Syed Aftab Wajid

Impact of nursery seeding density, nitrogen, and seedling age on yield and yield attributes of fine rice

Producing vigorous seedlings and transplanting them at the appropriate age are the most important factors for obtaining high yield in rice (Oryza sativa L.) paddy production. The impact of seeding densities, N, and seedling age was evaluated in this experiment after transplanting 10, 20, 30 and 40-d old seedlings raised by using different seeding rates (high and low) and N conditions (with and without) in the 2008 and 2009 rice growing seasons. The study revealed that 10-d-old nursery seedlings, irrespective of seeding densities and fertilizer application, showed higher yields and yield attributes (productive tillers, plant height, 1000-grain weight, and straw yield), while at later stages significant interaction was observed with nursery management. Transplanting of 20-d older fertile seedlings grown with low seeding density at nursery-bed, resulted in a higher number of productive tillers m-2 (233.3, 227.3), straw yield (11.1, 10.7 t ha-1), and final yield (3.6, 3.4 t ha-1) in both years, 2008 and 2009, respectively. Yield and yield attributes were significantly reduced by transplanting older seedlings grown at high seeding density and without N application at nursery-bed. Minimum productive tillers (165.7, 133), straw yield (8.7, 8.1 t ha-1) and paddy yield (2.0, 1.8 t ha-1) were recorded with transplanting 40-d older seedlings grown at high seeding density and without N application. These findings support the use of young seedling in a system of rice intensification and illustrate that by making a minor additional investment to raise healthy and vigorous seedlings in nursery seed-bed, farmers can improve yields.

Forecasting wheat yield from weather data and MODIS NDVI using Random Forests for Punjab province, Pakistan

ABSTRACT Wheat is the staple food of Punjab province of Pakistan, which contributes more than 75% of the total national production. Accurate and timely forecasting of wheat yield is a cornerstone for monitoring food security and planning for agricultural markets, but the efficiency of the current system for near real-time forecasting should be improved. In this research paper, we developed a model to forecast wheat yield before harvest for each of eight individual districts and for Punjab province as a whole. The model uses weather and Moderate Resolution Imaging Spectroradiometer (MODIS)-derived normalized difference vegetation index (NDVI) data for 2001–2014 (14 years) to calculate Random Forest (RF) statistical models using 15 independent variables. Temperature, rainfall, sunshine hours, growing degree days, and MODIS-derived NDVI for each of the eight districts of Punjab province were used to forecast yield for the year 2014. The same independent variables were used to forecast wheat yield of the whole Punjab from 2001 to 2014 by excluding the respective year from training set. Sunshine hour data were not available for all districts and therefore we tested using temperature data and average latitude-based solar radiation as surrogates. The root mean square errors (RMSEs) of the forecast results of the whole of Punjab province were 147.7 kg ha−1 and 148.7 kg ha−1 with a mean error of less than 5% using average and generic RFs, respectively. Forecasts for individual districts showed R2 of 0.95 with RMSE of 175.6 kg ha−1 and 5.86% mean error.

Potential soil moisture deficit: an alternative approach for irrigation scheduling in wheat.

Wheat is a staple food of Pakistan and its productivity is linked with water supply. Potential soil moisture deficit (PSMD) is an approach to save water. PSMD technique was utilized to grow early and late sowing wheat (Triticum aestivum L.) for optimum yield. The experiment was conducted at the agronomic research area, University of Agriculture, Faisalabad during 2010‒2011 and 2011‒2012. The experimental design was randomized complete block design in a split plot arrangement with three replications. The main plot was sowing dates (15 November and 15 December) and the sub-plots were levels of irrigation based on PSMD (full irrigation, 45 mm, 60 mm and 75 mm). The row spacing as set 20 cm and the seed rate was 125 kg ha using cv. Sahar-2006. Fertilizer was applied at 120:90 kg ha of nitrogen and phosphorus, respectively. Data were recorded for yield and yield components at maturity. Irrigation at 45 mm PSMD for crop sown on November 15 produced maximum grain yield. During both years, maximum plant height, number of grains per spike, thousand grain weight, productive of tillers (m), grain yield and WUE were recorded with full irrigation and irrigation at 45 mm PSMD respectively. Results revealed that deficit irrigation at 45 mm PSMD was water saving as compared to farmer conventional practice of full irrigation.

Dry Matter Partitioning and Mineral Constitution Response of Sunflower (Helianthus annuus) to Integrated Nitrogen and Boron Nutrition in Calcareous Soils

Abundant plant growth and development prominently rely on adequate supply of macro and micro nutrients. Among various nutrients, nitrogen (N) and boron (B) holds great importance in sustaining and enhancing the productivity of sunflower. In calcareous soils of Pakistan, B deficiency is prevalent that affects the uptake of nutrients. The present field study aimed to assess the impact of B on biomass production and nutrient absorption in calcareous soils by considering different B doses (0‒6 kg ha -1 ) under variable N rates (50‒100% RN ‘recommended nitrogen’) for consecutive two years of 2011 and 2012. The growth traits as leaf area index, leaf area duration, crop growth rate, net assimilation rate and dry matter accumulation were significantly affected with B rate of 3.20‒3.50 kg ha -1 with 100% RN. In addition, B rate of 3.44 kg ha -1 with 100% RN produced maximum biological yield and harvest index in both years. Leaf and achene N contents were higher by 3.32 and 3.38 kg B ha -1 , respectively with 100% RN fertilization as compared to 75% RN and 50% RN. B fertilization at 3.50 kg ha -1 also had highest B contents in leaf and achenes under 100% RN. The lower B contents were found at reduced level of 50% RN in contrast to 100% RN. Chlorophyll pigments (chl a, b and total) were also affected positively with B rate of 3.46 kg ha -1 under highest level of N nutrition. However, higher biomass production and mineral uptake could be obtained at 3.0-3.50 kg ha -1 B rate with 100% RN compared to 75% RN and 50% RN nutrition.