**6.2** *Ascochyta***: blight**

*Ascochyta* blight (*Ascochyta pisi*) black spot symptoms on pods result in the production of round tan-colored sunken spots bearing dark margins. Pycnidia develop in the centers of such spots on pods (**Table 1**).

### **6.3** *Phytophthora***: late blight**

Tomato (*Solanum lycopersicum,* solanaceae) is one of the most important vegetable crops. In the last couple of the years, the disease has become one of the most devastating threats to the cultivation of tomatoes in eastern Uttar Pradesh [15, 16]. Initial disease symptoms appeared in the form of irregular; water-soaked and light brown lesions on leaves which are normally covered with white cottony mycelial growth on the lower side of leaves. Water-soaked brown lesions expanded rapidly on stem and green fruits. Infected green fruits of tomato usually developed olivaceous, brown-colored leathery, and hard structures. All infected fruits eventually fall of from the plants and they were neither fit for marketing nor human consumption. Microscopic studies of the colonized pathogen on potato slices revealed hyaline, coenocytic, branched hyphae, and aseptate sporangiophores with lemon-shaped, papillate sporangia. Sporangia dimensions were 32 ± 6.3 × 20 ± 4.9 μm, with a length to width ratio of 1.6. On the basis of morphological characteristics and sporangia size, the pathogen was confirmed as *P. infestans* (**Figure 2**) [17].

#### **6.4** *Colletotrichum***: fruit rot**

Chili (*Capsicum annum*, solanaceae) is an economically important spice crop, widely grown in India. *Colletotrichum* sp. is an anamorphic fungal genera ranked in 8th position among top 10 fungal plant pathogens in the world. Infected fruits showing typical anthracnose symptoms of sunken necrotic lesions with a black dot like acervuli in concentric rings collected and collected fruit samples were examined under a light transmission microscope. Anthracnose (*Colletotrichum lindemuthianum*, *C. orbiculare*) symptoms appear on immature pods. Sunken cankers with lighter or gray central areas of about 5–7 mm size are seen. The spots on vegetable pods are enlarged and produce tiny black acervuli in the centers which in humid conditions ooze viscous droplets consisting of a mass of pinkish spores. Pure culture *Postharvest Diseases of Vegetable Crops and Their Management DOI: http://dx.doi.org/10.5772/intechopen.101852*

#### **Figure 1.**

*Typical symptoms of Sclerotinia white rot and culture plate. (A) Indian bean, (B) Indian bean, (C) French bean, (D) pea, (E) pea, (F) brinjal, (G) tomato, (H) bottle gourd, (I) PDA culture plate.*


#### **Table 1.**

*Postharvest diseases/pathosystem of leguminous vegetable crops.*

**Figure 2.**

*Typical Symptom of* Phytophthora *blight on tomato fruits and Sporangia. (A) Tomato, (B) sporangia.*

#### **Figure 3.**

*Typical symptoms of* Colletotrichum *fruit rot (anthracnose), culture, and conidia. (A) Chili, (B) cowpea, (C) bottle gourd, (D) bottle gourd.*

of the pathogen isolate was established on PDA by the hyphal tip method. Under the light microscope, one-celled, smooth-walled hyaline falcate, tapered ended conidia (16–26 × 3–4 μm) and acervuli with numerous setae (15–27 × 2–5 μm), were recorded. In this respect, this documentation will play an important role for better understanding of the pathogen and formulation of disease management strategies for the prevention of pre and postharvest crop losses under changing climatic scenarios (**Figure 3**).
