Impact of Cropping Patterns on seed bank and emergence of Orobanche in infested field.
Date
2023-08-14
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Amrit Campus
Abstract
Orobanche is a genus of more than 200 species of parasitic herbaceous plants in the family
Orobancheaceae that cause damages to the important vegetables and field crops in many parts of
the globe including Nepal. Orobanche is a problematic parasitic weed in tomato and brinjal fields
of Lalbandi, a major tomato growing areas in Nepal. Orobanche emergence in the early sown six
tomato and one brinjal fields, and in late sown six tomato and one brinjal fields were recorded
along with the past history of each fields. The soil samples from these seven early sown and seven
late sown fields were collected for the Orobanche seed bank study. The Orobanche seed bank
study was conducted using the flotation technique of Ashworth (1976) with some modification
(Acharya et al., 2003).From this study on Orobanche emergence at early and late sown tomato
and brinjal fields, it can be concluded that the severity of the parasitic weed in a field cannot be
ascertain with the Orobanche shoot emergence alone.
The Orobanche seed bank study gave the real picture of parasitic weed infestation in the field. In
the early sown tomato fields F7,Orobanche seeds/100g soil was significantly lowest, and this filed
had a history of only cultivation of cucumber for last 5 years with no winter crops and tomato was
grown only after five years as winter crop. This clearly indicates that gapping of tomato cultivation
reduces Orobanche seed bank in the fields. Similarly, reduction in Orobanche seed bank was also
recorded in early sown fields like F1 and F4, where hand pulling of Orobanche shoot was in
practice, as well as have the field history with the intervention of crop rotation with lentil and
chickpea, respectively. Among the late sown fields of tomato and brinjal, Orobanche
seeds/100gsoil was found to be less than in early sown fields. The Orobanche seeds/100g soil in
late sown fields was significantly (P=0,05) low in F5 and F1 which had a history of growing only
paddy for last 3 years and 2 years, respectively (with no winter crop), and then tomato was
cultivated as winter crop after 3 and 2 years, respectively. This indicated that gapping the
cultivation of host plants for some years also helps in reducing the seed bank of parasitic weeds.
Beside this when Orobanche seed bank/100 g soil was compared between the paddy and maize
fields of early and late sown tomato/brinjal fields, most of the paddy fields were recorded to have
less Orobanche seed bank than at the maize fields. From the Orobanche seed bank study of early
and late sown tomato and brinjal fields it can be concluded that late sowing helps in reducing the
Orobanche seed bank in soil.
Description
Keywords
Orobanche, cropping pattern, seed bank and quantitative estimation.