Deficiency

To qualitatively evaluate the level of nitrogen (N) in the field, it is recommended to do the "test" of diphenylamine in petioles. This consists of applying a drop of the reagent on a cut petiole in half. If a blue color develops rapidly, the content should be more than 2.8% nitrogen (N), even more the values ​​of N - NO3 would be over 500 ppm, then the plant would be well supplied with nitrogen. If this color develops slowly, or the area of ​​application it is discolored, the plant is out of stock. With more than 2.5% nitrogen (N) it is guaranteed a good production. This reagent is prepared by adding 0.2 grams of diphenylamine in 100 cc, in concentrated sulfuric acid (P.A) in which it is packaged in a pyrex bottle; of this and with dropario can be used. This reagent must be handled with care as it is highly caustic. Nitrogen (N) is the nutrient in greatest demand by the plant. Its lack influences negatively, the leaves are smaller and as the deficiency increases the leaves develop a luster metallic in some varieties; excess is manifested by abnormally developing leaves large and performance decreases. After flowering, the nitrogen (N) level should be above 2.5%; having a lack on the leaves, there is a discoloration of the foliage, which turns yellowish; while the older leaves take on a reddish coloration. As this deficiency worsens, produces browning and necrosis of small areas. The strawberry has three periods of greatest nitrogen demand (N); in spring, at the end of summer and at the beginning of autumn, when are forming the fruit buds. Immature leaves turn greener with low content. nitrogen (N) not so those that are fully expanded. Roots store nitrogen (N) for the winter and its content decreases in spring, when flowering occurs and fruits are formed. In this species, the roots have their maximum development after the harvest season -at the end of summer- and they keep growing in winter. Its development compromises the viability of the plant. An excess of vigor at the beginning of spring will stimulate the plant to use its reserves, to the detriment of fruiting. The roots have less development such as lack of calcium (Ca) and boron (B). The flowers and fruits of deficient plants are smaller than normal and the fruit develops albinism. As the deficiency progresses the fruits become smaller and yet and although seems contradictory a slight deficiency improves the quality of the fruit and therefore the price in the market.

Deficiency Correction

Because it is a very superficial rooted plant, the absorption of nitrates is rapid (90% of the roots are in the first 20 cm of soil). If the plants did not have a good development in the previous season, fertilizing in spring is suggested. If not, it is recommended do it in the fall. Fertilizing early in spring and then in late summer is suggested. Can use any nitrogen carrier (N), alternatively incorporate into the drip system approximately 40 units of N/ha. Lastly, the yellowing may probably be due to a lack of items such as a lack of sulfur (S), molybdenum (Mo) or another element.

Deficiency

With phosphorus (P) deficiency, the foliage turns an intense green (bluish-green) color, which associated with reddening of the edge of the blade. The leaves are smaller in size; and custom As the deficiency progresses, the blade takes on a metallic luster in some varieties. The underside of the The leaf takes on a reddish purple color and the vegetative development is delayed, even when the development root appears normal. The flowers and fruits of deficient plants are smaller, where the fruit can develop albinism, similar to nitrogen (N) deficiency. The roots have less development such as with a lack of nitrogen. When the phosphorus or phosphate in the petioles of the leaves is less than 700 ppm on a dry weight basis or the Phosphorus (P) is less than 0.2% dry weight basis.

Deficiency Correction

It is corrected with fertilizers carrying phosphorus (P), by applying 50 kg/ha of P, this when deficiency appears and/or incorporate phosphoric acid into the irrigation system.

Deficiency

The symptom of potassium (K) deficiency changes depending on the variety, climate and type of soil. Generally confused with magnesium (Mg) deficiency, or with burns caused by damage due to excess chlorides (Cl) and/or damage from pests or diseases. Browning occurs on the upper margin of the leaf, while the mature leaves dry up, compromising the interveinal tissue; some take on a reddish color. New leaves do not show these symptoms. The fruit does not develop full color, tastes bland; the roots are dark in color, but are recover with the application of this element. Regarding the sodium ion (Na), which is antagonistic to the potassium ion (K), the plant presents selectivity to the absorption of sodium (Na), being convenient let the plant absorb it. A leaf with less than 1% potassium indicates deficiency.

Deficiency Correction

It is corrected by applying potassium nitrate (KNO3) or potassium sulfate (K2SO4) applied to the soil. at a rate of 90 kg/ha at the time of planting or on the sides of the row. Alternatively incorporate this fertilizer into the drip system; as potassium nitrate (KNO3).

Deficiency

This deficiency is not a common occurrence. Fruit growth is reduced and the root growth. The roots are damaged and the leaves become brittle and have sharp edges. chlorotic or yellowish. Exudations occur on the underside of the leaves. These symptoms also can be recorded on mature leaves. In addition, on the leaves there is an apical burn "tip burn" which occurs in the period of rapid leaf growth, this does not occur in all varieties. The fruit becomes firmer and has an acid taste.

Deficiency Correction

It is recommended, before planting, to apply agricultural plaster (CaSO4 * 2 H2O) in doses of 500 - 1000 kg/ha as cover, especially on acid soils. It is also corrected by spraying foliarly with calcium chloride (CaCl2) at 0.4%, beginning when flowering occurs (3 applications every 2 to 3 days).

Deficiency

The leaves are deformed and the margins take on a yellowish green color, to advance to the area interventional. Then necrosis occurs, keeping the base of the leaf pale green. The fruit is smaller in size, tends to albinism, however its appearance or quality does not change.

Deficiency Correction

Magnesium sulfate (MgSO4) can be applied before planting or in top dressing (50 - 100 kg/ha). Alternatively, magnesium sulfate and/or magnesium nitrate can be used. Mg(NO3)2 in the technical irrigation system.

Deficiency

This deficiency is easy to identify, since a pale green halo is produced at the edge of the blade of new leaves; which is maintained in the mature leaves. As the deficiency advances, the leaves become narrower and more elongated (when it is severe). The leaves more new ones become chlorotic to yellowish, but not the vein. As the leaves grow old the tissue turns reddish. The root system is fibrous, while the quantity and size of the fruit decrease, when the leaves have less than 10 ppm of zinc (Zn).

Deficiency Correction

It is corrected with foliar fertilizers that carry this element. In this regard, spraying can damage the plant, so it is worth trying it on some beforehand (both the product as the dose), given because it can cause damage to the flowers and/or the fruit. Before planting, it It is recommended to apply zinc sulfate (ZnSO4) in cover (1 to 3 gr/linear meter). It is also possible to apply sulfuric acid (H2SO4) in the irrigation system.

Deficiencia

La carencia de manganeso (Mn) se manifiesta por un amarillamiento de las hojas nuevas; síntoma parecido a la deficiencia de hierro (Fe) o azufre (S). A medida que ésta se agrava, se produce un moteado intervenal de color verde claro. Es un síntoma único, pues se presenta sólo en esta carencia. Al ser severa, las nervaduras principales se mantienen de color verde oscuro y con áreas intervenales de color verde amarillento, hojas que engrosan y se doblan hacia arriba. La fruta tiene menor tamaño y no cambia su apariencia o calidad. Hay deficiencia cuando las hojas tienen menos de 25 ppm de manganeso (Mn). Cabe señalar que esta deficiencia no tiene influencia sobre la calidad y apariencia del fruto.

Corrección de Deficiencia

Se corrige con aplicaciones al suelo de sulfato de manganeso (MnSO4) a razón de 2 gr por metro lineal de plantación, o bien con quelato Mn- EDTA, en cobertera, cuando recién aparezcan los síntomas. Acidificar el suelo (cuando pH es mayor o igual a 7,5) con azufre (S), o con ácido sulfúrico (H2SO4) incorporándolo en el sistema de riego. No se debe pulverizar cuando la planta este en floración ya que produce daño.

Deficiency

The lack of this element presents with an interveinal chlorosis in the new leaves and in cases In severe cases, there is necrosis at the edges of the blade. This chlorosis could be caused by a zinc (Zn) or manganese (Mn) deficiency. This has little effect on the fruit, even when it is severe. Iron (Fe) contents less than 400 ppm in the sheet indicate deficiency.

Deficiency Correction

In alkaline pH soils, iron (Fe) deficiency is “induced” by excess carbonates. This is corrected by chelated fertigation of Fe-EDTA, Fe-DTPA and Fe-EDDHA. These sprays they must be done carefully so as not to damage the flowers and/or fruits. Alternatively you can acidify the soil with sulfur (S), or else by incorporating sulfuric acid (H2SO4) into the technical irrigation, to neutralize bicarbonates from irrigation water.

Deficiency

In the first stage of development, boron (B) deficiency causes symptoms similar to that of boron. calcium (Ca). Both appear in the new leaves, producing apical burn "tip burn" and fruit deformation, limiting root development. As this deficiency progresses, the leaves turn yellowish and both the growth and the size of the flowers are reduced, pollen production decreases and the fruit takes an oblique shape. Poor leaves have less than 25 ppm boron (B). It should be noted that in differential mode, if boron deficiency (B) it is moderate, interveinal chlorosis occurs; On the other hand, when this deficiency is calcium, it is keep the leaves green. It should be noted that strawberries are very sensitive to excess boron (B), therefore their application must be be supported by analysis.

Deficiency Correction

It is corrected by spraying the foliage with any boron-based product such as boric acid, mono ethanol amine and sodium octoborate applied through the borax product, 20 gr/100 lt of water, or well applying it to the ground, in cover (0.5 gr per linear meter), when the first symptoms. In flowering, given the susceptibility in this phenological period, the dose should be decreased of borax to 2 gr/100 lt of water.

Deficiency

Copper (Cu) deficiency is seen when new leaves turn pale green, uniform, with red areas. This symptom resembles that of iron (Fe) deficiencies, sulfur (S), manganese (Mn) or molybdenum (Mo). As this deficiency worsens, the area intervenal takes on a light green color, while the veins maintain their green color. Then it occurs a complete discoloration. The petioles and stems acquire a reddish color, which contrasts with the manganese (Mn) deficiency. that does not have this feature. Sheets with less than 3 ppm copper (Cu) (b.p.s) indicate deficiency. This deficiency does not affect the roots or the fruit.

Deficiency Correction

It is corrected with soil applications of copper sulfate (CuSO4) at a rate of 1 to 2 grams per meter linear, or Cu-EDTA chelate, in foliar application (0.075 - 0.15 g/lt).

It has not been proven that these elements are essential for the development of this plant; yes so outside, they would be in minimal quantities. The plant absorbs sodium (Na) and chlorides (Cl) slowly, since these would not be essential and probably as a self-protection mechanism to avoid salt damage. Leaves showing salinity damage contain higher concentrations to 0.80% sodium (Na) and 0.5% chlorides (Cl). When there are suspicions that the soil may be saline, it must be analyzed, as well as the water that will be used for irrigation. The result of these Analysis will help suggest corrective or palliative measures.

Sometimes berries are produced that, having a normal size and appearance, present a they fail in color and are unattractive and acidic, they also deteriorate quickly after of harvested. It is a physiological disorder whose origins cannot be attributed to a single causa, there are several conditions that can produce the presence of this disorder in the fruit.

Symptoms of Albinism

The skin has white areas, which can be easily broken and the internal color varies. between pink and white; In addition, its quality to be transported is affected. The above does the product loses value. The decrease in sugar when the berry ripens is the main cause of albinism in strawberries.

Correction of Albinism

To avoid this problem, a variety is suggested that adapts to the climate of the area in which it must be be luminous; care must be taken when applying nitrogen (N) since a high level can induce albinism. The flow of sugar to the fruit can be stimulated by spraying with hormones or by applying sources of phosphorus (P), potassium (K) and boron (B) to help translocation of photosynthates from the leaf to the fruit. Also applications of calcium (Ca) and boron (B) during preharvest decrease this disorder.