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Field bindweed (Convolvulus arvensis L.) is a troublesome weed of rainfed areas. Seed bank density, weed population dynamics and crop productivity were studied in wheat crop under different tillage treatments in a field experiment carried out during summer and winter seasons of 2012-2013 and 2013-2014. Different combinations of tillage, integrated with glyphosate herbicide were used in the fallow period (summer season). Results showed that tillage systems along with glyphosate in summer season controlled the establishment of seed bank density as observed in conventional tillage treatment. There was a positive and very week correlation between tillage intensity and seed bank density of C. arvensis L. Similarly the weed population dynamics with reference to importance value index of weed was minimum in 1 Disc harrowing + 4 cultivations that was not significantly different from no-till + glyphosate. Tillage intensity integrated with glyphosate showed negligible but negative correlation with the weed population dynamics. In crux, no tillage integrated with glyphosate is recommended for economical reduction of seed bank density and weed population of field bindweed in rainfed wheat areas. [ABSTRACT FROM AUTHOR]

Leaf and internode explants from in vitro grown seedlings of Citrullus colocynthis (L.) Schard. were used to establish callus cultures in MS media supplemented with different concentrations (ranging from 1 to 3 mg/L) and combinations of plant growth regulators like BAP with NAA, and Kin with 2, 4-D. BAP 3 mg/L and NAA 2 mg/L supported green to yellowish green embryogenic callus from internode explant with callus index of 300 and callus initiation commenced in 3 days. Leaf explant produced green callus under influence of 2, 4-D 2 mg/L and Kin 1 mg/L with callus index of 200 and callus initiation duration was 15 d. Leaf and internode tissues from in vitro grown seedlings and leaf and internode calli were analyzed for secondary metabolites through GC-MS. Nineteen compounds were detected from leaf and internode tissues. From the comparative analysis of secondary metabolites it can be concluded that regardless of a few different compounds, most of the secondary metabolites from seedlings were present in their respective calluses. [ABSTRACT FROM AUTHOR]

Tomato leaf curl virus (TLCV) is an emerging problem in tomato growing areas of Pakistan. Relationship of TLCV disease and environmental conditions were studied on five tomato cultivars. Temperature (maximum and minimum) and relative humidity significantly contributed in the development of TLCV disease during two years (2012 and 2013). The TLCV disease incidence increased with rise in maximum and minimum temperature and decreased with the increase in relative humidity. The contribution of maximum temperature was explained by linear regression which showed 83 to 91% variability in the disease incidence and minimum temperature explained 75 to 85% variability. Relative humidity exerted 78 to 85% contribution in the disease development. The linear regression could not explain the contribution of rainfall and wind speed in disease development. The characterization of favorable environmental conditions for TLCV disease development would contribute towards accurate prediction and timely management of the disease. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Barani Agriculture Research Institute Chakwal Punjab, Pakistan to assess the seed yield, nitrogen fixation and nutrient uptake by chickpea (Cicer arietinum L.) in response to application of different levels of phosphorus (P) and sulfur (S). The treatments comprised three levels (0, 40 & 80 kg P2O5 ha-1) of P and three levels (0, 15 & 30 kg S ha-1) of S from two sulfur S sources (gypsum & ammonium sulfate) in different combinations. The trial was laid out according to randomized complete block design with split split plot arrangement. Application of P and S resulted in significant increase in seed yield by 21 and 12% over control, respectively. Effect of combined application of P and S was synergistic at nutrient application rate of P40S15, while antagonistic at P80S30. Sulfur application had significant effect on percent nitrogen derived from atmosphere (% Ndfa), while effect of P was non-significant. There was significant increase in protein content of chickpea seed due to application of S. Application of both P and S resulted in increase in nitrogen (N) fixation by 16%. Value cost ratio was less than 2 for higher level of P either sole or in combination with S. A fertilizer combination of P40S30 is more economical and cost effective for chickpea production under rainfed conditions. [ABSTRACT FROM AUTHOR]

Field experiments were conducted at two locations in northern rainfed Punjab, Pakistan to assess the seed yield of chickpea (Cicer arietinum L.) in response to application of different levels of sulfur and phosphorus. The treatments comprised three levels (0, 40 & 80 kg P2O5 ha-1) of phosphorus and three levels (0, 15 & 30 kg S ha-1) of sulfur from two sulfur sources (gypsum & ammonium sulfate) in different combinations. Phosphorus was applied in the form of triple super phosphate. Crop was harvested at maturity and data were recorded for seed yield. Application of phosphorus and sulfur resulted in significant increase in seed yield up to 34 and 17 % over control, respectively. Effect of combined application of phosphorus and sulfur was synergistic at nutrient application rate of 40 kg phosphorus and 15 kg sulfur ha-1, while antagonistic at 80 kg phosphorus and 30 kg sulfur ha-1. Value cost ratio was higher for combined application of phosphorus and sulfur as compared to their sole application. Therefore either 80 kg phosphorus along with 15 kg sulfur ha-1 or 40 kg phosphorus in combination with 30 kg sulfur ha-1 should be applied in order to maximize profit from chickpea crop under rainfed conditions. [ABSTRACT FROM AUTHOR]

Urdbean (Vigna mungo (L.) Hepper) is an important pulse crop grown worldwide. ULCV is an important disease of urdbean in Pakistan, because it causes huge losses in production of urdbean. The susceptible germplasm and favorable environmental conditions also contribute towards the wide spread outbreak of viral diseases. Forty urdbean lines were screened against ULCV under field conditions. Correlation studies between environmental factors (temperatures & relative humidity) and ULCV infection in selected lines revealed positive interaction for maximum and minimum temperatures but a negative one for relative humidity. The comparative efficacy of 2% concentration of different plant extracts (neem, akk, garlic) against ULCV was determined. Plants sprayed with neem extract have least whitefly population followed by garlic and results showed that minimum disease severity was observed on plants that were sprayed with neem followed by akk. The results are helpful in the understanding of epidemiological factors that play vital role in disease spread. Furthermore, the plant extracts can be used to manage the vector populations, which ultimately reduce the disease incidence. [ABSTRACT FROM AUTHOR]