Al-Sadi A.M.,Sultan Qaboos University |
Al-Raisi I.J.,Directorate General of Agriculture and Livestock research |
Al-Azri M.,Directorate General of Agriculture and Livestock research |
Al-Hasani H.,Directorate General of Agriculture and Livestock research |
And 4 more authors.
Journal of Phytopathology | Year: 2012
In 2004, severe powdery mildew infection on peach occurred in Al-Jabal Al-Akdhar, Oman, and resulted in substantial yield losses to growers. This study was conducted to investigate occurrence, causal agents, genetic diversity and efficacy of azoxystrobin in management of this disease. Powdery mildew was observed on all farms and peach trees in Al-Jabal Al-Akdhar. Disease symptoms were first observed on shoots in April, followed by appearance on fruits. Disease severity reached its peak between May and June. Morphological and molecular identification of 22 powdery mildew isolates indicated that all belong to Podosphaera pannosa. Podosphaera pannosa reproduced the same symptoms upon inoculation on peach leaves. Amplified fragment length polymorphisms analysis of 35 isolates of P. pannosa from five different villages using four primer pair combinations produced 688 polymorphic loci and 35 different genotypes. Populations of P. pannosa were found to have low levels of gene diversity (H = 0.1858), which suggests that P. pannosa has been recently introduced into Al-Jabal Al-Akdhar. Analysis of molecular variance showed low levels of genetic differentiation among populations from the different villages, implying the introduction of P. pannosa into the different villages via common sources as well as frequent movement of pathogen inoculum among the different villages. Evaluating the efficacy of azoxystrobin showed that azoxystrobin is as efficacious as thiophanate-methyl in managing the disease, with sulphur being the least efficacious. The study is the first to report the presence of P. pannosa in Oman. Also reported are its genetic diversity and its management under commercial conditions. © 2012 Blackwell Verlag GmbH.
Al-Saady N.A.,Sultan Qaboos University |
Nadaf S.K.,Directorate General of Agriculture and Livestock Research |
Al-Subhi A.S.,Sultan Qaboos University |
Al-Hinai S.A.,Directorate General of Agriculture and Livestock Research |
And 4 more authors.
International Journal of Agriculture and Biology | Year: 2014
A wide range of indigenous varieties of different legume crops has been available in Oman since time immemorial, as these crops are preferred by farmers for their cooking quality and affinity. This paper focuses on the outputs of a collecting expeditions of indigenous legume germplasm for their conservation to avoid extinction due to new emerging edaphic (temperature, salinity, drought etc.) and biotic (insects, pests, diseases etc.) stresses being faced as a result of climate change and to ensure food security of the country. In all, 303 seed samples of land races/accessions in nine legume crops were collected from seven governorates, 187 of which were from seven food legume crops collected from 110 sites. The highest number of accessions was found in cowpea (Vigna unguiculata subsp. unguiculata) (64) followed by faba bean or broad bean (Vicia faba) (41), field peas (Pisum sativum) (27), mung bean (Vigna aureus) (25), chickpea (Cicer arietinum) (13), lentil (Lens culinaris) (11) and pigeon pea (Cajanus cajan) (6). South Batinah had the most legume accessions collected (70), mainly from wilayat Rustaq, followed by Interior (66), Sharqiya (63) Dhahira and Buraimi (46), Dhofar governate (23) and North Batinah (15). In alfalfa (Medicago sativa), 67 seed samples/accessions were collected from 62 sites, with the most (25) from Sharqiya, 20 from Interior, 8 each from North Batinah and Dhahira and Buraimi, 6 from South Batinah and none from Dhofar. In fenugreek (Trigonella foenum-graecum), 49 seed samples/accessions were collected from 43 sites, with the most from Batinah South (14) represented mostly by Rustaq, followed by Interior (13), Sharqiya (12) and Dhahira and Buraimi (10). The seed accessions were diverse with respect to the seed characters studied i.e., seed length (cm) and width (cm), 100-seed weight (g) and seed color. The diverse nature of the legume seed accessions and their genetic erosion are discussed. © 2014 Friends Science Publishers.
Schutze N.,TU Dresden |
Kloss S.,TU Dresden |
Lennartz F.,TU Dresden |
Bakri A.A.,Directorate General of Agriculture and Livestock Research |
Schmitz G.H.,TU Dresden
Environmental Earth Sciences | Year: 2012
In this contribution, we introduce a stochastic framework for decision support for optimal planning and operation of water supply in irrigation. This consists of (1) a weather generator for simulating regional impacts of climate change on the basis of IPCC scenarios, (2) a tailor-made evolutionary optimization algorithm for optimal irrigation scheduling with limited water supply, (3) a mechanistic model for simulating water transport and crop growth in a sound manner, and (4) a kernel density estimator for estimating stochastic productivity, profit, and demand functions by a nonparametric method. As a result of several simulation/optimization runs within the framework, we present stochastic crop-water production functions (SCWPF) for different crops which can be used as a basic tool for assessing the impact of climate variability on the risk for the potential yield for specific crops and specific agricultural areas. A case study for an agricultural area in the Al Batinah region of the Sultanate of Oman is used to illustrate these methodologies. In addition, microeconomic impacts of climate change and the vulnerability of the agro-ecological system are discussed. © 2011 Springer-Verlag.
Al-Raisy F.S.,Directorate General of Agriculture and Livestock Research |
Al-Said F.A.,Sultan Qaboos University |
Al-Rawahi M.S.,Directorate General of Agriculture and Livestock Research |
Khan I.A.,University of Agriculture at Faisalabad |
And 2 more authors.
European Journal of Scientific Research | Year: 2010
Studies were carried out to observe strawberry response to four growing substrates under a vertical hydroponics system under non-cooled shade house conditions during winter season at Rumais, Oman. The productivity response of strawberry was assessed in respect to biomass indices, yield, quality and ionic concentration attributes. The results indicated that column types had a significant effect on most of the characters studied; growing substrate also showed significant effects on some characters while there was a significant interaction with respect to fresh shoot weight and fruit juice pH. Among the column types, columns with 6-pots performed significantly better than others in terms of biomass yield and fruit quality attributes. Among the growth media, a mixture of perlite and peat moss irrespective of their ratios showed significant superiority compared to the mixture of perlite and local plant fibre. It can be concluded that vertical hydroponics systems could be used for cultivation of strawberry in 6-pot columns with peat moss or local peat. However, the use of local plant fibre (shredded date leaf bases) is recommended because of cost and availability. The results demonstrated that strawberries could be produced under non-cooled shade-house conditions in Oman with fruit yields of 8-10 kg/m 2 comparable to yields obtained else where. © EuroJournals Publishing, Inc. 2010.