Root rot of carrot

carrots are a major problem and can lead to significant postharvest losses Several different fungal pathogens cause similar symptoms, which are collectively [...] collectively known as black spot diseases. When carrots are stored during winter, diseases on the carrot roots can continue to develop during storage. Alternaria [...] and eventually cover the entire surface of the carrot. The affected areas are firm, shallow, and clearly visible. Under certain conditions, an olive-green

Gummy stem blight

veins) or the hair bases. Stems are infected through wounds and by the infected leaves through the petioles. Fruits are infected through the flowers. The [...] newly produced ascospores are dispersed by air and the conidiospores by water drops, tools and hands of workers. The ascospores are the main source of dispersal

Crazy roots, hairy roots, crown gall

takes place via wounds. After infection, galls are formed which break open, releasing many bacteria. These are dispersed by rain and wind and by humans and [...] General Rhizobium bacteria are soil bacteria that fix nitrogen after becoming established inside root nodules of legumes. Additionally, pathogenic Agr [...] root growth. All four species cause the growth of galls on the stems, which are first white and later turn brown. Only Rhizobium radiobacter causes galls

Brown root rot, corky root rot

rot and corky root rot. Damage symptoms The first signs of this disease, are poorly looking plants in localized areas of the greenhouse or field. The affected [...] of leaves and premature defoliation may occur. Looking at the roots, there are three different symptoms. Small feeder roots rot completely. Small roots may [...] tomato and other hosts. Several alternate hosts in outdoor cropping systems are known: pepper, melon, aubergine, squash, spinach and safflower. The disease

Fusarium head blight or scab

conidia are produced that further spread the disease. Gibberella zeae (Fusarium graminearum ) primarily infects the older, lower leaves. The spores are dispersed [...] Fusarium is widespread and can infect a range of host crops. Many species are considered weak pathogens and can only infect wounded or stressed host plants [...] splashing rain drops or wind. On the infected ears, the typical pink spores are produced which may further spread the disease. Ascospores of Gibberella zeae

Grape powdery mildew

powdery patches on the affected plant parts. All the above ground plant parts are susceptible to infection. Powdery growth on both the surface of the leaves [...] plant to plant. Warm temperature with enough humidity and cloudy weather are favourable conditions for the pathogen severity. Management Sanitation and

Bacterial soft rot, bacterial stem rot

normal colour. On the fruits, lesions first are small and sunken, water-soaked and light to dark brown. They are adjacent to wounds and natural openings at [...] Pectobacterium carovora can also be found as secondary pathogen in plants that are infected by other pathogens. The bacteria that causes black leg in potato

Leaf stripe

first, second and third leaf and subsequently on other leaves. Yellow stripes are formed at the base of the leaf and the leaf sheath. They gradually extend [...] primary infection. The fungus spreads from the seed into the seedling. Conidia are produced on the infected leaves when humidity is high and wind-dispersed to [...] seedling emergence is critical for infection. Soil temperatures below 12 °C are most conducive for this disease and infection does not occur at soil temperatures

Cotton bollworm

brown. Full grown larvae are 30 to 40 mm long. The first instars are the most mobile, and move like loopers. The caterpillars are often aggressive and c [...] drop off. In legumes, flowers are attacked, and seed pods may be pierced. Life cycle and appearance of Cotton bollworm Eggs are deposited individually on young [...] flowers, fruits or on leaves. They are almost spherical with a flattened base and a diameter of about 0.5 mm. They are at first a shiny yellowish white,

Grape mealy bug

bunches are not suitable for making raisins. Life cycle and appearance Mealy bugs are found in crevices of stem, on leaves and berries. Mealy bugs are pinkish [...] and eggs are orange in colour. First instar nymphs also called as crawlers are mobile, start sucking the plant sap and form colonies and are orange in [...] in colour. Female mealy bugs are abundantly found causing damage to the crop while males are very rare. Females reproduce partheno-genetically without mating