Dependance of soybean yield on crop evapotranspiration, crop duration and rainfall

In the present study, data for four stations viz., Banswara, Bhopal, Parbhani and Rahuri for the years from 1990 to 1993 have been utilized to understand various aspects of evapotranspiration of the soybean crop. An attempt has also been made to find out the impact of rainfall and crop duration at different phases on the seed yield. The yield was found to be significantly correlated with the rainfall during vegetative phase. Crop growth duration exert positive effect on the soybean yield and that a longer flowering period is favourable for higher yields. The results also indicate that the soybean crop consume maximum water during the vegetative stage.

Identification of High Nitrogen Use Efficiency Phenotype in Rice (Oryza sativa L.) Through Entire Growth Duration by Unmanned Aerial Vehicle Multispectral Imagery

Identification of high Nitrogen Use Efficiency (NUE) phenotypes has been a long-standing challenge in breeding rice and sustainable agriculture to reduce the costs of nitrogen (N) fertilizers. There are two main challenges: (1) high NUE genetic sources are biologically scarce and (2) on the technical side, few easy, non-destructive, and reliable methodologies are available to evaluate plant N variations through the entire growth duration (GD). To overcome the challenges, we captured a unique higher NUE phenotype in rice as a dynamic time-series N variation curve through the entire GD analysis by canopy reflectance data collected by Unmanned Aerial Vehicle Remote Sensing Platform (UAV-RSP) for the first time. LY9348 was a high NUE rice variety with high Nitrogen Uptake Efficiency (NUpE) and high Nitrogen Utilization Efficiency (NUtE) shown in nitrogen dosage field analysis. Its canopy nitrogen content (CNC) was analyzed by the high-throughput UAV-RSP to screen two mixed categories (51 versus 42 varieties) selected from representative higher NUE indica rice collections. Five Vegetation Indices (VIs) were compared, and the Normalized Difference Red Edge Index (NDRE) showed the highest correlation with CNC (r = 0.80). Six key developmental stages of rice varieties were compared from transplantation to maturation, and the high NUE phenotype of LY9348 was shown as a dynamic N accumulation curve, where it was moderately high during the vegetative developmental stages but considerably higher in the reproductive developmental stages with a slower reduction rate. CNC curves of different rice varieties were analyzed to construct two non-linear regression models between N% or N% × leaf area index (LAI) with NDRE separately. Both models could determine the specific phenotype with the coefficient of determination (R2) above 0.61 (Model I) and 0.86 (Model II). Parameters influencing the correlation accuracy between NDRE and N% were found to be better by removing the tillering stage data, separating the short and long GD varieties for the analysis and adding canopy structures, such as LAI, into consideration. The high NUE phenotype of LY9348 could be traced and reidentified across different years, locations, and genetic germplasm groups. Therefore, an effective and reliable high-throughput method was proposed for assisting the selection of the high NUE breeding phenotype.

Fitness consequences of biochemical adaptation in Drosophila melanogaster populations under simultaneous selection for faster pre-adult development and extended lifespan

In holometabolous insects like Drosophila melanogaster, critical size is an important time point during larval life, for irreversible commitment to metamorphosis. Here, we studied the impact of restricted growth duration in terms of selection for faster pre-adult development in Drosophila melanogaster populations which resulted in the evolution of reduced critical size on adult life history traits. Selection for faster pre-adult development resulted in biochemical adaptation in larval physiology with no compromise in major biomolecules at critical size time point. The flies from the selected populations seem to not only commit to metamorphosis on the attainment of critical size but also seem to channelize resources to reproduction as indicated by similar life-time fecundity of CS and NS flies from selected populations, while the Control CS flies significantly lower life-time fecundity compared to Control NS flies. The flies from selected populations seem to achieve longevity comparable to control flies despite being significantly smaller in size-thus resource constrained due to faster pre-adult development.

Aligned vertical growth of zinc oxide nanorods on glass substrates using optimum hydrothermal synthesis technique

<div>This paper reported an optimized hydrothermal synthesis technique to grow zinc oxide (ZnO) nanorods vertically on the normal microscope glass. ZnO nanorods exhibited various advantages such as strong binding energy, non toxicity, large surface to volume ratio and versatility for optical detections. However, the growth of nanorods which aligned vertically on the glass substrates is rather complicated. It required a thorough process based on optimized concentration, growth duration, growth temperature and solvent variations. The morphological structure result has shown an exceptional vertical growth of the nanorods on the glass surfaces which increase the nanorods density. The optimized synthesis technique produced high density ZnO nanorods up to 3 𝑥 10¹³ nanorods/m2 which is double as compared to conventional synthesis technique.</div>

Contrasting yield formation characteristics in two super-rice hybrids that differ in growth duration

Summary The development of high-yielding, short-duration super-rice hybrids is important for ensuring food security in China where multiple cropping is widely practiced and large-scale farming has gradually emerged. In this study, field experiments were conducted over 3 years to identify the yield formation characteristics in the shorter-duration (∼120 days) super-rice hybrid ‘Guiliangyou 2’ (G2) by comparing it with the longer-duration (∼130 days) super-rice hybrid ‘Y-liangyou 1’ (Y1). The results showed that G2 had a shorter pre-heading growth duration and consequently a shorter total growth duration compared to Y1. Compared to Y1, G2 had lower total biomass production that resulted from lower daily solar radiation, apparent radiation use efficiency (RUE), crop growth rate (CGR), and biomass production during the pre-heading period, but the grain yield was not significantly lower than that of Y1 because it was compensated for by the higher harvest index that resulted from slower leaf senescence (i.e., slower decline in leaf area index during the post-heading period) and higher RUE, CGR, and biomass production during the post-heading period. Our findings suggest that it is feasible to reduce the dependence of yield formation on growth duration to a certain extent in rice by increasing the use efficiency of solar radiation through crop improvement and also highlight the need for a greater fundamental understanding of the physiological processes involved in the higher use efficiency of solar radiation in super-rice hybrids.

Early transplanting of rainfed rice minimizes irrigation demand by utilizing rainfall

Background Rainfall is the key contributor to provide soil moisture for wet season rice (T. Aman) cultivation. Erratic rainfall often causes water shortage resulting negative impact on plant growth and grain yield. The study aimed to determine suitable transplanting window that utilize maximum rainfall for T. Aman rice. Firstly, three years field experiment were conducted in Kushtia, Bangladesh from T. Aman, 2013 to 2015, and then the findings were implemented for another two adjacent locations, Panba and Rajshahi. The field experiment considered six transplanting dates of popular cultivar BR11 (growth duration 145 days) at 7 days interval starting from 10 July to 14 August. The CROPWAT 8.0 model was used to calculate crop water requirement (CWR), effective rainfall and irrigation demand (ID) from collected weather data in each growth phase of rice. Results In all locations T. Aman rice received enormous rainfall up to vegetative phase resulting no irrigation demand in all three tested years. The early transplanting received more rainfall in reproductive phase than late planting. Thus, Irrigation demand increased at reproductive phase with delay transplanting in moderate drought prone Kushtia, Pabna and Rajshahi. A significant relationship (R2 = 0.71) observed between reproductive phase ID and grain yield, while grain yield responded weakly with the ID at ripening phase. Based on yield performance 10–24 July found suitable transplanting window for BR11 in Kushtia. Considering the relationship between ID and grain yield, 10–17 July and 10–24 July considered the best transplanting window in Pabna and Rajshahi, respectively. Conclusions Location specific suitable transplanting windows were selected considering minimum ID at reproductive phase and the maximum grain yield. Delay in transplanting demanded more irrigation and reduced grain yield. Whereas, early transplanting utilized maximum rainfall, reduced ID in reproductive stage and ensured desired grain yield.

Response of Crop Water Requirement and Yield of Irrigated Rice to Elevated Temperature in Bangladesh

In the changing climatic condition, temperature is the most vulnerable parameter and is projecting a trend of increase in the future. Crop growth and development process depend largely on air temperature. This study aims to determine the role of increasing air temperature in yield, crop water requirement (CWR), and other agronomic parameters of irrigated rice. Ceres-rice model associated in the Decision Support System for Agrotechnology Transfer (DSSAT) was used in 15 different locations of Bangladesh. Grain yield, growth duration, and crop water requirement of widely cultivated irrigated rice (Boro rice) variety BRRI dhan28 were analysed in normal temperature and elevated air temperature by 1°C, 2°C, 3°C, and 4°C. The result revealed detrimental effect of elevated temperature on growth duration and grain yield. The estimated highest growth duration reduction of 30 days was found in Moulvibazar for 4°C temperature rise. The grain yield reduction was projected by 0–17%, 16–35%, 31–49%, and 39–61% from the normal condition if the seasonal mean temperature increased by 1°C, 2°C, 3°C, and 4°C, respectively. The country average crop water requirement was found to be 405 mm of which the highest 445 mm and the lowest 358 mm were recorded in Moulvibazar and Chandpur, respectively. The study revealed that the country average rice CWR reduced by 5%, 8%, 12%, and 17% over the normal condition for 1°C, 2°C, 3°C, and 4°C rising temperature, respectively. For 1°C temperature rise, BRRI dhan28 life span shortened by 6.4 days, grain yield reduced by 695 kg, and estimated CWR decreased by 14 mm. The projected declining CWR indicated that irrigated rice will require less irrigation water, but it will cause considerable yield loss under elevated temperature. Though elevated temperature will save huge irrigation water used in country-wide Boro rice cultivation, the crop developers need to introduce new heat-tolerant cultivar to minimize yield loss.

Effects of Nitrogen Application on the Growth and Yield of Quinoa under Saline Conditions in Northern Vietnam

This study aimed to determine the optimum nitrogen application rate for quinoa in saline soils. Two experiments were conducted: (i) the first experiment was under artificial saline conditions with the two factors of saline regime (stressed and non-stressed) and nitrogen application level (0, 30, 60, 90 and 150 kg N ha-1) in net-houses located in Gia Lam, Hanoi; and (ii) the second experiment was under natural field saline conditions with the two factors of quinoa cultivar (Atlas and Moradas) and nitrogen application level (0, 30, 60, 90, and 150 kg N ha-1) in the coastal areas of Hai Hau, Nam Dinh province. Data were collected for growth duration, insect and disease infestations during the growth period, and various growth parameters and yield components at harvest. The results showed that saline stress reduced the growth and yield parameters, but did not affect the quinoa growth duration of the investigated quinoa cultivars. In both experiments, the growth parameters and yield components increased according to the increase of the nitrogen application rates from 0 to 90 kg N ha-1, then decreased when the nitrogen rates were higher. The results suggested that 90 kg N ha-1 was the optimum nitrogen application dose for quinoa growth and development under saline soil conditions.