Common pests and diseases in blueberry

Nitrogen Deficiency

Nitrogen deficiency is usually first noticed in the older leaves, which appear pale and weakened. Over time, the plant loses vigor, reduces its production, and becomes more susceptible to pests and diseases.

Typical symptoms:
• Yellow or pale green lower leaves (chlorosis).
• Thin stems and reduced growth.
• Small leaves and premature drop.
• Early and forced flowering.
• Poor fruit production or grains with low protein content.

Nitrogen deficiency progresses gradually, beginning with mild signs and reaching critical stages if not corrected promptly.

Developmental stages:
• Initial: Mature leaves are lighter than normal.
• Intermediate stage: Yellowing progresses from the lower leaves to the upper ones.
• Advanced: Stems and veins take on a reddish or purplish hue.
• Final: Generalized chlorosis, leaf necrosis, and premature wilting.
• Final consequence: sharp reduction in yield and even death of the plant.

Phosphorus Deficiency

Phosphorus is relatively mobile in the plant, so symptoms usually appear on older leaves first, although overall development is also compromised.

Typical symptoms:
• Slow growth and stunted development.
• Older leaves with dull, dark green tones.
• Appearance of purple, reddish, or bluish pigmentation, especially on the undersides of leaves and stems.
• Poorly developed root system with few lateral roots.
• Delayed flowering and ripening.
• Small fruits and lower yield.

Phosphorus deficiency directly affects the plant's energy and vitality, making it weak and less able to withstand stress.

Developmental stages:
• Early: Older leaves with darker green than normal.
• Intermediate stage: Purple or reddish pigmentation on stems and veins.
• Advanced: Limited growth, short, and sparsely branched roots.
• Final: reduced flowering, poorly formed fruits and low productivity.

Iron Deficiency

Unlike other nutrients, iron deficiency first manifests in young leaves, as the plant cannot mobilize it from older tissues. This helps distinguish it from deficiencies such as nitrogen or magnesium.

Typical symptoms:
• Chlorosis (yellowing) in young leaves, with visible green veins.
• Growth of new shoots is halted.
• Reduction in leaf size.
• In severe cases, leaves turn almost white with necrosis at the edges.
• Decreased flowering and fruit set.

Iron deficiency develops rapidly in calcareous or poorly drained soils, first affecting the newer areas of the plant and later compromising the entire foliage if not corrected.

Developmental stages:
• Early: Young leaves become lighter, retaining green veins.
• Intermediate stage: More intense yellowing, chlorosis spreading to the entire leaf.
• Advanced: Leaves with almost white tones, very limited growth.
• End: appearance of necrosis, leaf drop, and severe loss of yield.

Potassium Deficiency

Unlike iron, potassium is mobile in the plant, so symptoms first appear on older leaves. The most characteristic appearance is marginal scorching (marginal necrosis), which progresses inward.

Typical symptoms:
• Yellowing (chlorosis) on the edges of lower leaves.
• Marginal necrosis, a "burnt" appearance.
• Leaves curled downward or with dark spots.
• Weak stems and thin buds.
• Small, deformed, or poorly colored fruits.
• Decreased resistance to drought and disease.

Potassium deficiency develops progressively and directly affects crop yield and quality, even if the plant survives.

Developmental stages:
• Initial: marginal chlorosis on older leaves.
• Intermediate stage: necrosis on edges and tips, progressing inward.
• Advanced: Leaves with dry, brittle edges, premature drop.
• Final: Thin stems, sparse flowering, poorly developed fruit, and increased sensitivity to stress.

Magnesium Deficiency

Magnesium deficiency causes interveinal chlorosis, beginning in older leaves and progressing to newer leaves if not corrected.

Typical symptoms:
• Yellowing between the veins of older leaves (interveinal chlorosis).
• Leaf margins remain green while the center turns yellow.
• Small or wilted leaves.
• Loss of vigor and slow plant growth.
• In severe cases, leaves show necrotic spots and premature leaf drop.
• Decreased fruit and seed production.

Magnesium deficiency progresses gradually and affects the plant's photosynthetic capacity and overall metabolism, compromising yield and harvest quality.

Developmental stages:
• Initial: interveinal chlorosis in older leaves, while the veins remain green.
• Intermediate stage: more intense chlorosis and the appearance of necrotic spots.
• Advanced: leaves with dead tissue and premature leaf drop.
• Final: growth stopped, small or deformed fruits and loss of yield.

Boron Deficiency

Boron deficiency first manifests in young shoots, flowers, and developing fruits due to their limited mobility within the plant.

Typical symptoms:
• Flower abortion and flower drop.
• Deformed, dry, or necrotic fruit.
• Dead or deformed terminal shoots.
• Small, curled, or chlorotic young leaves.
• Weak, brittle stems.
• Reduced root growth in young plants.

Boron deficiency develops rapidly in young tissues and reproductive organs. If left uncorrected, it compromises fruit and seed production, seriously affecting crop yield and quality.

Developmental stages:
• Early: Small, curled young leaves, shoots with limited growth.
• Intermediate stage: Flower and young fruit abortion, organ deformation.
• Advanced: Necrosis in fruits, death of terminal shoots.
• End: massive drop of flowers and fruits, significant reduction in the harvest.

Calcium Deficiency

Calcium deficiency first affects actively growing parts. It is especially recognized in fruit quality problems such as blossom end rot in tomatoes and peppers, or bitter pit in apples.

Typical symptoms:
• Deformed, curled, or dry-tipped young leaves.
• Necrosis on the edges and tips of new leaves.
• Deterioration of fine root and shoot growth.
• Appearance of dark, sunken spots on fruit (e.g., blossom end rot in tomatoes).
• Soft or watery texture on fruit and leaves.

As a non-mobile nutrient, calcium deficiency develops in a localized manner, primarily affecting growing organs, with a strong impact on production quality.

Developmental stages:
• Initial: mild deformations in young leaves and shoot tips.
• Intermediate stage: necrosis at leaf tips and flower abortion.
• Advanced: sunken spots on fruit, blossom end rot.
• Final: loss of commercial value of the crop and reduction in yield.

Sulfur Deficiency

Sulfur deficiency can be confused with nitrogen deficiency, but it affects young leaves rather than older ones.

Typical symptoms:
• Yellowing (chlorosis) in young leaves and new shoots.
• Delayed overall plant growth.
• Thin, brittle stems.
• Delayed flowering and ripening.
• Lower protein and oil content in grains and seeds.

Sulfur deficiency develops progressively and, if not corrected, limits crop quality and yield, especially in legumes, cruciferous crops, and cereals.

Developmental stages:
• Early: Young leaves with a uniform pale green color.
• Intermediate stage: More intense chlorosis in shoots, slow growth.
• Advanced: Thin stems, small, deformed leaves.
• Final: Marked reduction in flowering, protein-poor seeds, and lower total yield.

Ring Rot Or Disease

Ring rot or disease caused by Phytophthora megasperma in carrot is characterized by a progressive decomposition of the roots and neck of the plants. Symptoms generally begin in the roots, spreading towards the stem and causing general weakening of the plant.

- Discoloration and watery Taches on the roots
- Appearance of a ring of rot around the neck of the plant
- Necrosis of root and stem tissues
- Wilting and yellowing of foliage
- Plant collapse in advanced stages of infection

Carrot Weevil

The carrot weevil causes a disease in carrots that can significantly affect their quality and yield. The main damage is caused by larvae feeding on the roots, which can lead to deformation, stunted growth and, in severe cases, death of the plant. Affected carrots show visible symptoms on both the aerial part and the roots.
- Holes and tunnels in the roots.
- Deformations and scars on carrots.
- Wilting and chlorosis of the leaves.
- Delay in plant growth.
- Loss of vigor.
- Death of young seedlings.

Carrot Scab

Carrot scab, caused by Streptomyces scabies, is a disease that primarily affects the appearance and quality of carrot roots. Infected roots develop superficial lesions that can become rough and warty, decreasing the commercial value of the crop.
- Rough lesions and scabs on the surface of the carrots.
- Brown discoloration in affected areas.
- Deformations and cracks in the roots.
- Warty and rough appearance.
- Reduction in plant growth and vigor.
- Loss of commercial quality of carrots.

Thrips

Frankliniella occidentalis infestation on carrots causes the disease known as thrips, which can result in significant damage to both the quality and quantity of the crop. Thrips feed by sucking cellular juices from the leaves and roots, which can weaken the plant and affect its development.
- Silvery or discolored Taches on the leaves.
- Dotted and wrinkled feeding areas.
- Distortion and malformation of the leaves.
- Reduction in the vigor and growth of plants.
- Healing on the surface of the roots.
- Delay in the development of carrots.

Brown Crown And Root Rot

Brown crown and root rot, caused by Rhizoctonia solani, is a devastating disease of beet. This fungus infects the underground parts of the plant, causing a series of symptoms that affect both the development and yield of the crop. The disease initially manifests itself as brown Taches at the base of the plant, which progressively expand. The roots and crown are affected, showing dark brown decay and tissue collapse. Affected plants usually show stunted growth and may die if the infection is severe. The roots become soft and give off an unpleasant odor as the rot progresses.

- Brown Taches at the base of the plant
- Dark brown decay on roots and crown
- Stunted growth
- Death of severely infected plants
- Soft roots with an unpleasant odor

Bad Vinous

Wine disease, caused by Rhizoctonia violacea, severely affects beets, compromising both their development and productivity. The disease initially manifests itself as purple Taches on the roots and crown of the plant, which expand and darken over time. These Taches are the result of the breakdown of plant tissue, which turns brown and then black as the disease progresses. Affected plants show poor growth, wilting and, in severe cases, may die.

- Purple Taches on the roots and crown
- Decomposition of plant tissue
- Darkening of Taches to brown and black
- Poor plant growth
- Wilting
- Death of severely affected plants

Phomosis

Phomosis, caused by Phoma betae, is a disease that severely affects beets, compromising their quality and yield. The first symptoms are seen as small dark Taches on the leaves and crown of the plant. These Taches expand and become necrotic, causing sunken, discolored lesions. The infection extends to the roots, where black or brown Taches can be seen, which deepen and cause internal rot. Infected plants show delayed growth and wilting, especially in high humidity conditions.

- Small dark Taches on the leaves and crown
- Sunken and discolored lesions
- Black or brown Taches on the roots
- Internal root rot
- Delayed growth
- Wilting in high humidity conditions

Sclerotium Disease, Southern Blight Or Southern Blight

Sclerotium disease, southern blight or southern blight caused by Sclerotium rolfsii in beets manifests itself with a series of distinctive symptoms. Initially, infected plants show wilting and chlorosis of the lower leaves, which then progresses to the upper leaves. The roots and the base of the stem may show brown lesions and soft rot, accompanied by a layer of white mycelium and the presence of sclerotia in the infected tissue.

- Withering and chlorosis of the lower leaves.
- Brown lesions on the roots and base of the stem.
- Soft rot at the base of the stem.
- Presence of white cottony mycelium in the soil and infected tissues.
- Formation of brown sclerotia in the affected tissues.
- General decay of the plant.

Ramularia

Ramularia caused by Ramularia betícola significantly affects beets, manifesting first in the lower leaves and progressing to the upper ones. Early signs include small chlorotic Taches that develop into dark brown necrotic lesions, surrounded by a yellow halo. These lesions can coalesce, causing significant defoliation and reducing photosynthesis and crop yield. Under severe conditions, plants may experience widespread wilting and premature death.

- Small chlorotic Taches on the leaves.
- Dark brown necrotic lesions with a yellow halo.
- Coalescence of lesions causing defoliation.
- Reduction of photosynthesis.
- Generalized wilting.
- Premature death of the plant.

Alternariosis

Alternariosis caused by Alternaria tenuis in beet is characterized by the appearance of dark Taches on the leaves, which gradually enlarge and become necrotic. These Taches can coalesce, resulting in premature defoliation that affects photosynthesis and, therefore, plant growth and yield. Severely affected plants may show symptoms of wilting and poor overall development, compromising the quality and quantity of the harvest.

- Dark Taches on the leaves.
- Necrotic lesions that enlarge.
- Coalescence of stains.
- Premature defoliation.
- Reduction of photosynthesis.
- Wilting and poor development of the plant.

Powdery Mildew

Powdery mildew in table beets is a disease that mainly affects the leaves, reducing photosynthesis and weakening the plant. Symptoms include white powdery Taches covering the surface of leaves and other aerial organs. Infected leaves may turn yellow and drop prematurely, which decreases the plant's ability to produce and store sugars, affecting crop yield and quality.
- White powdery Taches on leaves and stems.
- Yellowing and premature leaf fall.
- Reduction of photosynthesis.
- General weakening of the plant.
- Decrease in crop yield and quality.

Rust

Beet rust caused by Uromyces betae is a disease that mainly affects the leaves, decreasing photosynthetic efficiency and weakening the plant. Severe infections can significantly reduce crop yield and quality.
- Appearance of orange to reddish pustules on the surface of the leaves.
- Yellowing and death of affected leaves.
- Reduction of photosynthesis and general weakening of the plant.
- Development of lesions that can merge, covering large areas of the leaves.
- Premature fall of infected leaves.