Introduction of special rice genotypes under upland conditions

Although widely consumed as white rice, there are special rice cultivars that contain aromas, colors and nutrients that reach special market niches, and constitute alternatives to vary the Brazilian menu and the farmer’s income. Most genotypes of special rice have nutritional characteristics superior to those of white rice, with call for better health, which is a growing concern of the general population. Based Based on these assumptions, the objective was to evaluate the productivity of special rice genotypes in rainfed cultivation conditions, in two seasons (2016/2017 and 2017/2018), in the city of Lavras/MG The treatments consisted of the following accessions: YIN LU 31, Japanese, CMG 1164, Formoso, Aromatic, IAC 400, IAC 300, IAC 600, IAC 500, BRSMG Relâmpago, BRSMG Caçula, BRSMG Caravera, SCS119 Ruby, SCS120 Onyx. After analysis of variance, the adaptability analysis and stability was performed by the Annichiaric method. The Aromatic and IAC 300 genotypes, by evaluated under rainfed conditions, showed high productivity (greater than 3,000 kg.ha-1), higher than the state average (867 kg ha-1), and low incidence of diseases in the conditions of high lands. These special rice genotypes grown in upland and compared to cultivars of rice indicated for this cultivation condition demonstrated that it is possible to produce rice from quality and develop genotypes more adaptable to rainfed conditions, which can be excellent option of cultivation to conventional rice and thus increase the diversity of the agricultural property.

Water-stained leaves: formation and application as a field indicator of wetland hydrology

Wetland delineations conducted in the United States utilize field indicators as proxy measures of the presence or absence of wetland hydrology. Water-stained leaves provide a practical, qualitative field indicator of wetland hydrology; however, the formation of water-stained leaves has not been elucidated. In response, leaves from six tree species were examined under five treatments to investigate the water-staining process and concomitant timeframes. Results indicate that leaf staining occurred within 14-21 days of continuous exposure to wetland waters and sediment under both laboratory and field conditions. Leaf staining was characterized by readily observable shifts in leaf color (i.e., decreasing Munsell hue, value, and chroma) causing the leaves to appear very dark or black. No color shifts associated with leaf staining occurred in treatments exposed to upland conditions. The timeframe associated with leaf staining corresponds with established wetland hydrology criteria requiring a minimum hydroperiod of 14 consecutive days of soil saturation, flooding, or ponding. Leaves exposed to wetland waters and sediment underwent color shifts significantly faster and to a greater extent than leaves inundated with deionized water, likely as a result of increased microbial abundance and the presence of anaerobic conditions in the simulated wetland treatments. Results suggest that water-stained leaves 1) are a useful and reliable wetland hydrology field indicator for wetland delineation purposes, 2) may provide a proxy measure of wetland hydroperiod, and 3) Munsell color measurements can help differentiate between leaves exposed to wetland and upland conditions.

Evaluation of Pre and Post Emergence Herbicides in Greengram (Vigna radiata L.) during Kharif and Rabi Seasons in the Uplands of Krishna Zone of Andhra Pradesh

Background: Greengram crop is grown round the year as a catch crop in different cropping systems of the uplands of the Krishna Zone of Andhra Pradesh. The practice of application of pre emergence herbicide like pendimethalin is very popular with the farmers for the control of weeds in the uplands, both in kharif and rabi seasons. Further spraying of a selective post emergence herbicide is also practiced by farmers. However, some of the weeds of kharif viz., Phyllanthus maderaspatensis and rabi viz., Chrozophora rottleri could not be controlled with these herbicides due to their late emergence or due to development of partial resistance to these herbicides. Certain new pre (PE) and post emergence (PoE) herbicides viz., pendimethalin 30% + imazethapyr 2%, acifluorfen sodium 16.5% + clodinafop propargyl 8%, fomesafen 11.1% + fluazifop -p-butyl 11.1%, are recommended in crops like soybean and groundnut. However, there is need to test these herbicides available in market for their suitability to control the weeds in greengram. Methods: A field experiment was carried out at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh, with an objective to evaluate selected PE and PoE herbicide mixtures in greengram managing the major weeds of greengram grown in vertisols of Krishna Zone of Andhra Pradesh during Kharif and rabi seasons of 2018 under upland conditions. Result: Among the two PE herbicides tested on greengram, pendimethalin 30% + imazethapyr 2% @ 0.75 + 0.05 kg/ha was found to be more effective in reducing the weed density and dry matter compared with pendimethalin 30% @ 0.75 kg/ha. The PoE herbicide mixtures tested viz., fomesafen 11.1% + fluazifop -p-butyl 11.1% @111g/ha, propaquizafop 2.5% + imazethapyr 3.75% @ 50+75 g/ha were on par with imazethapyr 10% @ 50g/ha in controlling the weed population without having any adverse affect on the growth and yield of greengram during kharif and rabi.

Present Status and Future Prospects of Drought Tolerance in Rice

Rice is an important staple food crop across the world. It is mainly cultivated under irrigated lowland and also rain-fed upland conditions where drought stress is often noticed. Global climate change predicts an intensification of drought stress in future due to uneven rainfall which was witnessed for the last few years. Confronting drought stress can deliver fruitful crop returns in rice and scope for research extents. Drought stress affects the overall plant growth and yield. A prominent improvement has been made during last two decades in our understanding of the mechanisms involved in adaptation and tolerance to drought stress in rice. In order to achieve the marked crop returns from rainfed areas, there is a requisite of drought tolerant rice varieties, and genetic improvement for drought tolerance should be a prime area of concern in the future. A huge rice germplasm is available and good number of the germplasm possess drought tolerance and these genomic regions have been exploited in developing some drought tolerant rice varieties. The application of available genotyping methodologies, the identification of traits of interest, and key genetic regions associated with the drought tolerance have opened new prospects to successfully develop new drought tolerant varieties. This chapter deals with the importance of drought tolerance in rice crop followed by the evolution of molecular markers and breeding techniques in identifying drought tolerant QTL’s/genes and their utilization in the improvement of drought tolerant rice varieties.

Changes of Cadmium Storage Forms and Isotope Ratios in Rice During Grain Filling

Rice poses a major source of the toxic contaminant cadmium (Cd) for humans. Here, we elucidated the role of Cd storage forms (i.e., the chemical Cd speciation) on the dynamics of Cd within rice. In a pot trial, we grew rice on a Cd-contaminated soil in upland conditions and sampled roots and shoots parts at flowering and maturity. Cd concentrations, isotope ratios, Cd speciation (X-ray absorption spectroscopy), and micronutrient concentrations were analyzed. During grain filling, Cd and preferentially light Cd isotopes were strongly retained in roots where the Cd storage form did not change (Cd bound to thiols, Cd–S = 100%). In the same period, no net change of Cd mass occurred in roots and shoots, and the shoots became enriched in heavy isotopes (Δ114/110Cdmaturity–flowering = 0.14 ± 0.04‰). These results are consistent with a sequestration of Cd in root vacuoles that includes strong binding of Cd to thiol containing ligands that favor light isotopes, with a small fraction of Cd strongly enriched in heavy isotopes being transferred to shoots during grain filling. The Cd speciation in the shoots changed from predominantly Cd–S (72%) to Cd bound to O ligands (Cd–O, 80%) during grain filling. Cd–O may represent Cd binding to organic acids in vacuoles and/or binding to cell walls in the apoplast. Despite this change of ligands, which was attributed to plant senescence, Cd was largely immobile in the shoots since only 0.77% of Cd in the shoots were transferred into the grains. Thus, both storage forms (Cd–S and Cd–O) contributed to the retention of Cd in the straw. Cd was mainly bound to S in nodes I and grains (Cd–S > 84%), and these organs were strongly enriched in heavy isotopes compared to straw (Δ114/110Cdgrains/nodes–straw = 0.66–0.72‰) and flag leaves (Δ114/110Cdgrains/nodes–flag leaves = 0.49–0.52‰). Hence, xylem to phloem transfer in the node favors heavy isotopes, and the Cd–S form may persist during the transfer of Cd from node to grain. This study highlights the importance of Cd storage forms during its journey to grain and potentially into the food chain.

Water management and phenology influence the root-associated rice field microbiota

ABSTRACT Microbial communities associated with plants are greatly influenced by water availability in soil. In flooded crops, such as rice, the impact of water management on microbial dynamics is not fully understood. Here, we present a comprehensive study of the rice microbiota investigated in an experimental field located in one of the most productive areas of northern Italy. The microbiota associated with paddy soil and root was investigated using 454 pyrosequencing of 16S, ITS and 18S rRNA gene amplicons under two different water managements, upland (non-flooded, aerobic) and lowland (traditional flooding, anaerobic), at three plant development stages. Results highlighted a major role of the soil water status in shaping microbial communities, while phenological stage had low impacts. Compositional shifts in prokaryotic and fungal communities upon water management consisted in significant abundance changes of Firmicutes, Methanobacteria, Chloroflexi, Sordariomycetes, Dothideomycetes and Glomeromycotina. A vicariance in plant beneficial microbes and between saprotrophs and pathotrophs was observed between lowland and upland. Moreover, through network analysis, we demonstrated different co-abundance dynamics between lowland and upland conditions with a major impact on microbial hubs (strongly interconnected microbes) that fully shifted to aerobic microbes in the absence of flooding.

Yield Response of Peanut (Arachis hypogaea L.) to Compound Fertilizer

Harahap SM, Ramija KE, Erythrina E. 2020. Yield response of peanut (Arachis hypogaea L.) to compound fertilize. Jurnal Lahan Suboptimal: Journal of Suboptimal Lands 9(1): 41-49.The purpose of this study was to evaluate the application effects of three different compound fertilizers on yield, and assess the income increase at different rates of compound fertilizers. Three compound fertilizers namely NPK 14-0-46, NPK 19-9-19 and NPK 11-11-11 was conducted at three different farmers’ field in Langkat District, North Sumatra Province under upland conditions. In each farmers’ field, a Randomized Complete Block Design was applied with four replications per treatment. Seven treatments tested consisted of full rate of farmer fertilizer practice and six rates of each compound fertilizer plus half rate of farmer fertilizer practice. In each of compound fertilizer tested, pod yield and seed yield increased quadratically as increasing compound fertilizer rates. The highest pod yield and seed yield of peanut were 1649 kg/ha and 1072 kg/ha, respectively with half rate of FFP + 200 kg of NPK 14-0-46. For compound fertilizer NPK 19-9-19 the highest pod yield and seed yield were 1632 kg/ha and 1032 kg/ha with half rate of FFP + 500 kg of NPK 19-9-19 while for compound fertilizer NPK 11-11-11 the highest pod yield seed yield were 1421 kg/ha and 930 kg/ha with half rate of FFP + 250 kg of NPK 11-11-11. However, adding each half rate of farmer fertilizer practices with 200 kg of NPK 14-0-46 or 300 kg of NPK 19-9-19 or 250 kg of NPK 11-11-11 with HypoMa-1 cultivar gave the highest values of the benefit for the farmers under upland soil in Langkat, North Sumatra.