No abstract

Soil aggregate stability is an important indicator for controlling soil losses and can improve soil quality, particularly in an area such as the Loess Plateau. The objective of this study was to estimate the differences in soil aggregates across six different land-use systems (grassland, apple orchard, abandoned apple orchard, cropland maize, cropland wheat, and shrub-grassland). For this purpose, dry and wet sieving techniques were employed to assess aggregate content and aggregate stability. Higher percentages of water stable aggregates were observed in the abandoned apple orchard and shrub-grassland at 63% and 61%, respectively. The maximum dry aggregate stability (%) was recorded at 78% and 77% in both wheat cropland and common apple orchard, and the abandoned apple orchard was only 74%. Both mean weight diameters and geometric mean diameters of aggregate were recorded as higher in grassland, shrub-grassland, and the abandoned apple orchard, than the other land uses. The formation of soil aggregates and their stability were positively correlated with soil organic carbon content and root biomass of different plant communities. Higher amounts of soil organic carbon content were noted in the abandoned apple orchard, common apple orchard, and natural grassland at the 0-20 cm soil layer. The results of the correlation coefficient showed a positive significant correlation between the mean weight diameter, geometric diameter, root biomass, and soil organic carbon content. Conclusively, the type of land use affected the soil aggregation and distribution of size fractions; the small fractions of the aggregates formed large fractions by combining with fresh organic matter, and increased soil organic carbon concentrations were closely linked with the formation of macro-aggregates. Thus, converting slope farmland to forestland and grassland could improve water-stable aggregate and reduce soil disturbances in areas (like the Loess Plateau) with the highest erosion risk.

This study was conducted to investigate the factors affecting the adoption of organic farming in Peshawar-Pakistan. A total of 100 respondents were randomly selected from the four different cultivated areas of Peshawar, namely Palosi, Regi, Ternab and Pushtakhara. Binary logistic regression was used in this study to categorize the organic farming into adoption and non-adoption. The purpose of this model was to check the event probability for a categorical response variable with two outcomes. The results of the binary logistic show that factors affecting adoption of organic farming have a significant effect on the farmer productivity. Moreover, cost, productivity, profitability, compatibility and efficiency have a positive and significant effect. Thus, it is obvious that adopting organic farming not only to increase the farmer income but also to protect environmental pollution by avoiding the toxic chemical and fertilizer. Finally, we suggest that government agencies, extension and research institution should play a vital role to strengthen the awareness and advantages of organic farming.

In order to study the effect of salts stress on the growth and yield of wheat (cv. Inqalab), a pot experiment was conducted in the wire-house of the Department of Soil Science, Sindh Agriculture University Tando Jam. The soil was artificially salinized to a range of salinity levels i.e. EC 2.16, 4.0, 6.0, 8.0 and 10.0 dS•m −1 with different salts (MgCl 2 + CaCl 2 + Na 2 SO 4). The salinized soil used for the experiment was sandy clay in texture, alkaline in reaction (pH > 7.0) and moderate in organic matter (0.95%) content. The results showed that with increasing salinity there was an increase in the ECe, Na + , Ca 2+ , Mg 2+ and Cl − and decrease in the K + , SAR and ESP values of the soil Increasing salinity, progressively decreased plant height, spike length, number of spikelets spike −1 1000 grain weight and yield (straw and grain). Adverse effects of salts on plants were associated with the accumulation of less K + and more Na + and Cl − in their flag leaf sap, grains and straw. This resulted in lower K + :5Na + ratio in flag leaf sap, grains and straw of wheat plants. These results indicated that the effects of salts stress were greater at 10 than at 8, 6 and 4 EC dS•m −1 .

Cotton is one of the most important fibre crops playing a key role in economic and social affairs of the world. Water is a critical factor which influences on growth and yield of the cotton crop. Scarcity of water has put tremendous pressure on scientists to introduce drought tolerant cotton varieties. This study was aimed to determine water stress effects on the growth and yield of cotton. The present study was carried out to examine the effect of number of irrigations on the growth and yield of cotton during 2014. The field trial was conducted at the Experimental Fields of Agronomy Section, Agriculture Research Institute, Tandojam, Pakistan. A three replicated Randomized Complete Block Design (RCBD) was employed to layout the experiment having plot size of 2.5 m × 5 m (12.5 m 2). Four cotton varieties i.e. NIAB-78, Shahbaz-95, Sindh-1 and TH-224/87 were chosen for this study based on their frequent farmer usage. All the agronomic practices were performed according to standard procedures. Results showed that all the growth and yield components of cotton were significantly (P < 0.01) affected by varieties and irrigation frequencies with exception of monopodial branches and staple length, which were not significantly (P > 0.05) affected by irrigation frequencies. The cotton crop irrigated six times at 21 days interval showed better results with 138.16 cm plant height, 1.45 monopodial branches per plant, 21.83 sympodial * Corresponding author. A. Sahito et al. 1028 branches per plant, 44.58 bolls per plant, 33.86% G.O.T., and 26.97 mm staple length, 149.84 g seed cotton yield per plant and 2271.16 kg•ha −1 seed cotton yield. This study concluded that variety NIAB-78 showed superiority over Shahbaz-95, Sindh-1 and TH-224/87 in almost all the characters of economic importance, and the cotton crop received 6 irrigations at 21 days interval resulted in significantly economical overall performance as compared with 5 irrigations or 4 irrigations with higher seed cotton yield.

The present research work was carried out at Southern Wheat Research Station, Tandojam during the growing season 2013-14 in order to work out correlation and regression analysis for yield traits in wheat genotypes. The experiment was laid out in a Randomized Complete Block Design with three replications. Eight bread wheat genotypes such as Mehran, Sarsabz, TJ-83, SKD-1, Inqlab, A. Sattar, Sehar and Sassui were used to examine correlation and regression. Seven traits, viz.; plant height, tillers plant −1 , spike length, spikelet's spike −1 , grains spike −1 , seed index and grain yield plant −1 were studied. The analysis of variance revealed significant differences among the genotypes for plant height, tillers plant −1 , spike length, spikelet's spike −1 , grains spike −1 , seed index and grain yield plant −1. Based on mean performance, variety Sarsabz gave maximum plant height (95.46), produced maximum tillers plant −1 (4.40), gave more grain spike −1 (63.13), TJ-83 gave highest seed index (47.260), and was next ranker in spike length −1 (12.07), spikelet's spike −1 (19.13), grains spike −1 (59.86), and grain yield plant −1 (9.86) among the genotypes. The phenotypic correlations revealed that tillers plant −1 and grains spike −1 were highly positively associated; hence these yield components can be used as reliable selection criteria to improve grain yield in wheat. Thus estimation of correlation and regression analysis among yield and yield components may provide effective selection criteria to improve wheat grain yield. The results from correlation and regression of plant height indicated significantly positive association with spikelet's spike −1 , tillers plant −1 and grains spike −1 which revealed that increase in plant height will cause corresponding increase in associated traits.

The heterosis, heterobeltiosis, general combining ability (GCA) and specific combining ability (SCA) were examined during Rabi (crop season) of 2013-2014 in hexaploid wheat genotypes. The experiment for this study was conducted at the Botanical Garden, Department of Plant Breeding & Genetics, Sindh Agriculture University Tandojam, Pakistan. The breeding material was comprised of four parents (Imdad, TD-1, SKD-1, and Moomal). These parents were crossed in half partial mating fashion; thus, six possible cross combinations (F1s) were obtained (Imdad × TD-1, Imdad × SKD-1, Imdad × Moomal, TD-1 × SKD-1, TD-1 × Moomal, and SKD-1 × Moomal). A three-replicated RCB Design was used. The mean squares corresponding to different traits of various hexaploid wheat genotypes indicated significant (P < 0.01) GCA (parents) and SCA (F 1 hybrids) effects for the characters (plant height, tillers plant −1 , spike length, spikelets spike −1 , seeds spike −1 , seed index, and grain yield plant −1). The mean performance of F 1 hybrids differed significantly (P < 0.01) for all the traits studied. Among the parents, Imdad and TD-1 proved to be better general combiners for almost all the studied traits. In regards to SCA effects, the F 1 hybrids Imdad × TD-1 and Imdad × SKD-1 expressed higher SCA and heterotic effects for most of the studied traits.

An experiment was conducted to evaluate the productivity of wheat under different levels of phosphorus and method of application at Department of Agronomy, Sindh Agriculture University, Tandojam. Experiment was laid out in a RCBD (factorial) with three replications. The treatments were four phosphorus levels (P1 = 0 Kg•ha −1 + Recommended Nitrogen, P2 = 30 Kg•ha −1 + Recommended Nitrogen, P3 = 60 Kg•ha −1 + Recommended Nitrogen and P4 = 90 Kg•ha −1 + Recommended Nitrogen) and two placement methods (A1 = Drilling method and A2 = Broadcast method). The statistical analysis of phosphorus levels and placement exhibited significant differences to the maturity days, plant height, tiller production, spike length, grains per spike, seed index, harvest index and grain yield ha −1. However, the interactions of P levels and placement in all crop characters were non-significant except the grain yield/ha −1. The results revealed that application of 90 kg P ha-1 prolonged 143 days for maturity, taller plants (100.16 cm), more tiller plant −1 (13.50), lengthy spikes (12.83 cm), more grains spike −1 (51.33), heavier seed index (48.16 g), better harvest index (50.82%) and satisfactory grain yield (4240.50 Kg•ha −1). The unit increase in grain yield was positively correlated with the increased values of observed crop parameters by extending the values of maturity r = 0.85, plant height r = 0.94, tillers plant r = 0.96, spike length r = 0.95, grains spik −1 r = 0.97, seed index r = 0.95 and harvest index r = 0.97. It was concluded that 90 kg P ha −1 was superior level of phosphorus if, applied with seed drilling for obtaining satisfactory grain yield of wheat crop. S. Noonari et al.