Planting date and fertilizer type influenced soil quality indices and soybean (Glycine max L.) yields in derived savannah of Nigeria

Soybean is grown in many parts of Northern Nigeria, with little climatic challenges and soil organic matter. There is need to investigate possible influence of planting date of the crop in Southeastern Nigeria, an environment that is rather foreign to the crop. A study was carried out in 2018 and 2019 cropping seasons at Federal College of Agriculture, Ishiagu, Ebonyi State, to evaluate the influence of different planting dates and fertilizer types on selected soil physical and chemical properties, growth and yield of soybean. A split plot in a randomized complete block design was used with planting date (May and June) as the main plots, while six fertilizer types (poultry-droppings manure 5 t ha–1, swine-droppings manure 5 t ha–1, rice-husk dust 5 t ha–1, NPK 15:15:15 at 150 kg ha–1, urea at 100 kg ha–1 and the control) constituted the sub-plots. At crop maturity, some soil quality indices and pod and grain yields (t ha–1) of soybean were assessed. Soil organic carbon (SOC) and total nitrogen contents were significantly (p < 0.05) influenced by both planting date and fertilizer type in 2018 and 2019, while soil pH was improved significantly (p < 0.05) only by fertilizer type in these two cropping seasons. Mean-weight diameter of aggregates, soil bulk density and SOC stock as well as soybean yields were significantly (p < 0.05) influenced by both planting date and fertilizer type in the two seasons. Generally, planting in May improved soil total nitrogen and soybean pod yield whereas planting in June improved the other soil quality indices and soybean grain yield, the best soil amendment in either case being poultry-droppings manure but sometimes parameter-specific. The choice of planting date (May or June) in soybean production in the derived savannah and the soil amendment to use in the enterprise thus has both agronomic and environmental implications. Such a choice would depend on the indices of soil quality and/or the aspects of soybean yields (pod or grain) whose improvements the farmer intends to achieve at crop maturity.

A Review on Rice Straw Management Strategies

Rice straw is one of the organic materials and natural residue of rice crop or paddy material and is the third-largest residue from agriculture after sugarcane bagasse and maize straw. Southeast Asian countries produce approximately 80% of rice production in the world. It leads to a large quantity of rice straw as a by-product every year. Surplus rice straw is a focal issue associated with storage of rice straw, removal of entire straw from the field, and very little time between the cultivation of the crop. Stubble burning is a quick, cheap, and efficient way to prepare the soil bed for wheat, the next crop. Rice straw has both nutrient and calorific values. Straw is the only organic material available in significant quantities to most rice farmers. About 40 percent of the nitrogen (N), 30 to 35 percent of the phosphorus (P), 80 to 85 percent of the potassium (K), and 40 to 50 percent of the sulfur (S) taken up by rice remains in vegetative plant parts at crop maturity. Straw is either removed from the field, burned in situ, piled or spread in the field, or incorporated in the soil. Open burning of the crop residue kills useful microflora of soil, leads to soil degradation, and contributes to harmful greenhouse gases such as SO2, NO2, CH4, N2O, carbon monoxide in the atmosphere including the hydrocarbon and particulate matter. Therefore, rice straw burning is a serious creator of environmental pollution. The study investigated environment-friendly options of rice straw such as bedding material for cattle, mushroom cultivation, nutrition in the soil, power generation, combustion material, pellet making, bio-gas, bio-ethanol, bio-char, acoustic material, 3D objects, cardboard and composite board, packaging materials, production of bio-composite, cement bricks, and handmade paper. The key purpose of this paper is to provide environmentally friendly alternatives to rice straw instead of open field burning.

Fine-Tuning Florigen Increases Field Yield Through Improving Photosynthesis in Soybean

Crop yield has been maintaining its attraction for researchers because of the demand of global population growth. Mutation of flowering activators, such as florigen, increases plant biomass at the expense of later flowering, which prevents crop maturity in the field. As a result, it is difficult to apply flowering activators in agriculture production. Here, we developed a strategy to utilize florigen to significantly improve soybean yield in the field. Through the screening of transgenic lines of RNAi-silenced florigen homologs in soybean (Glycine-max-Flowering Locus T Like, GmFTL), we identified a line, GmFTL-RNAi#1, with minor changes in both GmFTL expression and flowering time but with notable increase in soybean yield. As expected, GmFTL-RNAi#1 matured normally in the field and exhibited markedly high yield over multiple locations and years, indicating that it is possible to reach a trade-off between flowering time and high yield through the fine-tuning expression of flowering activators. Further studies uncovered an unknown mechanism by which GmFTL negatively regulates photosynthesis, a substantial source of crop yield, demonstrating a novel function of florigen. Thus, because of the highly conserved functions of florigen in plants and the classical RNAi approach, the findings provide a promising strategy to harness early flowering genes to improve crop yield.

Growth and Yield of Late Season Cauliflower (Brassica oleracea var. botrytis L.) Varieties in Mid-hill Region of Nepal

Background: Cauliflower production during the late winter season has major problems including the requirement of long duration for its maturity, lower yield and poor postharvest quality, especially in the mid-hill region of Nepal. A field experiment was conducted to access the growth, crop maturity and yield of late-season cauliflower varieties at Puranchaur, Kaski in the mid-hill region of Nepal.Methods: The experiment was arranged in a randomized complete block design (RCBD) with toal eleven late-season cauliflower varieties in which nine were hybrid varieties viz. Freedom, Titan, Ravella, Artica, Bishop, Casper, Indam 9803, NS 106 and Snow Mystique while two were open pollinated varieties viz. Amazing and Snowball 16. The experiment was conducted from November 2016 to March 2017 with four replications.Result: Significantly shorter period for final curd initiation of 76 days was recorded in NS 106 and Indam 9803 which was statistically similar with Amazing. Significantly shorter period for final curd maturation of 90 days was recorded in Amazing which was statistically similar to Bishop and NS 106. Similarly, the highest curd yield of 50 mt/ha was produced by Bishop at 91 days after transplanting (DAT) while the lowest crud yield of 19 mt/ha was recorded in Snowball 16 at 113 DAT. Finally, it was concluded that Bishop found the best hybrid variety for higher curd yield and short duration for maturation while Amazing performed higher yield than Snowball 16 and early maturing variety in the mid-hill region of Nepal.

Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 1: broadleaf species

Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter phenology in thirteen economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after physiological maturity at multiple sites spread across fourteen states in the southern, northern, and mid-Atlantic U.S. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate increased at northern latitudes. Amaranthus species seed shatter was low (0 to 2%), whereas shatter varied widely in common ragweed (Ambrosia artemisiifolia L.) (2 to 90%) over the weeks following soybean physiological maturity. Overall, the broadleaf species studied shattered less than ten percent of their seeds by soybean harvest. Our results suggest that some of the broadleaf species with greater seed retention rates in the weeks following soybean physiological maturity may be good candidates for HWSC.

Prediction of Winter Wheat Maturity Dates through Assimilating Remotely Sensed Leaf Area Index into Crop Growth Model

Predicting crop maturity dates is important for improving crop harvest planning and grain quality. The prediction of crop maturity dates by assimilating remote sensing information into crop growth model has not been fully explored. In this study, a data assimilation framework incorporating the leaf area index (LAI) product from Moderate Resolution Imaging Spectroradiometer (MODIS) into a World Food Studies (WOFOST) model was proposed to predict the maturity dates of winter wheat in Henan province, China. Minimization of normalized cost function was used to obtain the input parameters of the WOFOST model. The WOFOST model was run with the re-initialized parameter to forecast the maturity dates of winter wheat grid by grid, and THORPEX Interactive Grand Global Ensemble (TIGGE) was used as forecasting period weather input in the future 15 days (d) for the WOFOST model. The results demonstrated a promising regional maturity date prediction with determination coefficient (R2) of 0.94 and the root mean square error (RMSE) of 1.86 d. The outcomes also showed that the optimal forecasting starting time for Henan was 30 April, corresponding to a stage from anthesis to grain filling. Our study indicated great potential of using data assimilation approaches in winter wheat maturity date prediction.

Antixenosis, Antibiosis, and Potential Yield Compensatory Response in Barley Cultivars Exposed to Wheat Stem Sawfly (Hymenoptera: Cephidae) Under Field Conditions

Wheat stem sawfly, Cephus cinctus Norton, is an economically serious pest of cereals grown in North America. Barley cultivars were previously planted as resistant crops in rotations to manage C. cinctus, but due to increasing levels of injury to this crop, this is no longer a valid management tactic in Montana. Therefore, we aimed to understand antixenosis (behavioral preference), antibiosis (mortality), and potential yield compensation (increased productivity in response to stem injuries) in barley exposed to C. cinctus. We examined these traits in eight barley cultivars. Antixenosis was assessed by counting number of eggs per stem and antibiosis was assessed by counting infested stems, dead larvae, and stems cut by mature larvae. Potential yield compensation was evaluated by comparing grain yield from three categories of stem infestation: 1) uninfested, 2) infested with dead larva, and 3) infested cut by mature larva at crop maturity. We found the greatest number of eggs per infested stem (1.80 ± 0.04), the highest proportion of infested stems (0.63 ± 0.01), and the highest proportion of cut stems (0.33 ± 0.01) in ‘Hockett’. Seven out of eight cultivars had greater grain weight for infested stems than for uninfested stems. These cultivars may have compensatory responses to larval feeding injury. Overall, these barley cultivars contain varying levels of antixenosis, antibiosis, and differing levels of yield compensation. Our results provide foundational knowledge on barley traits that will provide a framework to further develop C. cinctus resistant or tolerant barley cultivars.

Evaluation of Tillage, At-Planting Treatment, and Nematicide on Tobacco Thrips (Thysanoptera: Thripidae) and Reniform Nematode (Tylenchida: Hoplolamidae) Management in Cotton

There are numerous early-season pests of cotton, Gossypium hirsutum L., that are economically important, including tobacco thrips, Frankliniella fusca (Hinds), and reniform nematode, Rotylenchulus reniformis (Linford & Oliveira). Both of these species have the potential to reduce plant growth and delay crop maturity, ultimately resulting in reduced yields. A field study was conducted during 2015 and 2016 to evaluate the influence of tillage, at-planting insecticide treatment, and nematicide treatment on pest management, cotton development, and yield. Treatment factors consisted of two levels of tillage (no-tillage and conventional tillage); seven levels of at-planting insecticide treatments (imidacloprid, imidacloprid plus thiodicarb, thiamethoxam, thiamethoxam plus abamectin, acephate plus terbufos, aldicarb, and an untreated control); and two levels of nematicide (no nematicide and 1,3-dichloropropene). There were no significant interactions between tillage, at-planting insecticide treatment, or nematicide for any parameters nor was there a difference in the main effect of nematicide on thrips control or damage. The main effects of tillage and at-planting insecticide treatment impacted thrips densities and damage. The no-tillage treatments and aldicarb in-furrow or acephate seed treatment plus terbufos in-furrow significantly reduced thrips populations. Early-season plant response was impacted by tillage and at-planting insecticide treatment; however, that did not result in significant yield differences. In regard to nematicide treatment, the use of 1,3-dichloropropene resulted in lower yields than the untreated.