Chlorophyll meter as a tool for forecasting wheat nitrogen requirements after application of herbicides

Because limited information is available about the validated use of a chlorophyll meter for predicting nitrogen requirements for optimum growth and yield of wheat after application of herbicides, field experiments were carried out in the winter seasons of 2011/2012 and 2012/2013 under different weed and N fertilization treatments. Five weeded treatments, application of herbicides 25 days after sowing (DAS), hand pulling once at 55 DAS and a weedy check were combined with four N application rates. Weeds were completely absent in the non-fertilized plots, either with metribuzin or hand pulling as well as in isoproturon-treated plots fertilized with 190 or 285 kg N ha^?1. The grain yield was similar in the treatments of isoproturon × 190 kg N ha^?1, isoproturon + diflufenican × conditional N treatment (113.9) or 190 kg N ha^?1, hand pulling × conditional N treatment (104.8) or 285 kg N ha^?1 and metribuzin × 190 kg N ha^?1. Under weeded practices, conditional N treatment recorded the maximum nitrogen use efficiency and almost equaled the grain protein content of the 190 kg N ha^?1 application rate. N application based on SPAD readings saved about 40.0% and 44.8% N with isoproturon + diflufenican or hand pulling, respectively, compared to the recommended rate (190 kg N ha^?1) without noticeable yield loss.     

Potentiality of Soil Mulch and Sorghum Extract to Reduce the Biotic Stress of Weeds with Enhancing Yield and Nutrient Uptake of Maize Crop

Two field trials were conducted in 2018 and 2019 to develop practical and economically efficient weed control programs in corn. The experiment included six treatments (cowpea, rice straw, sorghum extract, hoeing, foramsulfuron herbicide and weedy check). The treatments were arranged in randomized complete block design with four replicates. Findings showed that reduction in total weed number was evident with application of hoeing, cowpea and rice straw in 2018 and 2019 seasons, in addition to foramsulfuron herbicide and sorghum extract in 2019. Cowpea, hoeing, foramsulfuron herbicide and rice straw recorded higher reduction in dry biomass of grassy weeds in both seasons. Reductions in N, P and K uptake by weeds because of rice straw and cowpea treatments were similar to hoeing treatment in both seasons. The increases in ear grain weight and grain yield ha^?1 due to cowpea and hoeing treatments were similar to rice straw one. In 2019 season, cowpea treatment was the superior practice for improving N, P and K uptake of maize, significantly leveling hoeing for K uptake. The values of gross returns and benefit/cost ratio of cowpea and sorghum extract, respectively, were higher than rice straw application. In conclusion, cowpea as a live mulch achieved acceptable weed control in maize by reducing weeds growth and lowering their ability to deplete the soil nutrients. Also, cowpea treatment improves growth and yield of maize with better utilization of nutrients. Thus, cowpea could be exploited as an eco-friendly method of weed management programs in maize cultivation.

     

Cultivar selection as a tool for managing soil phosphorus and faba bean yield ‎sustainability

ABSTRACT

A sustainable agricultural tactics for countering a possible phosphate shrinking should comprise the releasing of legacy soil phosphorus (P), in parallel to lowering P fertilizer load, and increasing the use of recycled P sources with economic crop yield in mind. Therefore, a field trail was conducted to estimate the possibility of choosing the appropriate cultivar as a tool to raise the use efficiency of reserved soil P. Herein, three faba bean cultivars (Sakha-3, Nubaria-1 and Giza-843) were evaluated under five applications of P fertilizer (rock phosphate, super phosphate, Bacillus megaterium, rock phosphate+B. megaterium, and super phosphate+B. megaterium). Findings showed that the lowest value of estimated available P in soil after harvest was obtained from plots sown by Sakha-3 plants and fertilized with super phosphate+B. megaterium. Plots sown with Nubaria-1 and fertilized by rock phosphate+B. megaterium or B. megaterium (for weight of 100 seeds and seed yield) in addition to super phosphate+B. megaterium (for seed yield) produced the maximum increases. The highest P recovery efficiency was achieved with Nubaria-1 inoculated by B. megaterium alone. In conclusion, super phosphate+B. megaterium × Nubaria-1 achieve maximum crop returns and secure high short-term recovery of applied P.     

Exploiting Eichhornia crassipes Shoots Extract as a Natural Source of Nutrients for Producing Healthy Tomato Plants

Seeking for safe and cheap alternatives to provide the nutrient requirements of crops remains the most significant alternative for obtaining healthy and economical products. Thus, the present study aimed to assess the efficiency of aqueous water hyacinth shoot extract as a source of nutrients to feed tomato plants. Therefore, the effects of three fertilization treatments (without foliar spraying, commercial synthetic solution and natural solution of water hyacinth shoot extract) on the nutritional status and biomass yield of tomato were investigated. The experiment was designed in a randomized complete block design with three replicates. At different growth stages, several macro- and micronutrients, in addition to the final yield at harvest, were estimated. The results showed that at all growth stages of tomato (vegetative, flowering, fruiting and maturity), the natural solution of water hyacinth caused the maximum increases in phosphorus, iron, zinc, manganese, and selenium. However, the differences between the natural solution of water hyacinth and synthetic solution in nitrogen and potassium at the vegetative stage, phosphorus at the flowering and the fruiting stages, and manganese and selenium at the maturity stage were not significant. The increases in fresh and dry weights and fruit yield of tomato plants owing to the natural solution of water hyacinth application were 37.5, 56.8 and 72.2%, respectively, over the control. Natural organic solution of water hyacinth application increased the net return of tomato cultivation by approximately 1.84 and 1.63 times compared with the conventional practice (control) and synthetic chemical solution, respectively. It could be concluded that exploiting the natural organic solution of water hyacinth achieves several profits in agriculture via fertilization programs by enhancing the income of tomato farmers. Accordingly, it is recommended to benefit from the wastes of water hyacinth plants that are annually removed from the Nile River and other waterways.

     

Sunflower Response to Application of L-Ascorbate Under Thermal Stress Associated with Different Sowing Dates

Unlike edaphic factors, it is difficult to control climatic conditions and their changes that affect plant growth and development. To deal with such posture, farmers have to cultivate their crops at the right time. From this point, over two–year of 2014 and 2015, a field experiment was performed at El-Nubaria region, El-Behaira Governorate, Egypt, to assess the response of sunflower to different combinations between sowing dates (early, mid and delayed) and ascorbic acid treatments (with ascorbic acid and without ascorbic acid). Ascorbic acid was sprayed at 30, 40 and 50 days after sowing. The results showed that sowing sunflower in mid sowing (May 21) achieved the highest values of cumulative heat units utilization efficiency as well as all growth and yield traits, while the lowest values were recorded under the delayed sowing date (June 21). Application of ascorbic acid was effective for promoting growth and yield traits under all studied sowing dates. Ascorbic acid achieved 11.6, 10.1, 10.7 and 12.9% increases under early sowing, and 9.5, 6.6, 8.6 and 10.3% increases under delayed sowing in head diameter, seed weight plant^?1, seed yield and oil yield, respectively. Comparing to mid sowing?×?without ascorbic acid, application of ascorbic acid alleviated seed yield losses associated early sowing from 15.7–6.6% and from 23.0–16.4% with delayed one. In conclusion, for remediating the thermal stressful impacts of early or late sowing of sunflower, farmers are advised to treat crop plants with ascorbic acid to avoid yield losses.

     

Nitrogen use Rationalization and Boosting Wheat Productivity by Applying Packages ‎of Humic,Amino Acids,and Microorganisms

ABSTRACT

Integrated management of soil organic matter and nutritional status of crop plants is essential to sustain the production of organic farming systems. Thus, a 2–year field experiment was conducted to examine the effects of soil additions (192 kg N ha^–1, humic+192 kg N ha^–1, humic+144 kg N ha^–1 and humic+96 kg N ha^–1) and foliar applications (amino acids, Azotobacter+yeast, and amino acids plus Azotobacter+yeast) as various fertilizer resources on growth and yield of wheat. Results showed that humic+192 kg N ha^–1 × amino acids plus Azotobacter+yeast were the effective combination for producing the highest values of flag leaf area, total dry weight, tiller number m^–2, spike weight m^–2, and grain yield ha^–1. Under foliar application of amino acids plus Azotobacter+yeast, reducing N supply from recommended rate (192 kg N ha^–1) to 144 kg N ha^–1+ humic achieved higher values of all yield traits, with a saving of 25% of applied mineral nitrogen as well as enhancing nitrogen use efficiency.     

Interactional Impacts of Drought and Weed Stresses on Nutritional Status of Seeds and Water Use Efficiency of Peanut Plants Grown in Arid Conditions

Gesunde Pflanzen - Globally, rationalizing and converting each drop of irrigation water into food is a crucial act in agricultural production, particularly with climatic change concerns....