Imtiaz Khan

A PCR-based method, with internal control, for the detection of Banana bunchy top virus in banana

Banana bunchy top disease is a major constraint to banana production in most regions where this crop is grown. The disease is caused by Banana bunchy top virus (BBTV), a multicomponent, single-stranded DNA virus of the family Nanoviridae. We have designed primers to a conserved region of the master replication-associated protein that are useful for the polymerase chain reaction (PCR)-mediated detection of BBTV. In addition, primers to banana genomic sequence are used as an internal control, overcoming the uncertainty (owing to false-negatives) inherent in PCR diagnostics. Together these primer sets are a valuable tool in the effort to control BBTV, particularly in screening micropropagated banana plantlets for the absence of virus before release to farmers.

Yield and yield attributes of tomato (Lycopersicon esculentum Mill) cultivars influenced by weed management techniques

The performance of tomato cultivars (Lycopersicon esculentum Mill) was evaluated using various weed management techniques at the New Research Farm of The University of Agriculture, Peshawar-Pakistan during rabi season 2013-14. The research was carried out in randomized complete block design with split plot arrangement, having three replications. Eight weed management techniques (Black plastic as mulch, Eucalyptus leaves as mulch, Newspaper as mulch, Cyperus rotundus (weed extract), Convolvulus arvensis (weed extract), Ammi visnaga (weed extract), Hand weeding and Control) and three cultivars of tomato (Roma, Money Maker and Rio Grand) were used. All the weed management practices were observed significantly different from one another. Management of weeds through hand weeding produced maximum plant height, branches plant, fruits plant, weight of fruit plant and yield as compared to control as well as the maximum weed density was recorded in control plots. Tomato cultivars were significantly different from one another for all the parameters studied. The cultivar Money Maker had the maximum plant height, branches plant, fruits plant, weight of fruit plant and yield as compared with other tomato cultivars. While maximum weed density was recorded in cultivar Roma but statistically at par with cultivar Rio Grand. It is concluded from this study that growing of cultivar Money Maker and hand weeding technique seems to be the best combination for tomato production in Peshawar for achieving highest yield of tomato crop.

Tolerance of Different Wild Oats Biotypes to Different Oat Killers and Their Impact on Wheat

The ecological starting point for crop health requires knowledge of what is in the soil (microbes, insects, weed seeds, etc.), methods to prevent herbicides resistance build up in the crop, and knowledge to maximize the plants ability to defend itself. The focus of most current crop production practices is weed control with little effort applied by herbicides. Cropping practices that degrade soil and limit genetic diversity contribute to increasing weed populations. A field experiment was initiated at Malkandher Research Farm, NWFP (North West Frontier Province) Agricultural University, Peshawar during Rabi 2005–2006 to figure out the tolerance of different wild oats (noxious weed) biotypes to herbicides. The experiment was laid out in randomized complete block design under a split-plot arrangement, with three replications. The experiment comprised of four wild oats biotypes assigned to the main plots, while 3 herbicides along with a weedy check (Sencor, Isoproturon, Affinity and Weedy check treatment) were kept in sub-plots. The Ghaznavi-98 variety of wheat in a sub-plot size of 5 × 1m2 was planted on November 13, 2005. The data were recorded on tillers plant−1, wheat spikes m−2, number of grains spike−1, 1,000 grain weight (g), biological yield (t ha−1), grain yield (t ha−1) and the protein content (%) in grain. The statistical analyses of data exhibited non-significant differences for tolerance of biotypes to herbicides in all the morphological and agronomic traits, while herbicides and their interaction with biotypes were significant for all the traits examined except wheat plant height. As a consequence of phytotoxic effect on weeds, the herbicides increased grain yield and yield components. The herbicide Affinity out yielded rest of the herbicides. In general, the highest grain yield was harvested in Affinity treated plots across all the wild oats biotypes. The interaction of biotypes with the herbicides exhibited a differential competitive ability or tolerance to different herbicides. It is thus recommended that judicious thinking is desired to control different biotypes infesting farmers’ fields because wild oat (Avena fatua L.) is one of the most troublesome weeds in the weed community. The Pakistani prairies are a semiarid region prone to soil erosion, and appears to be an appropriate site to adopt conservation tillage practices. Due to the environmental concerns and the development of herbicide resistance, it would be desirable to integrate all aspects of crop management systems, rather than solely rely on herbicides, to manage wild oat problems.