk of leaf burning.
• Highly soluble (2.65 lbs/gallon at 68°F or 316 g/l at 20°C).
• Tank mix compatibility with the majority of water-soluble fertilizers and pesticides.

Situations that make foliar plant nutrition with Ultrasol® K Plus very beneficial

• When the uptake of nutrients via the root system is limited:

• Root damage: diseases, mechanical damage.
• Unfavourable soil conditions.
• Too wet (water logging, low oxygen content), too cold, too dry.
• Nutrient deficiency or excess imbalance in the soil.
• Fixation.
• Salinization.
• When peak demand of tree exceeds nutrient supply capacity via the roots.

• In situations when localized within-plant demand may exceed capacity of within-plant nutrient redistribution.

• As in the vicinity of large fruit and nut clusters with high localized demand of many nutrients in the fruit.

• Limited nutrient mobility when flowering precedes leaf expansion and thereby limits xylem nutrient transport.

Foliar KNO3 research in citrus

Research conducted by the University of Florida has shown that three foliar applications of KNO3 at a rate of 25 lb/acre/spray applied pre-bloom (mid-Feb.), post-bloom (April), and summer (July/August), totaling 75 lb KNO3/acre, increased yield and size of fresh market 'Valencia' orange when compared to an untreated control (Table 1). Both treatments received standard recommended soil fertilizer applications applied 3-4 times throughout the season.

Table1. The effect of 3 foliar applications with 25 lbs KNO3/acre/spray on fresh market "Valencia" orange yield and grower´s income.
*1 box = 90lbs**gross return on fresh fruit market value
Source: Boman, B.J. 2001, Foliar nutrient sprays influence yield and size of "Valencia" orange. Proc. Fla. State Hort. 114;83-88



LSD 5%


LSD 5%

lbs tss/acre

LSD 5%

grower gross returns/oc**

LSD 5%

Potassium Nitrate


















%Increased with Potassium Nitrate





Ultrasol® K Plus

Total Nitrogen Content (N)

13.7% (min)

Total nitrate nitrogen content (N-NO3)

13.7% (min)

Total potassium content (K2O)

46.3% (min)

Total chloride content (Cl)

< 0.2%

Solubility (g/l at 206deg;C)



< 0.005%

EC (g/l at 25°C, in mS/cm)


pH (1% solution)

8 - 9

Form and Color

Crystalline, odorless white powder