Capsicum is a plant that occupies an important place amongthe worldwide vegetable. In pepper culture technology, applying phytosanitary treatments is a technological link. It is very important to know the diseases and pests that attack this plant, and to apply the necessary plant protection products correctly and efficiently.

Diseases

CUCUMBER MOSAIC VIRUS IN PEPPER:

Dwarfing and narrowing of leaves in the pepper bush produced by the pathogen. The young plants that get attacked have a much smaller size, reaching only 50% of the height of a healthy plant. The internodes and branches of the plant are short, which results in a clumped appearance. The leaves are small, with a mosaic-shaped deformed limb (having healthy green tissue alternating with dark green or yellow tissue). On the attacked strains, sometimes grey or brown spots may be observed. The attacked fruits are small and deformed as well. The virus has a large circle of hosts, annual and perennial species, which are reservoirs of infection. Examples of hosts are: Shepherd’s Purse, Common Chickenweed, White dead-nettle, etc. The disease is transmitted by several species of aphids (plant lice) as well.

Prevention and control measures:

  • seedlings will be produced in areas where no other solanacées (tomatoes, eggplants, etc.) are grown;
  • destroying the host plants (weeds) in the crop and around the plot;
  • the pepper culture will be isolated from other crops of solanacées (tomatoes, eggplants, potatoes, etc.);
  • periodic insecticide treatments will be carried out to control insect pests;
  • eliminating attacked plants from the crop;
  • cultivation of resistant varieties;

Read: apple farming in Kenya: mitigating risks

BLEMISH STAIN DISEASE

It is produced by Tomato spotted wilt virus in pepper. This disease is manifested by the appearance of mosaic spots on the growth tips of the plants. Later on, the disease develops, and circular spots of brown, yellow or dark green appear on the plant. They evolve and cause necrosis of the attacked tissue. The attacked plants are smaller than the healthy ones and produce a smaller amount of fruit. The virus has a large circle of hosts, annual and perennial species, which creates reservoirs of infection throughout the year. The transmission of the disease is mainly caused by trips.

Prevention and control measures:

  • eliminating attacked plants from the culture;
  • destroying the host plants (weeds) in the crop and around the plot;
  • the pepper culture will be isolated from other crops of solanacées (tomatoes, eggplants, potatoes, etc.);
  • periodic insecticide treatments will be carried out to control insect pests;
  • cultivation of resistant varieties;

STUBBLE OF PEPPER (STOLBUR DISEASE IN PEPPER)

The disease is common to all plants in the Solanaceae family (tomatoes, peppers, potatoes, eggplants) and it is produced by a mycoplasma. This disease occurs throughout Europe, but the worst damage is reported in the eastern part of the continent. The leaves appear to be discoloured, the plant stagnates in growth, the flowers remain sterile or form small and deformed fruits. In severe cases, the disease causes a verticillium-like disorder, but in this case the conductive vessels are not turning brown. The source of infection is represented by the host plants (field bindweed, dodder, orache) or diseased plants (tomatoes, peppers, eggplants, potatoes) and is transmitted to healthy plants by several cicada species (insects).

Prevention and control measures:

  • destruction of host and segmented plants;
  • combating the insects that carry mycoplasmosis;
  • eliminating attacked plants from culture;
  • cultivation of resistant varieties;

BACTERIAL PATHOGENIC SPOTTING:

It is produced by Xanthomonas campestris bacteria, which often  attacks tomato crops as well. In a slight attack, the bacteria can cause the appearance of necrotic spots on the leaves, and a severe attack may cause the appearance of these spots on all the aerial organs of the plant. In sensitive varieties, stains are numerous, as they merge and produce defoliation of the plant. On the strains, the disease produces elongated cracks, which are browning. The attacked fruits have circular, wet, brown and harsh spots. Symptoms are evident in wet weather, when bacterial exudate flows from the wounds. This (the exudate) is installed on the seeds, in the soil and on the vegetal remains, ensuring the transmission of the bacteriosis.

Prevention and control measures:

  • the use of healthy seeds from certified sources;
  • cultivation of resistant varieties;
  • pepper culture should not be grown on land where tomatoes, aubergines, peppers or potatoes were planted;
  • chemical treatments with fungicides based on copper should be applied: Zeama bordeleza, Champ 77 WG, Copernico Hi Bio, Melody Compact 49 WG, Funguran OH 50 WP; Warning! Two consecutive treatments with the same product should not be applied.

Read: Why Hass Avocado is the new Cash Crop

THE GREY ROT

It is caused by Botrytis cinerea. The attack usually occurs in greenhouses and solariums, and in years with abundant rainfall, it can appear in the field. The most common symptom is sudden wasting of succulent tissues, such as young stalks and leaves. On the fruit, the attack occurs in the form of brown, damp spots, and in high humidity conditions, on the surface of the stains a greyish fuz appears.

Prevention and control measures:

  • chemical or thermal disinfection of the soil;
  • rational fertilization;
  • avoiding irrigation by sprinkling,
  • chemical treatments with Bravo 500 SC, Ortiva 250 SC, Rovral 500 SC, Teldor 500 SC, Switch 62.5 WG;

WILTING OF THE PEPPER PLANT (FUSARIUM)

Produced by the fungus Fusarium oxysporum. The occurrence of the disease is favoured by temperatures above 27-28ºC, high moisture in the soil and a slightly acidic pH. On the attacked plants, a leaf discoloration appears, followed by wilting. At first the plants suffer from temporary wilting, but in the end, the process is irreversible. On the fruit, moist spots of brown-grey appear. Fusarium is a vascular disease, the sections performed in the stems of the plant reveal an intense browning of the conducting vessels. The fungus lives in the soil, being widespread by water or agricultural tools and agricultural machinery. The fungus gets inside the plant through the root system, and in favourable conditions, it dries the plant in two weeks. The fungus also spreads through infected seeds.

Prevention and control measures:

  • chemical or thermal disinfection of soil in greenhouses, solariums, seedlings and seed treatment before sowing. For information on seed and soil disinfection click here;
  • avoiding relative humidity increase over 85% in greenhouses and solariums and avoiding soils where water stagnates;
  • use of varieties and hybrids resistant to fusarium;
  • seed treatment prior to sowing;
  • chemical treatments with Topsin 70 WDG and Topsin 500 SC. Prepare a solution of 0.05 – 0.1% (5 or 10 g per 10 litres of water) and spray each plant with 0.5 l (of the solution);

BLIGHT

It is  produced by Phythophtora infestans. Attack is common on leaves, fruits and seeds, rarely on stems and roots. On the upper side of the leaves, watery spots appear, which later become brownish. On the underside of the leaves, near the spots, a whitish puff appears. The affected tissues become brown and dry. The fruits appear brown, damp and soft. The seeds of the affected fruit contain the infectious mycelium of the fungus. When the disease attacks the strain, an annular, dark-green, then brown area appears at its base. After these symptoms occur, the wilt and drying of the plant takes place.

Prevention and control measures:

  • soil disinfection and seed treatment before sowing. For information on seed and soil disinfection click here;
  • rotation of crops (pepper is not cultivated after tomatoes, potatoes, eggplants, etc.);
  • avoid sprinkler irrigation;
  • avoiding soils where water stagnates;
  • chemical treatments with Bravo 500 SC, Acrobat MZ 90-600 WP, Ridomil Gold MZ 68, Equation PRO, Dithane M 45;

Read: Cabbage Farming in Kenya: New better varieties

THE MAIN PESTS

GREENHOUSE WHITEFLY (TRIALEURODES VAPORARIORUM)

The pest grows in greenhouse conditions throughout the year and in the field only during the summer. In the greenhouse, it can develop 3-6 generations when conditions are favourable. Adults and larvae colonize the leaves, often also the sprouts. After the attack, the leaves get etiolated, dry and fall off.

Control measures:

  • destruction of vegetal remains after the dissolution of the crop;
  • the disinfection of greenhouses and solariums before the establishment of a new crop;
  • treatments with Decis Mega 50 EC (0.25 l / ha), Actara 25 WG (0.2 kg / ha), Confidor Energy (1.3 l / ha), Mospilan 20 SG (1.5 g / 6 l water), Movento 100 SC;
  • the use of attractant traps;

RED SPIDER MITE (TETRANYCHUS URTICAE)

It can develop 6-10 generations per year and it winters in the adult stage, especially as a female (males are generally less rare), under the scuffed bark of trees, under the fallen leaves, on dry weeds or in the superficial soil layer, etc. The attacked leaves dry up and fall, defoliations being recorded, which can sometimes contain 80-100% of the leaf count. As a result of the attack, there is a halt in the growth of the sprouts and a premature ripening of the fruits.

Control measures:

  • treatments with Vertimec (1 l / ha), Nissorun 10 WP (5 g / 12 l water), Envidor 240 SC, Millbeknock EC;

APHIDS

They are polyphagous species that migrate from one plant to another or from one species to another. They grow on any kind of plant or tree, and then migrate and attack crops. They appear as a colony on the underside of the leaves, on the flowers or inflorescences and on young sprouts. Insects prick the plant and suck the cell juice, causing a stress on the plant. In the event of a severe attack, aphids can cause the death to of the plant.

Control measures:

  • treatments with Decis Mega 50 EC (0.2 l / ha), Confidor Energy (0.6 l / ha), Mospilan 20 SG (1.5 g / 12 l water), Actara 25 WG;
  • the use of attractant traps;

THE BROAD MITE (POLYPHAGOTARSONEMUS LATUS)

It is a polyphagous species, commonly found in  protected areas (greenhouses and solariums). It attacks the lower part of the leaves, floral blooms and fruits. The attacked organs turn yellow and deform.

Control measures:

  • treatments with Nissorun 10 WP (5 g / 12 l water), Vertimec 1.8 EC (10 m / 10 l water), Envidor 240 SC;

THRIPS

These are small insects, hardly visible to the naked eye, attacking a large number of crop plants. They colonize the tops, flowers, and leaves of the plant, causing flower abortions and plant dwarfism. They also transmit a series of viruses.

Control measures:

  • treatments with Actara 25 WG, Mavrik 2 F, Karate Zeon 50 CS, Decis Mega 50 EW;
  • the use of attractant traps;

THE ROOT-KNOT NEMATODES (MELOIDOYNE SPP)

It  has several generations per year. Immediately after hatching, the larvae flow through the soil in search of roots. They enter easily into the radicular system, where they secrete a toxin that causes hypertrophy of the tissues, blocking the conductive vessels of the affected areas.

Control measures:

  • Disinfection of soil with Force 1.5 G (15 kg / ha) or Basamid Granules;
  • use of certified seeds;
  • cultivation of resistant varieties;

MOLE CRICKET (GRYLLOTALPA GRYLLOTALPA)

It has an omnivorous diet, feds with vegetal substrates, live prey (earthworms and various larvae) or insect corpses. The damages produced are direct, by eating the root system of the plants (cutting off the strains of the plant when it is rising or it is replanted). They bring up to the surface of the soil the germinated seeds of plants, or even young, small plants. The attacked ones wither and bend over to the ground.

Control measures:

  • chemical treatments applied to the soil