Helicoverpa armigera (Hübner) is one of the most destructive pests of several field and vegetable crops, with indiscriminate use of insecticides contributing to multiple instances of resistance. In the present study we assessed whether H. armigera had developed resistance to Bt cotton and compared the results with several conventional insecticides. Furthermore, the genetics of resistance was also investigated to determine the inheritance to Cry1Ac resistance. To investigate the development of resistance to Bt cotton, and selected foliar insecticides, H. armigera populations were sampled in 2010 and 2011 in several cotton production regions in Pakistan. The resistance ratios (RR) for Cry1Ac, chlorpyrifos, profenofos, cypermethrin, spinosad, indoxacarb, abamectin and deltamethrin were 580-fold, 320-, 1110-, 1950-, 200-, 380, 690, and 40-fold, respectively, compared with the laboratory susceptible (Lab-PK) population. Selection of the field collected population with Cry1Ac in 2010 for five generations increased RR to 5440-fold. The selection also increased RR for deltamethrin, chlorpyrifos, profenofos, cypermethrin, spinosad, indoxacarb, abamectin to 125-folds, 650-, 2840-, 9830-, 370-, 3090-, 1330-fold. The estimated LC50s for reciprocal crosses were 105 µg/ml (Cry1Ac-SEL female × Lab-PK male) and 81 g µg/ml (Lab-PK female × Cry1Ac-SEL male) suggesting that the resistance to Cry1Ac was autosomal; the degree of dominance (DLC) was 0.60 and 0.57 respectively. Mixing of enzyme inhibitors significantly decreased resistance to Cry1Ac suggesting that the resistance to Cry1Ac and other insecticides tested in the present study was primarily metabolic. Resistance to Cry1Ac was probably due to a single but unstable factor suggesting that crop rotation with non-Bt cotton or other crops could reduce the selection pressure for H. armigera and improve the sustainability of Bt cotton.

This two-year study observed the influence of various barley-based cropping systems on soil physicochemical properties, allometric traits and biomass production of barley sown under different tillage systems. Barley was cultivated in different cropping systems (CS), i.e., fallow-barley (fallow-B), maize-barley (maize-B), cotton-barley (cotton-B), mungbean-barley (mungbean-B) and sorghum-barley (sorghum-B) under zero tillage (ZT), minimum tillage (MT), strip tillage (ST), conventional tillage (CT) and bed-sowing (BS). Interaction between different CS and tillage systems (TS) positively influenced soil bulk density (BD), total porosity, available phosphorus (P), ammonical and nitrate nitrogen (NH4-N and NO3-N), available potassium (K), allometric traits and biomass production of barley. The highest soil BD along with lower total porosity were noted in ZT leading to lesser leaf area index (LAI), leaf area duration (LAD), specific leaf area (SLA), crop growth rate (CGR) and net assimilation rate (NAR) of barley. Nonetheless, bed-sown barley produced the highest biomass due to better crop allometry and soil physical conditions. The highest postharvest soil available P, NH4-N, NO3-N, and K were recorded for zero-tilled barley, while BS followed by CT recorded the lowest nutrient contents. Barley in mungbean-B CS with BS produced the highest biomass, while the lowest biomass production was recorded for barely sown in fallow-B cropping system with ZT. In conclusion, barley sown after mungbean (mungbean-B cropping system) with BS seems a pragmatic choice for improving soil fertility and subsequently soil health.

Cadmium is acute toxicity inducing heavy metal that significantly decreases the yield of crops. Due to high water solubility, it reaches the plant tissue and disturbs the uptake of macronutrients. Low uptake of nutrients in the presence of cadmium is a well-documented fact due to its antagonistic relationship with those nutrients, i.e., potassium. Furthermore, cadmium stressed plant produced a higher amount of endogenous stress ethylene, which induced negative effects on yield. However, inoculation of 1-amino cyclopropane-1-carboxylate deaminase (ACCD), producing plant growth promoting rhizobacteria (PGPR), can catabolize this stress ethylene and immobilized heavy metals to mitigate cadmium adverse effects. We conducted a study to examine the influence of ACCD PGPR on nutrients uptake and yield of bitter gourd under cadmium toxicity. Cadmium tolerant PGPRs, i.e., Stenotrophomonas maltophilia and Agrobacterium fabrum were inoculated solely and in combination with recommended nitrogen, phosphorus, and potassium fertilizers (RNPKF) applied under different concentration of soil cadmium (2 and 5 mg kg−1 soil). Results showed that A. fabrum with RNPKF showed significant positive response towards an increase in the number of bitter gourds per plant (34% and 68%), fruit length (19% and 29%), bitter gourd yield (26.5% and 21.1%), N (48% and 56%), and K (72% and 55%) concentration from the control at different concentrations of soil cadmium (2 and 5 mg kg−1 soil), respectively. In conclusion, we suggest that A. fabrum with RNPKF can more efficaciously enhance N, K, and yield of bitter gourd under cadmium toxicity.

The present study is an effort to document bio-geographical distribution for Zygoptera of Pakistan. Damselflies were collected throughout the country and territory of Azad Jammu and Kashmir during 2004–2009. A total of 2692 specimens were collected yielding 9 families, 21 genera, and 48 species and subspecies. Three of these species, Libellago lineata lineata (Burmeister), Elattoneura atkinsoni (Selys), and Elattoneura souteri (Fraser), are recorded for the first time from Pakistan. Distribution, habitats, previous records, and Zoogeographic affiliation for all collected taxa are discussed. Help was also taken from published literature on Zygoptera of Pakistan, and specimens housed at National Insect Museum were also studied. In total, 53 species are accounted for providing an updated record for all modern taxa of damselfly fauna of Pakistan.

Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1tiller), and highest plant height (85.8cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320m), straw yield (8.6Mgha), and grain yield (4.8Mgha) were achieved when seeds were inoculated with Bacillus sp. strain 6+Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6+Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity.