Search

Most of the diseases affecting plant nurseries are soil borne and to eradicate the pathogens from growing media different sterilization (chemical, solar and steam) techniques are used. Steam sterilization is more efficient and environmentally friendly technology. To test the effectiveness of steam sterilization in controlling growth of fungal pathogens, different fungal species were isolated from various potting media (soil, sand, silt, FYM and coconut coir) pre and post steam sterilization and the isolates were characterized. Pre-sterilization fungal isolation was performed using serial dilution method which revealed different fungal species i.e., Aspergillus flavus, A. niger, Fussarium solani, Penicillium spp, Rhizoctonia spp, Curvularia spp, and Pythium spp. After sterilization, one group of potting media was kept open and the other one was tightly packed and placed at ambient temperature. These open and covered media types were evaluated for fungal regrowth by isolation after 7 days, 15 days and 30 days intervals. Different fungal contaminants were found in the potting media that was kept opened after sterilization. However, interestingly no soil related fungal pathogens were observed in the packed potting media 30 days post sterilization. These findings extended the current knowledge of steam sterilization of potting media and suggest that steam sterilization can effectively eliminate the fungal pathogens from the media. Further, it could be effectively used to produce sanitated plant nurseries and minimize the spread of soil borne diseases. [ABSTRACT FROM AUTHOR]

The tulip is an important cut flower around the globe. The Tulip is not famous in Pakistan for sale and cultivation for commercial purposes as well. The evaluation of exotic varieties are very important for recommendation to local farmers for better yield. Four tulip varieties cv. Antarctica, Oxford, Ballerina and Apeldoorn were purchased for evaluation. The 100 bulbs of each variety were planted in the bed. The performance of the plants during 2017-18 were judged by observing the bulb germination percentage, leaf width (cm), leaf length (cm), scape length (cm), flower size (mm), primary color of the flower, secondary color of flower, no. of large, medium and small size of bulbs and number of bulbs harvested. The bulbs were harvested and stored at 5±2oC (In Refrigerator). The morphological attributes of plants were observed better in cv. Antarctica and Oxford. The research was repeated during the subsequent years. The variable response was observed in various varieties of tulip in Rawalpindi climate. The cv. Antarctica and Oxford were observed as best performer wise all the attributes. The same varieties are recommended to local farmers for cultivation as well. [ABSTRACT FROM AUTHOR]

Guava (Psidium guajava L.) fruit physical and chemical characterization was performed across six distinct summer and winter seasons (Year I-III) in two elite cultivars (Round and Pyriform) to assess genotypic and seasonal variations and their correlations with the key environmental components. A strong negative correlation was found between in temperature with ratio fruit length to fruit diameter (FL:FD), total sugars (%) and rain fall with fruit weight, seed cavity weight and total sugars (%). Relative humidity (%) and sunshine (hrs) were positively correlated to fruit weight and ratio TSS:TA suggesting existence of a higher genotype × environment interplay which regulated contrasting changes in fruit traits. Most of the physical and chemical traits were higher in cv. Pyriform compared with cv. Round. Fruit produced in winter seasons had markedly better physical and chemical attributes compared with that of summer seasons. However, acid contents were higher during summer seasons. Traits like reducing sugars and ratio flesh weight and seed cavity weight (FlW:SCW) remained stable across contrasting summer and winter seasons over the years in both cultivars. Assessment of guava fruit physicochemical traits across multiple seasons provided precise estimates of genetic, seasonal and annual variations which could be useful in selection of parental material for future guava breeding and biotechnology applications. [ABSTRACT FROM AUTHOR]

Rose is a highly economically important ornamental plant being globally used for aesthetic purposes since ancient times. In Pakistan, during last seventy years hundreds of Hybrid varieties were introduced and adopted for cut-flower production and landscape beauty. Several spontaneous mutants may also have originated during clonal propagation. In 2008, a comprehensive survey of Punjab areas was conducted and several hybrids were collected and planted in semi sub-tropical area (Rawalpindi/Islamabad). The varieties with stable phenotypic characters were further subjected to morphological analysis following UPOV-Rose descriptors during 2017 to 2019. Morphological diversity was analyzed using principal component analysis (PCA), cluster analysis and a large ratio of the characters was considered as dominant. The narrow range of variation was found within germplasm of Hybrid accessions and traits (11.43% and 10.14%) on factor plains (Factor 1 × Factor 2). The leading accessions 33, 34 and 6 were selected for their desirable plant attributes such as better flower size (cm), stem length (cm) and early flower production. Establishment of in vitro clonal propagation was required for efficient multiplication. The explants were surface sterilized by pre-soaking in Topsin-M fungicide and sequential use of HgCl2 and NaOCl. Phenolic exudation was controlled using 1% Citric acid solution. Among selected accessions, #33 performed better for efficient establishment of cultures and in vitro clonal multiplication. Hence, it may be used for further clonal propagation using tissue culture for commercial production. This is first report of the adoptability studies of different HT-Rose accessions in Pakistan and their capacity to be used in selection and breeding programs. [ABSTRACT FROM AUTHOR]

Guava cultivation is rapidly rising in the progressive farming community due to its early bearing habit, long harvesting span and meadow orchard culture. However, in the last 7-8 years, despite 25% increase in the area under cultivation, production has not increased accordingly and per hectare yield has decreased up to 13% mainly due to guava decline which is alarming situation. In this scenario, extensive surveys were conducted to estimate the damage caused by guava wilt disease which is badly affecting guava industry and farming community. Infected trees were found at a much higher proportion in cv. Pyriform (Surahi) in Lahore (52.92%) and Faisalabad (65.12%) regions compared with cv. Round (Gola). Most of the elite strains in both Pyriform and Round cultivars across different regions in central and southern Punjab were found infected with wilt disease. In Pyriform, strains viz. Large Surahi, Small Surahi and Sadabahar Surahi while in cv. Round, Large Gola and Sadabahar Gola strains were more susceptible to wilt compared with other strains. Cytological characterization of isolates recovered from infected roots collected during surveys showed frequent involvement of Fusarium species in guava decline. Further characterization and screening of elite guava strains for tolerance against wilt disease is in progress. Such studies will lead towards identification of guava strains tolerant to GWD for future breeding and biotechnology applications. [ABSTRACT FROM AUTHOR]