Solanum nigrum, a new host for powdery mildew disease of Capsicum annuum in the Madurai district of Tamil Nadu, India
In October–November 2004, a severe outbreak of powdery mildew disease incited by Leveillula taurica was observed on Capsicum annuum (cv. K2) (chilli) and caused yield loss up to 80%. A similar type of symptom was also recorded on Solanum nigrum grown in and around chilli fields. Based on the morphological characteristics and cross infectivity, it has been confirmed that the powdery mildew pathogens from C. annuum and S. nigrum are the same. The pathogen from C. annuum could infect S. nigrum and vice versa. Other cultivated plant species were not infected. This might be due to the probable occurrence of physiological races. This is the first report of this organism causing powdery mildew in S. nigrum in the Madurai district of Tamil Nadu. The ability of L. taurica to infect the native host S. nigrum is particularly important because this host plant might serve as an inoculum reservoir for adjacently cultivated C. annuum.
Common Pests and Diseases of Medicinal Plants and Strategies to Manage Them
Medicinal plants are known to Indian traditional healers since time immemorial. The plants were collected, by and large, from the wild and were used in many preparations of wellness products. India is endowed with diverse group of medicinal plants accounting for more than 8000 species which are being used in more than 10,000 herbal products. Ninety percent of herbal industry’s requirement of raw materials is meted out from the natural ecosystem – forests – resulting in ruthless exploitation and destruction of its natural habitats (Mathivanan et al. 2016). As one of the measures to conserve the precious species, commercial cultivation began which inadvertently brought the problem of pests and diseases leading to crop loss of various magnitudes. This chapter will discuss on major pests and diseases of some important medicinal plants like noni (Morinda citrifolia L.), glory lily (Gloriosa superba), makoi (Solanum nigrum), medicinal coleus (Coleus forskohlii), senna (Cassia angustifolia) and ashwagandha (Withania somnifera). Medicinal plants being used in health-care system and chemical methods of management of pests and diseases are becoming obsolete. It is a must that non-chemical, eco-friendly safer methods of management are essential which are also being discussed in this chapter.
Assessment of some agro-technological parameters of cactus pear fruit ( Opuntia ficus-indica Mill . ) in Morocco cultivars
Cactaceae had always attracted attention by their strange shapes and important adaptability supporting extreme conditions. For this reasons, Fruit traits were measured on 13 cultivars growing in different locations in Morocco. Results show significant differences between the cultivars. The source of this variation was probably genetic without excluding the geographic effects. The Tamri, Berkan, Ait Baha cultivars showed small fruit dimensions and weight. In contrast, Sidi-Ifni M, Nador, Mohammedia and Ben Guerir were greater than 100 g by fruit. Sidi-Ifni M, Hoceima, Mohammedia and Nador, although larger, contained few seeds, about 200 seeds per fruit; while Tamri, Ait Baha, Safi, Meknes and Tafraout contained over than 230 seeds per fruit. High levels of juice about 62 ml/100 g pulp were obtained with Sidi-Ifni M, Nador, Mohammedia and Ben Guerir cultivars. Total sugars of the 13 cultivars were quite similar and pH was low in Tamri and close to neutrality in the rest of cultivars. Therefore, oil extracted from Opuntia ficus-indica seeds constituted 13.6% of the whole seed. Thin-layer chromatography in conjunction with gas-liquid chromatography-mass spectrometry revealed a relatively high degree of unsaturation, 83.32% and 16% for saturated fatty acid, with a linoleic acid content of 63.66% followed by oleic 18.34%, palmitic 12.84% and stearic acid 2.81%. Based on these results, O. ficus-indica seed oil appears to be a good potential source of edible oil for human and (or) animal consumption. Our investigation describes that Tamri and Tafraout cultivars are not really a commercial viable fruit due to low total soluble solids value and highest seeds number per fruit. Against Mohammedia, Sidi Ifni M and Nador cultivars proved to have the highest fruit weight, very good total soluble solids value and low number of seeds, these cultivars can therefore be planted for both fruit production and for harvesting of cladodes for animal feed.