Fertilizer Deep Placement Significantly Affected Yield, Rice Quality, 2-AP Biosynthesis and Physiological Characteristics of the Fragrant Rice Cultivars

The management of fertilizers in a context of climate change and the preservation of the environment is strongly related to the regulation and accumulation of 2-acetyl-1-pyrroline (2AP) in fragrant rice. However, the feasibility of such management strategies in terms of enhancing the accumulation of 2AP has not yet been explored in aromatic cultivars. Here, we investigated the impact of the application of two fertilizers at three depth (surface, 5 cm and 10 cm) levels of placements to improve the aromatic rice quality, including such aspects as the 2AP content-, protein-, amylose- and yield-related traits. For this purpose, two known rice cultivars, Basmati 385 (B-385) and Yunjingyou (YJY), were grown in pots during 2019 and 2020 under fluctuating climates. The deep application of fertilizer at 10 cm significantly affected the 2AP content with such values as 127.53 μg kg−1 and 111.91 μg kg−1 obtained for Fragrant Fertilizer (FF) and Urea in B-385 cultivar, and 126.5 μg kg−1 and 114.24 μg kg−1 being observed for FF and Urea in YJY, respectively, during 2019. In addition, values of 108.41 μg kg−1 and 117.35 μg kg−1 were recorded for FF and Urea in B-385, while 125.91-μg kg−1 and 90.71-μg kg−1 were measured for FF and Urea in YJY, respectively, during 2020. Similarly, B-385 had better 2AP content and yield-related traits, as well as amylose content and cooked rice elongation, as compared to the YJY rice cultivar. The 2AP accumulation and its related biochemical parameters, and their relationships in different plant tissues at different growth stages under FF and Urea treatments, were also improved. Further, the 2AP content and the P5C activity demonstrated strong correlations during the grain filling periods in both fragrant rice cultivars. In conclusion, our findings have the potential to provide useful information to farmers and agriculture extension workers in terms of the saving of fertilizers and the improvement of rice grain quality under fluctuating climate conditions.

Performance of double grained rice cultivar under different plant spacing

Plant spacing ensures uniform and optimum plant population and facilitates sufficient natural resources for crop growth which, in turns influences the crop yield positively. An investigation was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, during July to December 2017 to study the influence of plant spacing on the yield of double grained rice cultivar. The study comprised five spacing viz. 25 cm × 15 cm, 25 cm × 10 cm, 20 cm × 15 cm, 20 cm × 10 cm and 15 cm × 15 cm and two rice cultivars viz. a double grained rice cultivar and BRRI dhan49 and a double grained rice cultivar. It was laid out in a randomized complete block design with three replications. The double grained rice cultivar produced taller plant (155.65 cm), longer panicle (23.93 cm), higher 1000-grain weight (25.96) and higher straw yield (6.90 t ha-1), though the higher grain yield (3.68 t ha-1) was found in the test cultivar (BRRI dhan49). Planting at 20 cm × 15 cm produced the highest grain yield (3.70 t ha-1) which was at par with 25 cm × 15 cm, 25 cm × 10 cm and 20 cm × 10 cm while planting at 15 cm × 15 cm produced the lowest grain yield (3.13 t ha-1). The interaction of the double grained rice cultivar with all spacing combinations produced taller plants than the spacing combinations with BRRI dhan49. The higher grain yield (3.52 t ha-1) was found in the double grained rice cultivar with 20 cm × 10 cm spacing which was at par with the spacing of 20 cm × 15 cm and 25 cm × 15 cm, respectively; although BRRI dhan49 always produced the higher yield. The lowest grain yield (3.08 t ha-1) was recorded at the double grained rice cultivar with 25 cm × 10 cm spacing, however, the same treatment produced the highest biological yield (11.23 t ha-1) due to the highest straw yield (8.15 t ha-1). Hence, the spacing 20 cm × 15 cm might be recommended for the higher grain yield in the double grained rice cultivar Res. Agric., Livest. Fish.8(3): 273-279, December 2021

Application of local microbes increases growth and yield of several local upland rice cultivars of Southeast Sulawesi, Indonesia

Rice is the major food commodity in Indonesia and many other countries, as the main source of carbohydrate. Rice production must be increased continuously to meet food needs, one of which is by utilizing largely available dry land areas. Two important factors required to increase rice production on marginal soils are the use of high-production adaptive varieties and biological agents. It is necessary to conduct research on the application of local microbes to the cultivation of upland rice cultivars, with the aim to determine the best genotypes and/or suitable microbes. This research was carried out at the Research Field and laboratories of Faculty of Agriculture, University of Halu Oleo, from April 2020 to April 2021. The first tested factor was biological agents (local microbes), consisting of three levels, namely: without microbes (M0), the fungus Trichoderma sp. (M1), and the bacteria Pseudomonas sp. (M2). The second factor was the upland rice cultivar, which consisted of five levels, namely: V1 (Tinangge cultivar), V2 (Enggalaru cultivar), V3 (Bakala cultivar), V4 (Momea cultivar), and 1 nasional variety, namely V5 (Inpago-12 variety), as check variety. The research results showed that the interaction between local microbes Trichoderma sp. (M1) and Pseudomonas sp. (M2) on Tinangge (V1) and Momea (V4) cultivars gave a better effect on crop production. The best cultivar based on the growth and yield variables was generally obtained from the Momea cultivar (V4), although in many variables it was not significantly different from the Tinangge cultivar (V1). These cultivars could be further studied and possibly developed for promising cultivars in Kendari areas.

Selenium Decreases the Cadmium Content in Brown Rice: Foliar Se Application to Plants Grown in Cd-contaminated Soil

Cadmium (Cd) contamination in agricultural soils has become a serious issue owing to its high toxicity threat to human health through the food chain. The purpose of this paper is to explore the availability of foliar selenium (Se) application in reducing Cd enrichment in brown rice. A field experiment from 2017 to 2019 was conducted to investigate the effects of foliar Se application on the physiology and yields of three rice cultivars and their accumulation of Cd in low-Cd and high-Cd soils. The grain protein contents and yields of rice plants grown in the high-Cd soil were lower than those of plants cultivated in the low-Cd soil by 27.85% and 6.82%, whereas the malondialdehyde (MDA) and Cd contents were higher by 66.06% and 91.47%, respectively. Se application reduced Cd translocation from the stems and leaves to the spikes, decreasing the Cd content in brown rice by 40.36%. Additionally, Se enhanced the antioxidative activity, glutathione and protein contents, and rice yield (7.58%) and decreased the MDA and proline contents. However, these Se effects weakened under the high-Cd soil. Foliar Se application can alleviate Cd-induced physiological stress in brown rice while improving its yield and reducing its Cd content.