Effect of different fertilizer doses on the production of Chaite-5 paddy variety in Dhanusha District, Nepal

The application of inorganic nutrient sources is necessary for proper agricultural growth that can ensure high quality food production. A field experiment was carried out in Hansapur, Dhanusha from March 2021 to July 2021 to study the effect of different fertilizer doses on the growth and yield of rice. The experiment was set up in a randomized complete block design (RCBD) with 7 different treatments following three replications. The treatments were named as T1: Control, T2: RDF (Recommended dose of fertilizers - 100:30:30 kg NPK/ha), T3: Double dose of RDF (200: 60: 60 kg NPK/ha), T4: A half dose of RDF (50: 15: 15 kg NPK/ha), T5: 125% dose of RDF (125: 37.5: 37.5 kg NPK/ha), T6: Locally available Azolla (300 kg/ha), and T7: FYM (6 ton/ha), respectively. Different doses of RDF showed a significant effect on growth, yield, and yield contributing characters of Chaite-5 variety. Results of the study showed that the application of a double dose of RDF (200: 60: 60 kg NPK/ha) gave the maximum yield (9.50 ton/ha). It was also recorded that 125% dose of RDF, recommended dose of fertilizers and FYM gave satisfactory results. Results revealed that the highest plant height, effective tillers/hill, panicle number, panicle length, total spikelet/hill, 1000-grain weight, grain yield, and straw yield were obtained from the use of a double dose of RDF (200: 60: 60 kg NPK/ha). It was observed that yield of rice can be increased substantially with the application of higher doses of nitrogenous fertilizers. Hence, a double dose of fertilizer can be the best supplement for improving growth and yield in rice.

Increased Number of Spikelets per Panicle Is the Main Factor in Higher Yield of Transplanted vs. Direct-Seeded Rice

With increasing water shortages and labor costs, rice planting is gradually undergoing a transformation from traditional transplanting to direct seeding. However, the yield of direct-seeded rice is unstable and the reasons for this instability are disputed. Therefore, we established a field experiment conducted over 3 years to investigate the reasons for the difference in rice yield under different planting methods. The planting methods compared were transplanting (TR), broadcast sowing (BS), and sowing in line (SL). The yield of rice under TR was higher (10,390 kg ha−1) than that of BS (7790.7 kg ha−1) and SL (9105.2 kg ha−1). Given that the harvest index showed little variation among the three planting methods, the yield differences reflected that shoot dry matter production under TR was higher. Two reasons for the latter observation are suggested: (1) the planting density under TR was lower than that under BS and SL, thus competition for nutrient resources would have been reduced; (2) the growth period of TR was longer. The higher shoot dry matter accumulation under TR contributed to enhanced panicle number per m2 and number of spikelets per panicle than under BS. A significant correlation between number of spikelets per panicle and yield was observed. Although yield was highest under TR, the costs under TR were the highest among the three planting methods. In contrast, the benefit-to-cost ratio under SL was higher than that of TR and BS. The higher yield under TR reflected the production of larger spikelets per panicle than those produced under direct-seeding methods. However, the benefits of SL are conducive to enhanced profitability of rice production.

Evaluating the implementation of fertilizer-based decision support systems to increase yield productivity and efficiency of irrigated rice farming in West Java

Nutrient management and fertilizer application are paramount elements for increasing rice productivity. However, most of farmers are still applying fertilizer in an improper way and hence economic benefit of the yield remain low. The objective of this study was to examine various fertilizer recommendations and hence the best and efficient dose of fertilizer can be obtain to increase growth and yield of rice. This experiment was conducted in farmers irrigated lowland Sukabumi, West Java in dry season 2019. The material used was high yielding IR-64 rice variety subjected to six fertilizer recommendation, namely urea only (A), LKP (B), factory’s recommendation (C), PUTS, (D), KATAM (E) and farmer’s practice (F). This experiment was arranged in randomized block design (RBD) with four replications. The quantitative morphological and physiological traits and financial analysis were observed. The result showed that fertilizer significantly affected morphological, physiological parameters and grain yield of rice. PUTS and KATAM (9,7t/ha) treatments had higher grain yield compared to other treatments. Fertilizer by farmer’s practice tended lower in morphological, physiological and grain yield responses compared to other fertilizer recommendation. Similar pattern showed for yield components such as panicle number, grains number and % empty grain were also affected by fertilizer recommendation. Based on the financial analysis that treatment with LKP fertilizer recommendation had higher profit (75.61%) compared with farmer’s practice. That treatment can reduce fertilizer costs by 61.57%, can increase revenue by 14.04% and give a profit of Rp. 5,580,969,-.

Performance of six new superior varieties of rice on tidal swamp-land in South Kalimantan Province

Rice is the staple food for millions of people of Indonesia which produced from many agroecology including tidal-swamp. The contribution of swampland to the national rice production is still lower than 2%. One of the indigenous knowledge of the tidal-swamp farmers is the massive use of local varieties which have low yield. Therefore, efforts to increase rice production in tidal-swampland of Barito Kuala Regency should consider the use of superior varieties. The purpose of this study was to find out performance of seven superior varieties in tidal-swamp land in two planting seasons. This research was conducted from March 2020 to March 2021 in Karang Buah Village of Belawang District of Barito Kuala Regency, South Kalimantan Province. The research was arranged in two factors of Randomized Complete Block Design namely varieties and seasons. The first factor consisted of seven varieties: Inpari-42 (V1), Inpari-43 (V2), Inpari IR Nutri Zinc (V3), Inpara-8 (V4), Inpara-9 (V5), Inpara-10 (V6), and IR-42 (V7). The second factor, season consisted of season-1 which started from March to July 2020 and season-2 for planting period from November 2020 to March 2021. The result showed that swamp rice varieties had higher value for plant height variables than those of irrigated rice varieties with Inpari-8 as the highest one. However, all irrigated rice varieties performed better which had higher value for panicle number, filled rice grain, and yield with IR-42 as the highest one. All varieties except IR-42 showed higher values of filled grain numbers when cultivated in season-1 supported by good weather during the study.

Yield, Grain Quality and Starch Physicochemical Properties of 2 Elite Thai Rice Cultivars Grown under Varying Production Systems and Soil Characteristics

Rice production systems and soil characteristics play a crucial role in determining its yield and grain quality. Two elite Thai rice cultivars, namely, KDML105 and RD6, were cultivated in two production systems with distinct soil characteristics, including net-house pot production and open-field production. Under open-field system, KDML105 and RD6 had greater panicle number, total grain weight, 100-grain weight, grain size, and dimension than those grown in the net-house. The amounts of reducing sugar and long amylopectin branch chains (DP 25–36) of the RD6 grains along with the amounts of long branch chains (DP 25–36 and DP ≥ 37), A-type starch granules, and average chain length of the KDML105 were substantially enhanced by the open-field cultivation. Contrastingly, the relative crystallinity of RD6 starch and the amounts of short branch chains (DP 6–12 and DP 13–24), B- and C-type granules, and median granule size of KDML105 starch were significantly suppressed. Consequently, the open-field-grown RD6 starch displayed significant changes in its gelatinization and retrogradation properties, whereas, certain retrogradation parameters and peak viscosity (PV) of KDML105 starches were differentially affected by the distinct cultivating conditions. This study demonstrated the influences of production systems and soil characteristics on the physicochemical properties of rice starches.

Genetic Diversity of Shanlan Upland Rice (Oryza sativa L.) and Association Analysis of SSR Markers Linked to Agronomic Traits

Shanlan upland rice, a kind of unique rice germplasm in Hainan Island, was used to evaluate genetic diversity and association between SSR markers and agronomic traits. A total of 239 alleles were detected in 57 Hainan upland rice varieties using 35 SSR markers, and the number of alleles per locus was 2-19. The observed heterozygosity was 0.0655-0.3115. The Shannon diversity index was 0.1352-0.4827. The genetic similarity coefficient was 0.6736-0.9707, and 46 varieties were clustered into one group, indicating that the genetic base of the Shanlan upland rice germplasm was narrow. A total of 25 SSR markers significantly related to plant height, effective panicle number per plant, panicle length, total grain number, filled grain number, seed rating rate, and 1000-grain weight were obtained ( P < 0.01 ), with the percentage of the total variations explained ranging from 0.12% to 42.62%. RM208 explained 42.62% of the total variations in plant height of Shanlan upland rice. RM493 was significantly associated with 6 agronomic traits. We can speculate that RM208 may flank QTLs responsible for plant height and RM493 may flank QTLs playing a fundamental role in the intertwined regulatory network of agronomic traits of Shanlan upland rice.

Down-expression of TaPIN1s Increases the Tiller Number and Grain Yield in Wheat

Background Tiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum). Auxin plays an important role in the regulation of branch production. PIN-FORMED 1 (PIN1), an auxin efflux carrier, plays a role in the regulation of tiller number in rice (Oryza sativa); however, little is known on the roles of PIN1 in wheat. Results Nine homologs of TaPIN1 genes were identified in wheat, of which TaPIN1-6 genes showed higher expression in the stem apex and young leaf in wheat, and the TaPIN1-6a protein was localized in the plasma membrane. The down-expression of TaPIN1s increased the tiller number in TaPIN1-RNA interference (TaPIN1-RNAi) transgenic wheat plants, indicating that auxin might mediate the axillary bud production. By contrast, the spikelet number, grain number per panicle, and the 1000-grain weight were decreased in the TaPIN1-RNAi transgenic wheat plants compared with those in the wild type. In summary, a reduction of TaPIN1s expression increased the tiller number and grain yield per plant of wheat. Conclusions Phylogenetic analysis and protein structure of nine TaPIN1 proteins were analyzed, and subcellular localization of TaPIN1-6a was located in the plasma membrane. Knock-down expression of TaPIN1 genes increased the tiller number of transgenic wheat lines. Our study suggests that TaPIN1s is required for the regulation of grain yield in wheat.

Correlation and Path Analysis of Yield and Related Traits of Upland Rice Genotypes across Weeding Regimes

This investigation was carried out at International Institute of Tropical Agriculture IITA, Ibadan, Nigeria to estimate correlation coefficients of yield and associated traits of thirty-six upland rice lines and the effect of these attributes in four weeding regimes. The weeding regimes were: weed free, weeding twice (21 and 42 days after sowing (DAS), weeding once at 42 DAS only, and weeding once at 21 DAS only, laid out in an alpha lattice design replicated two times. Correlation analysis indicated that yield was significantly and positively associated with panicle length, panicle number and 100 seed weight in both years. There was also a highly significant negative correlation between weed dry matter at all the sampling periods and number of tillers, plant height at maturity in 2011 and number of panicles and panicle length in 2012. Weed dry matter was negatively correlated with grain yield (P < 0.01) in both years clearly explaining the adverse effect of weed on the yield of rice. Path analysis revealed that days to 50% flowering, 100 seed weight, number of panicles and panicle length had direct positive effect on yield across the weeding regimes. Hence, selection based on these traits could help bring simultaneous improvement of yield and yield attributes. For further breeding activities, more emphasis should be given to 100 seed weight, days to 50% flowering, number of panicles and panicle length as they showed high correlation in addition to maximum direct positive effects on yield.

Heading Uniformity: A New Comprehensive Indicator of Rice Population Quality

Productive tiller percentage (PTP) is the only available comprehensive indicator of rice population quality. However, productive panicle number (PN) has a great effect on its characterization accuracy. Panicle exsertion is an important but difficult to describe morphological index; therefore, it cannot be easily determined. The aims of this study were to develop heading uniformity (HU), which describes the difference in the degree of rice panicle exsertion, as a new comprehensive indicator by designing a representative sampling and calculation method and exploring the relationship between HU and yield components. HU first decreased then increased after initial heading, exhibiting a single-valley curve. Adequate HU was obtained by panicle sampling on day two or three (panicle N fertilizer proportion ≤40 or >40%) after initial heading. The explanatory power of PTP for grain yield variance was markedly insufficient in low- and high-PN rice populations. Compared with the percent contribution of PTP to grain yield variance (12.32–41.26%), that of HU (49.02–61.93%) was greater and more stable across rice populations of different PNs. Moreover, HU showed fewer interannual variations, despite large interannual differences in weather and soil conditions. Hence, HU may have applications as a comprehensive indicator of rice population quality.

Influence of Nano Silicon and Nano Selenium on Root Characters, Growth, Ion Selectivity, Yield, and Yield Components of Rice (Oryza sativa L.) under Salinity Conditions

Rice production under salinity stress is a critical challenge facing many countries, particularly those in arid and semi-arid regions. This challenge could be handled by applying novel approaches to overcome yield limiting factors and improve resource use efficiency. The usage of nanoparticles (NPs) could be a beneficial approach to managing the growing problem of soil salinity. The aim of our study was to investigate the advantageous effects of soaking and foliar application of silicon (Si) and selenium (Se), (NPs-Si at 12.5 mg L−1 and NPs-Se at 6.25 mg L−1) on root characteristics, moropho-physiological traits, and yields of two rice varieties (i.e., Giza 177 as a salt sensitive and Giza 178 as a salt tolerant) grown in saline soil compared to untreated plants (control treatment). Results showed that soaking NPs-Se resulted in the highest value of root thickness for Giza 178 (0.90 mm, 0.95 mm) and root volume (153.30 cm3, 154.30 cm3), while Giza 177 recorded 0.83 mm, 0.81 mm for root thickness and 143.30 cm3, 141.30 cm3 for root volume in the 2018 and 2019 seasons, respectively. Soaking NPs-Se, NPs-Si and foliar application of NPs-Se at BT resulted in the highest relative water content and dry matter, while foliar application of NPs-Si at BT gave the highest leaf area index of rice plants compared to the other treatments. Giza 178 (i.e., salt tolerant variety) significantly surpassed Giza 177 (i.e., salt sensitive variety) in the main yield components such as panicle number and filled grains/ panicle, while Giza 177 significantly exceeded Giza 178 in the panicle weight, 1000-grain weight, and unfilled grains number/ panicle. Soaking NPs-Se and foliar application of NPs-Si at BT resulted in the highest grain yield of 5.41 and 5.34 t ha−1 during 2018 and 5.00 and 4.91 t ha−1 during 2019, respectively. The salt sensitive variety (Giza 177) had the highest Na+ leaf content and Na+/K+ ratio as well as the lowest K+ leaf content during both seasons. Applying nano nutrients such as NPs-Si and NPs-Se improved the yield components of the salt sensitive variety (Giza 177) by enhancing its ion selectivity. Both NPs-Si and NPs-Se had almost the same mode of action to mitigate the harmful salinity and enhance plant growth, and subsequently improved the grain yield. In summary, the application of NPs-Si and NPs-Se is recommended as a result of their positive influence on rice growth and yield as well as minimizing the negative effects of salt stress.