Role of Upland Rice on Sustainability and Food Security of Sugarcane Production System

Abstract. This experiment aimed to study the effects on soil chemical properties of some proceeding crops grown in rotation during the gap period between the last ratoon cane harvest and the next sugarcane planting. The experimental design was RCBD with 4 replications. The implemented treatments were: (i) control (ii) upland rice (iii) soybean and (iv) sunn hemp. During the preceding crops growing period, soils (0-15 cm) were sampled at the week 1, 2, 4, 8 and 16 after planting for soil mineral N analysis. At the final preceding crop harvest, soil samples were collected at 0-15 cm soil depth for chemical analysis and the crops were evaluated for yields, the stovers were collected and incorporated before sugarcane planting. Obtained results revealed that soil in this experiment was sandy soil and low in fertility. During the preceding crops growing period, soil mineral N of all treatments at 0-15 cm soil depth were higher than those before the preceding crop planting, especially upland rice and soybean treatments. At the final harvest, the upland rice treatment had grain yield of 2.86 t ha-1. Soil data at harvest before sugarcane planting indicated that organic matters were not significantly different among treatments. However the upland rice treatment had considerably higher available P content than the other treatments. Moreover upland rice treatment provided the highest exchangeable Ca but it was not significantly different from those in the control and sunn hemp treatments. Thus, upland rice is one of the alternative crops that can be grown as a preceding crop before the next sugarcane planting cycle. It would not only increase the economical income of the farmer but also provide more household food supply and thus might lead to enhance food security in sugarcane cropping system

Screening Tolerance to Phosphorus Deficiency and Validation of <i>Phosphorus Uptake 1</i> (<i>Pup1</i>) Gene-Linked Markers in Thai Indigenous Upland Rice Germplasm

Phosphorus (P) deficiency is a major factor limiting rice yield throughout the world. Fortunately, some rice accessions are tolerant and can thrive well, even in soils with low P content. The ability to uptake P is heritable, and thus can be incorporated into rice cultivars through standard breeding methods. The objective of this study was to screen for tolerance to phosphorus deficiency and validate the tolerant accessions with phosphorus uptake 1 (Pup1) gene-linked markers in Thai indigenous upland rice germplasm. One hundred sixty-eight rice varieties were screened in a solution culture and assigned a phosphorus deficiency tolerance index and plant symptom score. Eleven upland rice accessions (ULR026, ULR031, ULR124, ULR145, ULR180, ULR183, ULR185, ULR186, ULR213, ULR260, and ULR305), together with the lowland rice cultivar (PLD), were classified as tolerant. They were each validated by nine markers linked to the Pup1 locus and observed for the expected polymerase chain reaction (PCR) product of 0 to 9 markers. The presence or absence of the tolerant allele at the Pup1 locus showed only a slight relationship with the tolerance. Moreover, some lines such as ULR183 and ULR213 expressed high tolerance without the Pup1-linked gene product. Both accessions are useful for the exploration of novel genes conferring tolerance to phosphorus deficiency

Interaction between Rhizobacteria and Andrographis paniculata Under Water Limitation

Drought stress is a major agricultural problem that leads to increased accumulation of ethylene in plants. It also has negative effects on plant productivity and growth. Andrographis paniculate is an important herb widely used in medical applications to inhibit diseases caused by viruses. In order to improve the production quality and growth of the A. paniculata, ACC-deaminase plant growth-promoting rhizobacteria were isolated from rice rhizosphere soil. All bacterial isolates were screened for their plant growth-promoting properties, including ACC deaminase, IAA production, biofilm formation, and exopolysaccharide production. Among the bacterial isolates, Rh-01 and Rh-22 exhibited positive results (cutting-edge) in all tests and were identified as Paenibacillus polymyxa Rh-01 and Stenotrophomonas maltophilia Rh-22, respectively. These strains were selected for further pot experiment study. Our results revealed that treatment with chemical fertilizer showed the highest potential to promote A. paniculata seedlings under normal moisture conditions. However, under water limitation conditions, the application of ACC-deaminase plant growth-promoting rhizobacteria led to a higher chlorophyll content compared to the control treatment. In addition, under normal irrigation conditions, plant growth promoting rhizobacterial increased relative water content and total biomass. In terms of plant stress markers, the proline content in Andrographis paniculate’s seedling stage was low under water limitation conditions. In conclusion, to enhance the growth of A. paniculate seedlings during water limitation stress, a combination of microbial biofertilizers and chemical fertilizers is beneficial

Effect of Iron Application on Rice Plants in Improving Grain Nutritional Quality in Northeastern of Thailand

Iron (Fe) deficiency in humans caused by inadequate dietary intake is a global nutritional problem. The field experiments in this paper were conducted in the same paddy field over two consecutive years during the dry seasons of 2017 and 2018. The aims of the experiments were to evaluate the effects of iron application methods (soil or foliar alone and a combination of soil + foliar) on the Fe content in brown rice grain and to compare the grain yields of three rice cultivars, namely Chinat1 (poor Fe grain concentration), Riceberry and Tubtim Chumpae (rich Fe grain concentration). The results show that all iron application methods significantly increase the iron content of brown rice grains in comparison with non-iron application in two cropping years. The iron application to the soil combined with foliar gave the highest iron content in the brown rice grain. However, the responses to the iron application methods were different among rice cultivars. The highest grain iron contents of Chainat1 and Riceberry were shown in the combination of soil and foliar application, whereas Tubtim Chumpae had the highest grain iron content in the foliar application alone. The differences in grain yield were affected by the rice cultivar, but not by iron application methods. The Chainat1 produced the highest grain yield. In addition, Chainat1 had the strongest correlation between brown rice grain iron content and grain yield for both cropping years

Effect of Iron Application on Rice Plants in Improving Grain Nutritional Quality in Northeastern of Thailand

Iron (Fe) deficiency in humans caused by inadequate dietary intake is a global nutritional problem. The field experiments in this paper were conducted in the same paddy field over two consecutive years during the dry seasons of 2017 and 2018. The aims of the experiments were to evaluate the effects of iron application methods (soil or foliar alone and a combination of soil + foliar) on the Fe content in brown rice grain and to compare the grain yields of three rice cultivars, namely Chinat1 (poor Fe grain concentration), Riceberry and Tubtim Chumpae (rich Fe grain concentration). The results show that all iron application methods significantly increase the iron content of brown rice grains in comparison with non-iron application in two cropping years. The iron application to the soil combined with foliar gave the highest iron content in the brown rice grain. However, the responses to the iron application methods were different among rice cultivars. The highest grain iron contents of Chainat1 and Riceberry were shown in the combination of soil and foliar application, whereas Tubtim Chumpae had the highest grain iron content in the foliar application alone. The differences in grain yield were affected by the rice cultivar, but not by iron application methods. The Chainat1 produced the highest grain yield. In addition, Chainat1 had the strongest correlation between brown rice grain iron content and grain yield for both cropping years

Seasonal Variation in Starch Accumulation and Starch Granule Size in Cassava Genotypes in a Tropical Savanna Climate

The information on genotypic responses to the seasonal variation in the starch content, starch yield, and starch quality of cassava is limited. The objective of this research was to investigate the seasonal variation of starch characteristics of three cassava genotypes grown under irrigation. The experiment was conducted at four planting dates (20 April, 30 June, 5 October, and 15 December 2015). Three cassava genotypes (CMR38-125-77, Kasetsart 50, and Rayong 11) were evaluated in a randomized complete block design with four replications and the plants were harvested at 12 months. The planting date contributed the largest portion of the total variation in the starch content, starch yield, and starch granule size. The amylose content variability was heavily influenced by genotype. Cassava planted on 5 October or 15 December had greater starch content, starch yield, and starch granule in most genotypes. This was likely due to a higher temperature and solar radiation during the 3&#8315;9 months post-planting. CMR38-125-77 showed a consistently high starch content, starch yield, and high amylose content for most planting dates except for the starch yield on 20 April, of which Rayong 11 was the best. These findings will be useful for choosing suitable cassava genotypes for different growing seasons and for facilitating breeding efforts for high starch-yielding and high-quality cassava starch in the future

Relationships between Nutrient Uptake and Nitrogen Fixation with Aflatoxin Contamination in Peanut under Terminal Drought

Terminal drought greatly enhanced Aspergillus flavus Link infection (AI) and aflatoxin contamination (AC) in peanut. Identification of new surrogate traits which have an association with AC may be effective to improve peanut varieties with reduced AI and AC. The objective of this work was to examine the relationships of nutrient uptake and N2-fixation (NF) with AC in peanut in a terminal drought condition. Five peanut varieties were tested in well-watered (WW) and terminal drought (TD) conditions (1/3 available water (AW) from R7 (7th reproductive growth stage; beginning of pod maturity stage)). Data were collected for nutrient uptake (nitrogen, phosphorus, potassium, calcium, magnesium), nodule dry weight (NDW), and NF. AI and AC were also examined. Nutrient uptake, NDW, and NF had negative and significant correlations with AI and AC in the TD condition. Negative and significant correlations of the drought tolerance index of nutrient uptake, NDW, and NF with AI and AC were also observed in the TD condition. The results showed that the ability to maintain nutrient uptake and NF in TD might be a mechanism of tolerance to AI and AC. Moreover, due to their negative impacts on AI and AC, nutrient uptake and NF could be used as selection traits for resistance to AI and AC in peanut in TD

Quantitative Evaluation of Macro-Nutrient Uptake by Cassava in a Tropical Savanna Climate

Matching fertilization with crop needs is important for maximizing yields and reducing fertilizer losses. Seasonal variation in nutrient uptake dynamics is poorly understood and thus, the ability to optimize fertilization strategies is limited. This study aims to investigate the effects of planting dates on macronutrient uptake dynamics in cassava genotypes with full irrigation. The performance of cassava genotypes, i.e., CMR38-125-77, Kasetsart 50 and Rayong 11, were evaluated in the early rainy (ERS) and post rainy seasons (PRS) for two years using a randomized complete block design with four replicates. The plants were harvested at 1, 3, 6, 9 and 12 months. Planting dates had significant effects on the accumulation of dry matter and storage roots as well as nutrient uptakes and partitioning. On average, the total nutrient uptake per plant to produce 2831&ndash;3279 g of biomass with 1244&ndash;1810 g of storage roots in the ERS varied among cassava genotypes, ranging from 21.1&ndash;24.3 g N, 5.1&ndash;5.9 g P, 26.5&ndash;29.5 g K, 14.1&ndash;22.2 g Ca, 6.1&ndash;7.6 g Mg and 2.0&ndash;2.3 g S. The total nutrient uptake per plant to produce 3353&ndash;3824 g of biomass with 1604&ndash;2253 g of storage roots in the PRS ranged from 27.1&ndash;32.4 g N, 5.2&ndash;6.0 g P, 29.1&ndash;31.3 g K, 11.9&ndash;20.3 g Ca, 7.3&ndash;9.9 g Mg and 1.2&ndash;1.5 g S. In the ERS, the majority of the total nutrient uptake occurred at the early growth stages, whereas in the PRS, this occurred at the mid- to late growth stages. At final harvest, the percentages of nutrient removal by the storage roots for ERS were 24.7&ndash;36.0% N, 26.0&ndash;32.3% P, 43.4&ndash;51.5% K, 12.4&ndash;17.6% Ca, 22.2&ndash;31.5% Mg and 27.2&ndash;31.5% S, whereas in the PRS the percentages were 30.4&ndash;44.4% N, 33.3&ndash;41.6% P, 44.7&ndash;57.3% K, 12.0&ndash;15.1% Ca, 20.2&ndash;28.1% Mg and 12.0&ndash;25.4% S. CMR38-125-77 exhibited satisfactory performance in nutrient uptake, nutrient use efficiency and storage roots yield across the planting dates. The evidence obtained from this study would greatly facilitate more efficient adoption of precision agriculture in cassava production by applying recommended fertilizers, e.g., rates, kinds and timings, according to crop demand in each growing season in Thailand and for choosing superior cassava genotypes