No abstract

The plant species belong to the family Loranthaceae (mistletoe family) are hemi parasites. Dendrophthoe falcata is a large bushy evergreen stem hemiparasite. It can capture food from the host trees by means of penetrating roots called the haustoria. This epiphytic parasite found generally on various host plants in large amounts worldwide and causes much damage to economical cultivated plants and also grown on different host plants throughout India. As hemiparasite it is associated with tropical trees specifically the mango trees and rarely few timbers yielding trees. It has been reported to have increased its host range and found growing on varieties of trees. The species of Dendrophthoe falcata commonly known as Loranthus are common parasitic flowering plants occur all over India and cause severe damage to the field crops. However, comprehensive reports on the occurrence of this parasite, host range, effect on crop production, management practices are not available in the country. Under these circumstances the present study was undertaken to identify the species of Loranthus attacking a fruit yielding crop mango (Mangifera indica) cultivated in and around Vizianagram District, Andhra Pradesh to observe their parasitic relationship with their host plants.

A field trial was carried out in the Kharif seasons 2007 at Junagadh Agriculture University (JAU), Junagadh, Gujarat to evaluate the impact of integrated approach of weed management on rain fed cowpea. It was found that selection of appropriate herbicides and its application in combination with cultural practices at critical period of weed growth was key factor to get elevated yield in rain fed cowpea. Till date most accepted practices among cowpea growers is single application of herbicides or go for cultural practices one hand weeding (HW) + one inter cultural (IC) at 20-25 days after sowing (DAS). This was not found sufficient to manage weeds and negatively distress the growth parameters and ultimately resulted in loss of one fourth crop yield compared to that weed free treatment.2 and (quizalofop-ethyl + 1 HW + 1 IC) very effective in weed control and had positive impact on plant height, plant spread, number of branch per plant, number of pods per plant and number of seeds per pods. These treatments were as good as weed free plot. These integrated weed management treatments gave broad spectrum weed control and higher gross, net return and B:C ratio. By adopting appropriate weed management practices farmer can get 3000 to 4000 net increase in return over the other treatment. So integrated weed management is better option and cowpea grower combine cultural practices with suitable pre and post herbicides like as pendimethalin, quizalofop-ethyl and imazethapyr to get similar return as weed free plot.

The hemiparasitic plant, Dendrophthoe falcata (L.f.) Etting. known as Loranthus is a stem parasite, mostly prefers Mangifera indica L. (mango) as its host. Remarkable damage of the mango crop due to the adverse effect of Loranthus was identified in the field area. The occurrence and host preference of the D. falcata was systematically studied at eight field sites of Vizianagaram District. The vegetative, reproductive and parasitic characteristics of D. falcata were recorded periodically. The effective management strategies to control Loranthus were not employed in the study area because of the lack of knowledge on the host-parasite interaction. Keeping in mind, the investigation was conducted (October 2018 to June, 2019) in mango fields of Vizianagaram District of Andhra Pradesh to explore the biology, the host specificity, the occurrence, the pollination, the bird-host-parasite interaction and the effective control methods of D. falcata.

A b s t r a c t A r t i c l e I n f oTrianthema portulacastrum L., commonly known as desert horse purslane is a member of Aizoaceae, interfere with many economic crops and treated as one of the serious weed in India and around the world. It is a native plant of South Africa but widely distributed in India, Sri Lanka, Pakistan and many parts of the world. It has become a noxious weed due to competition for yields in many crops and causing significant reduction in the yield. For instance, its infestation in cotton, maize and direct-seeded rice reduce crop yields by 32-60%, up to 60-70% infestation of this weed has been reported in pigeon pea and soybean fields and 80-90% in maize and brassica fields. The common weed control methods such as cultural practises, mechanical and herbicide treatments does not consider for the effective management of this weed due to their failures. Recently, the successes of Biological control agents over many herbs and alien weeds attracted researchers with their eco-friendly tactics. Therefore, a systematic field study was conducted for preliminary screening of natural enemies against horse purslane weed which would be an effective biocontrol agent after extensive work. An ascomycetes fungus, Gibbago trianthemae Simmons was isolated from parasitized leaves of horse purslane and the identity was confirmed by relevant literature and the biocontrol potential of the pathogen evaluated.