Muhammad Naeem

Study of correlation among yield related traits and path coefficient analysis in rice (Oryza sativa L.)

In order to determine the associations among yield components and their direct and indirect influence on grain yield of rice, an experiment was conducted. For this purpose, 30 genotypes collected from different sources were tested in a randomized complete block design. The phenotypic correlations among the yield traits and their path coefficient were estimated. Grain yield was significantly correlated with its component characters; number of productive tillers per plant, number of grains per panicle and flag leaf area. Path analysis revealed that days to maturity had the highest direct effect (0.751) on grain yield per plant. In addition, the yield components had positive direct effect on grain yield except the days to heading (-0.834). The order of yield components was the number of productive tillers per plant, flag leaf area and 1000 grain weight. The improvement in grain yield will be efficient if the selection is based on biological yield components, number of productive tillers per plant and flag leaf area. These traits may also be utilized in pure line selection. Keywords : Rice ( Oryza sativa ), path coefficient, phenotypic correlation, yield components

Low Pyrolysis Temperature Biochar Improves Growth and Nutrient Availability of Maize on Typic Calciargid

ABSTRACT This experiment was conducted to investigate the effects of biochars, produced from maize straw at different temperatures (300, 400, and 500 °C), on growth of maize. Maximum cation exchange capacity (CEC) (106 cmolc kg‒1) of biochar was observed at 400 °C. The pH, electrical conductivity (EC), and carbon content of biochars significantly increased with increasing temperature, and maximum pH (9.8), EC (3.0 dS m‒1), and carbon content (607 g kg‒1) were observed at 500 °C. Concentration of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) significantly increased with increasing temperature, while of nitrogen (N) decreased. Ammonium bicarbonate–diethylene triamine penta acetic acid (AB-DTPA)–extractable nutrients were decreased with increasing pyrolysis temperature. Shoot and root dry matter of maize increased significantly with application of biochar produced at 300 and 400 °C and decreased significantly at 500 °C. Maximum shoot and root dry matter of maize was obtained at biochar produced at 300 °C. Phosphorus and K concentration in shoots and roots increased with biochar, and it was significantly more with fertilizer application. In contrast to P, shoot and root K concentration increased significantly with increasing pyrolysis temperature. The results of this study indicated that application of biochar produced at low pyrolysis temperature may be a practical approach to improve crop growth.

Effect of Environmental Factors on Germination of Salsola foetida: Potential Species for Rehabilitation of Degraded Rangelands

ABSTRACT Information relating to germination and seedling emergence of a plant aids in determining the species potential distribution and also helps in designing appropriate plant management strategies within an agroecosystem. Salsola foetida Del. ex Spreng, a naturally occurring perennial shrub, is traditionally used as a medicinal plant and a promising camel fodder in the hypersaline, semiarid, and arid areas across the globe. A series of laboratory and greenhouse experiments were conducted to determine the effect of various environmental factors such as temperature, light, salinity, osmotic stress, pH, and seed burial depth on seed germination and seedling emergence of S. foetida. A decline in germination was observed with increases in temperature. The maximum germination of 95% was observed at 25/15°C followed by 83% at 30/20°C; however, minimum germination (35%) was observed at 40/30°C. Maximum seed germination (95%) was observed under 24-h darkness while a decrease in germination (72%) was recorded when seeds were kept in 24-h light. Under saline conditions, 67% of seeds germinated at 100 mM sodium chloride (NaCl) and germination decreased to 12% with an increase in salinity to 500 mM NaCl. The optimum pH for seed germination of S. foetida was 7 (97% germination), although 36% and 75% of seeds germinated at the pH levels of 5 and 10, respectively. About 5% of seeds germinated at an osmotic potential of — 0.8 MPa compared with 40% at — 0.2 MPa. However, seeds of S. foetida were found sensitive to increased burial depth. The maximum germination was observed at the soil surface, and emergence inhibited completely from the seeds buried at the 5-cm depth. The high germination ability of S. foetida over a wide range of environmental factors suggests that this species is likely to thrive easily under harsh arid conditions. Therefore, it is used as a potential candidate for the rehabilitation of rangelands and will be helpful in mitigating the adverse effect of climatic changes on humans and livestock in the degraded areas.

Irrigation with brackish water modifies the boron requirement of mungbean (Vigna radiata L.) on typic calciargid

The boron (B) sufficiency range for plant growth is narrow and its management is problematic under brackish irrigation water. This study was conducted to evaluate the B requirement of mungbean at different sodium adsorption ratios of irrigation waters (SARiw) [control, 8 and 16 (mmolc L−1)1/2]. The boron adsorption characteristics of a loamy soil were first determined in the laboratory by equilibrating 2.5 g soil with 0.01 M CaCl2 solution containing different B levels. Boron rates for a pot study were computed against different soil solution levels by fitting sorption data in a modified Freundlich model [x/m = K f (EBC)1/n ]. The maximum increase in shoot dry matter was 11.9% when B was applied at 1.29 mg kg−1 soil at control SARiw. Visual leaf B toxicity symptoms appeared at higher B rates and became severe at higher SARiw. By contrast to Ca, shoot concentrations of B and Na increased significantly with B application and SARiw. For optimum shoot growth, internal and external B requirements were 25 mg B kg−1 shoot dry matter and 0.39 mg B L−1 soil solution, respectively, at control SARiw. At higher SARiw, a lower concentration of B in plant shoots and soil solution had an inhibitory effect on plant growth.

Weed Dynamics in Wheat-Canola Intercropping Systems

Las malezas causan grandes perdidas debidas a competencia con los cultivos. El intercultivo de trigo (Triticum aestivum L.) con canola (Brassica napus L.) bajo diferentes arreglos espaciales se evaluo por sus efectos en malezas e interaccion entre los cultivos en el Area de Investigacion Agronomica, Universidad de Agricultura, Faisalabad, Paquistan, durante 2009-2010. Los tratamientos incluyeron trigo (siembra lineal), canola (siembra lineal), trigo (siembra al voleo), una hilera de trigo + una hilera de canola (separadas 30 cm), dos hileras de trigo + dos hileras de canola (separadas 45 cm), cuatro hileras de trigo + cuatro hileras de canola (separadas 75 cm) y cultivo mixto de trigo + canola (siembra al voleo). Los resultados revelaron que todos los tratamientos de intercultivo afectaron significativamente densidad y peso seco de la maleza sobre el cultivo de trigo solo. El cultivo mixto de trigo + canola redujo el peso seco de Phalaris minor Retz., Chenopodium album L., Rumex dentatus L., y Coronopus didymus L. en 94; 77,2; 77,4; y 92%, respectivamente, sobre el cultivo de trigo solo. Los otros tratamientos de intercultivo como una hilera de trigo + una hilera de canola, dos hileras de trigo + dos hileras de canola, y cuatro hileras de trigo + cuatro hileras de canola generalmente redujeron peso seco total de las malezas en 81, 74, y 76%, respectivamente. Cuatro hileras de trigo + cuatro hileras de canola dieron las relaciones equivalente tierra mas altas de 1,37 y beneficio neto de Rs 93 543 seguido por dos hileras de trigo + dos hileras de canola. Se sugirio que el sistema de intercultivo trigo-canola en condiciones agroecologicas de Faisalabad pudo aumentar la relacion equivalente tierra > 1 (sobre-produccion) al suprimir las malezas.

Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat

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 (2.1 tiller−1), and highest plant height (85.8 cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320 m−2), straw yield (8.6 Mg ha−1), and grain yield (4.8 Mg ha−1) 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.

High Sodium in Irrigation Water Caused B Toxicity at Low Soil Solution and Shoot B Concentration in Maize (Zea mays L.)

Sodium (Na) and calcium (Ca) in brackish water differentially affects boron (B) nutrition of plants grown on calcareous and salt-affected soils. A glasshouse experiment was conducted to evaluate the effect of brackish irrigation water with different sodium adsorption ratio (SARiw) [distilled-water control, 8, and 16 (mmolc L−1)1/2] on B nutrition of maize. Plants were grown for 40 days with 5 levels of B (0, 1.29, 2.30, 3.22, and 4.46 mg kg−1 soil). Boron application significantly improved plant growth at lower rates. High B rates and application of high SARiw decreased plant growth independently, and the reduction in growth was further aggravated due to combined effect of both B and high SARiw. Decreased growth was attributed mainly to increased shoot B and Na concentration, while decreased Ca concentration. These ionic changes also altered internal and external B requirements. Yield decrease was observed at lower B concentration in soil solution B and plants shoot grown with high SARiw than in plants grown with distilled water and low B application rates.