Modeling Sunflower Productivity and Profitability in Relation to Adequate and Limited Sulphur Availability under Semiarid Irrigated Conditions

Inadequate and/or imbalanced fertilization has been identified as one of the critical bottlenecks holding oilseeds production and productivity. Sustainable production requires efficient use of inputs maintaining optimum yield and high quality product. The present study aims at defining the quantitative relationship between the fertilizer S applied and the sunflower yield obtained using a polynomial function. The analysis was done to allocate the S fertilizer for maximization of net profit over fertilizer cost depending on the availability of the fertilizer. The results indicated that the cost effective economically optimum dose of sulphur for sunflower cultivation was found to be 36.70 kg S/ha under its full availability. The expected sunflower yield at this dose was worked out to be 2.619 t/ha. However, it is advisable to uniformly distribute the fertilizer to all over the cultivable area under its limited availability for exploiting the desired yield potential and maximum net monetary returns

Genotypic variation in some quality traits of malt barley ( Hordeum vulgare L.) caused by time of nitrogen application and kernel position within spike

The effect of time of nitrogen application and position of kernels in spike on kernel weight, protein content, β-amylase activity and β-glucan content were examined in two cultivars of barley. Cultivar 92-11 produced significantly bold kernels and lower β-glucan content with slightly lower protein content and higher β-amylase activity than cultivar Xiumei 3. Time of nitrogen application significantly influenced the quality parameters studied. Application of 110 kg N/ha at tillering produced significantly higher kernel weight and significantly lower protein content as well as β-glucan content as compared to its application made at boot stage. β-Amylase activity was also lowest in case of nitrogen applied at tillering stage. There were significant differences between two cultivars for quality parameters when kernels were selected from different spike positions or where specific plant part was removed at heading. The highest 1000-kernel weight was recorded in 92-11 (52.5%) with removal of side tillers and in Xiumei 3 (42.2%) from the middle portion of spike; whereas for protein content, opposite trend was obtained. β-Amylase activity in both cultivars was the highest when middle portion of spike was removed. The lowest β-glucan contents in 92-11 and Xiumei 3 were registered with removal of flag leaf and in Xiumei 3 with the removal of middle portion of spike

Effect of time of nitrogen application on the growth and yield of two barley (Hordeum vulgare L.) cultivars

A field experiment was conducted in China during winter season of 2001–2002 to study the response of time of nitrogen application on two cultivars (Xiumei 3 and 92-11) of barley. Apart from basal dose of 40 kg N/ha, 110 kg N/ha was applied at tillering (T 1 ) or in two equal splits at tillering and boot stages (T 2 ) or at boot stage (T 3 ). Cultivar 92-11 attained significantly lower plant height at boot stage and number of spikes/plant but took significantly more number of days to heading, registered significantly more chlorophyll content in leaves at different growth stages, produced significantly more number of grains/spike, grain weight/spike, single grain weight, N concentration at boot stage and consequently produced significantly higher grain yield (3764 kg/ha) than cultivar Xiumei 3 (3201 kg/ha). Application of nitrogen at boot stage significantly reduced the plant height at both stages, dry matter accumulation, days taken to heading, leaf chlorophyll content at boot stage, grains per spike, grain weight per spike and individual grain weight but recorded significantly higher chlorophyll content in leaves at heading stage and higher N content as compared to its application at tillering. Split application of nitrogen at tillering and boot stages also recorded significantly better growth and yield attributes, N concentration and grain yield than its application at boot stage alone but was at par with nitrogen applied at tillering except grain weight per spike. Consequently application of nitrogen at tillering or its split application at tillering and boot stages produced statistically similar (4052 and 3816 kg/ha, respectively) but significantly higher grain yield than its application at boot stage (2500 kg/ha)

Modeling sunflower productivity and profitability in relation to adequate and limited sulfur availability under semiarid irrigated conditions.

Inadequate and/or imbalanced fertilization has been identified as one of the critical bottlenecks holding oilseeds production and productivity. Sustainable production requires efficient use of inputs maintaining optimum yield and high quality product. The present study aims at defining the quantitative relationship between the fertilizer S applied and the sunflower yield obtained using a polynomial function. The analysis was done to allocate the S fertilizer for maximization of net profit over fertilizer cost depending on the availability of the fertilizer. The results indicated that the cost effective economically optimum dose of sulphur for sunflower cultivation was found to be 36.70 kg S/ha under its full availability. The expected sunflower yield at this dose was worked out to be 2.619 t/ha. However, it is advisable to uniformly distribute the fertilizer to all over the cultivable area under its limited availability for exploiting the desired yield potential and maximum net monetary returns

Allelopathy for weed control in agricultural systems

Weeds are a hidden foe for crop plants, interfering with their functions and suppressing their growth and development. Yield losses of ~34% are caused by weeds among the major crops, which are grown worldwide. These yield losses are higher than the losses caused by other pests in the crops. Sustainable weed management is needed in the wake of a huge decline in crop outputs due to weed pressure. A diversity in weed management tools ensures sustainable weed control and reduces chances of herbicide resistance development in weeds. Allelopathy as a tool, can be importantly used to combat the challenges of environmental pollution and herbicide resistance development. This review article provides a recent update regarding the practical application of allelopathy for weed control in agricultural systems. Several studies elaborate on the significance of allelopathy for weed management. Rye, sorghum, rice, sunflower, rape seed, and wheat have been documented as important allelopathic crops. These crops express their allelopathic potential by releasing allelochemicals which not only suppress weeds, but also promote underground microbial activities. Crop cultivars with allelopathic potentials can be grown to suppress weeds under field conditions. Further, several types of allelopathic plants can be intercropped with other crops to smother weeds. The use of allelopathic cover crops and mulches can reduce weed pressure in field crops. Rotating a routine crop with an allelopathic crop for one season is another method of allelopathic weed control. Importantly, plant breeding can be explored to improve the allelopathic potential of crop cultivars. In conclusion, allelopathy can be utilized for suppressing weeds in field crops. Allelopathy has a pertinent significance for ecological, sustainable, and integrated weed management systems

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An experiment was conducted during 2003–05 to assess the production potential, biological and economic feasibility of intercropping maize with blackgram in different row proportions under rainfed conditions. Intercropping blackgram with maize, irrespective of row arrangements was found to be beneficial in increasing the system’s total productivity and yield advantage to the tune of 9.3–48.0% under different intercropping systems compared to monocultures of both maize and blackgram. Among the intercropping systems, maize (50 cm) with blackgram in 1 : 1 row proportion was proved to be the most efficient, productive and remunerative as it gave the highest mean maize equivalent yield (3 430 kg/ha) and also accounted for highest values for land equivalent ratio (1.34), relative crowding co-efficient (4.49), area-time equivalent ratio (1.23), income equivalent ratio (1.52), sustainability yield index (0.90), production efficiency (36.9 kg/ha/day), net returns (8.54×103 Rs/ha) and B: C ratio (1.78) compared to other intercropping systems, thus, can be suggested as a biological and economically sustainable intercropping system for higher productivity and profitability under rainfed conditions. Magnitude of reduction in yield of the base crop due to intercropping of blackgram was the highest (41.8– 46.2%) when maize was widely planted either at 75 or 90 cm in 1: 2 row ratios as against the 21.8–27.1% for maize planted at 50/60 cm in 1: 1 row proportion. Paired row planting showed yield reduction to the extent of 29.0–29.8%.PAU Ludhian

Role of competition in managing weeds: an introduction to the special issue

Weeds represent a significant challenge to successful crop production. Highly effective and sustainable weed control is required in order to meet global food demand. In this context, excessive use of herbicides has resulted in serious environmental and ecological issues. There are several weed control options which neither harm the environment nor require a significant increase in cost of production. Improving crop competition is particularly important and attractive among such options, which can be achieved by using crop cultivars possessing a competitive advantage over weeds, and manipulating the seed rate and direction of crop rows. Crop cultivars possessing traits such as fast germination, quick growth, high biomass, and large leaf area have a competitive advantage over weeds. Sowing such cultivars has been shown to suppress weeds in various crops. The use of high seed rates and narrow row spacing, if properly manipulated, can cause a significant decrease in weed proliferation in the crops. These techniques (cultivar, seed rate, row spacing, and row direction) are under-exploited as weed control methods, and offer considerable potential for achieving environmentally benign weed management. This special issue on “Eco-friendly Weed Management” will address the role of crop competition in managing weeds in different crops as well as in different countries