Upland Conditions Research Articles

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.

CoBln 04174: A promising high yielding variety for north east under rainfed upland condition

A promising midlate maturing sugarcane variety, CoBln 04174 was developed at Sugarcane Research Station, Buralikson, Assam from the general collection of C 79180 through clonal selection. The variety was tested in the AICRP trial under different discipline and on farm trials of different agro climatic zones of Assam. The variety CoBln 04174 recorded an average cane yield of 65.54t/ha and sugar yield of 7.63 t/ha with an improvement of 4.58% for cane yield and 3.52% CCS yield over the best standard CoSe 92423 across the centres in two plant crop and one ratoon crop. Besides this, the variety CoBln 04174 recorded average cane yield of 70.4 t/ha which is 22.26% higher over the best standard CoP 9301 (57.58t/ha) in the trials conducted at Sugarcane Research Station, Buralikson. The variety was moderately susceptible to red rot but moderately resistant to borer insect of sugarcane. The variety CoBln 04174 has been identified for release in North Eastern Zone.

Reducing the Risk of Iron Toxicity by Imposing Unsaturated Conditions before Flooding

ABSTRACTUnsaturated incubation (UI) of air-dried soil before flooding significantly reduced the reduction of redox potential and decreased the easily reducible iron (Fe) (ERFe). Antibacterial treatment of the soil decreased the ERFe level regardless of the moisture regime while fungicide treatment reduced the effects of UI. Treating soil under imposed UI with sucrose helped recover the ERFe to the non-UI level. The effects of UI disappeared after air-drying the soil; therefore, the decrease in ERFe—by imposing upland conditions before flooding—could be due to the decrease in the activity of iron-reducing bacteria owing to the depletion of respiratory substrates by bacterial activity during the upland conditions. These results indicate that a drastic change in soil moisture from dry to wet will increase the risk of iron toxicity by increasing the ERFe, but that maintaining an upland condition for more than one week before total submergence can reduce the risk of iron toxicity.

Toward Geodesign for Watershed Restoration on the Fremont-Winema National Forest, Pacific Northwest, USA

Spatial decision support systems for forest management have steadily evolved over the past 20+ years in order to better address the complexities of contemporary forest management issues such as the sustainability and resilience of ecosystems on forested landscapes. In this paper, we describe and illustrate new features of the Ecosystem Management Decision Support (EMDS) system that extend the system’s traditional support for landscape analysis and strategic planning to include a simple approach to feature-based tactical planning priorities. The study area for this work was the Chewaucan watershed of the Fremont-Winema National Forest, located in south-central Oregon, USA. The analysis of strategic priorities recommended five subwatersheds as being of high priority for restoration activities, based primarily on decision criteria related to the stream accessibility to headwaters and upland condition. Among high priority subwatersheds, the most common tactical action recommended was the removal of artificial barriers to fish passages. Other high priority tactical actions recommended in high priority subwatersheds to improve fish habitats were reducing the road density and restoring riparian vegetation. In the discussion, we conclude by describing how the simple tactical planning methods illustrated in this paper can be extended in EMDS to provide a more sophisticated hybrid approach to strategic and tactical planning that can evaluate alternative portfolios of designed management actions applied across landscapes. The latter planned improvement to decision support capabilities in EMDS encapsulates Carl Steinitz’s concept of geodesign.

Near-isogenic lines of IR64 (Oryza sativa subsp. indica cv.) introgressed with DEEPER ROOTING 1 and STELE TRANSVERSAL AREA 1 improve rice yield formation over the background parent across three water management regimes

Three near-isogenic lines (NILs) of Oryza sativa subsp. indica cv. IR64 (Dro1-NIL, Sta1-NIL, Dro1+Sta1-NIL) with DEEPER ROOTING 1 (DRO1), a novel gene for steeper root growth angle, and/or with Stele Transversal Area 1 (Sta1), a QTL for wider stele area, were tested under flooded lowland (FL), alternate wetting and drying lowland (AWD), and rainfed upland (UP) conditions in 2013 and 2014 to compare the effects of DRO1 and Sta1 on yield across different water management regimes. Genotypic variation and water management effects were significant for grain yield, aboveground biomass, and harvest index, as well as their interactions with year, but no significant genotype × water interaction was detected. Dro1-NIL had 14% higher yield than that of IR64 across the three water conditions due to higher harvest index, aboveground biomass, leaf area index, and number of grains. Sta1 tended to reduce the carbon isotope composition (δ13C), leading to a higher harvest index of Sta1-NIL than that of IR64, but grain yield was not increased. Dro1+Sta1-NIL had the highest fraction of intercepted radiation, cumulative radiation interception, and panicle number, with a small but insignificant yield improvement over IR64, but the combination of DRO1 and Sta1 did not surpass the increment from the effects of DRO1 alone. AWD in the more rainy year 2014 attained both higher water productivity and higher biomass, with significant water by year interaction for water productivity. Genotypic variation in water productivity was related with higher leaf area index and fraction interception, with Dro1-NIL larger than in IR64 and Sta1-NIL.

Evaluation of Agrotain Efficiency for Suppression of Ammonium Volatilization Under Chinese Cabbage Cultivation Fields

Chinese cabbage cultivation and ammonia volatilization experiments were done to evaluate the efficiency of Agrotain coated urea (GSP 80% + Agro; GSP 100% + Agro) against conventional urea (GSP 80%; GSP 100%). Fresh weight of Chinese cabbage were 17.2% and 7.3% higher in the treatments that received GSP 80% + Agro and GSP 100% + Agro, respectively, of those from the treatments that received urea alone. Likewise, the nitrogen use efficiency of Chinese cabbage in the treatments that received Agrotain coated urea were significantly higher at the rate of 3.5% (GSP 80% + Agro) and 1.9% (GSP 100% + Agro) compared to urea alone treatments. Ammonia emission was substantially higher at the rate of 107.6 N mg chamber-1 with the application of only GSP 100%. However, nearly 28.3% of ammonia emission was considerably reduced with the use of Agrotain coated urea. Hence, we recommend the use of Agrotain coated urea in conventional farming for increased crop yield as well as simultaneous reduction of nitrogenous fertilizer use.Cumulative ammonia losses from N fertilizer applied soil under upland condition.

Towards Doubling Farm Income: Myths or Reality for the North East Hilly Region

Farming systems in north-eastern states are complex and characterized with high degree of risk and uncertainty. At household level, particularly in upland conditions, the farming systems are highly diverse with multiple crops (mixed cropping), but at aggregate level the cropping pattern is skewed to paddy only. At the aggregate level, the extent of crop diversification appeared quite low in the north-eastern states. But, at the micro-level, the studies indicate the possibility of a very high level of crop diversification, particularly at highland regions. This dichotomy is prevailing in the north-east agriculture. Improvement of farming system through selection and promotion of suitable crop-mix in compliance with the existing socioeconomic as well as topographical situations would certainly enhance farm income. However, those crops were mostly cultivated at a very small scale and the economies of scales were restricted as those farm lands were primarily managed by the family labour and the scope of farm mechanization was limited. There is a growing need for prioritization of sub-sectors with potential of short-term as well as long-term growth and framing strategies to sustain these growths through appropriate institutional support and public- private partnership (PPP). The process will help reduce economic inequality and provide social stability where the voice of local community will be the major guiding force.

Methods of seeding and cultivars effect on weed dynamics in direct-seeded rice under rainfed upland conditions of Nagaland

Field experiments were conducted during Kharif season of 2009 and 2010 to study the effect of methods of seeding and rice cultivars on dynamics of weeds in direct-seeded rice under rainfed upland conditions of Nagaland. Two seeding methods viz., line seeding and broadcasting and four local direct-seeded rice cultivars, viz. ‘Kezie’, ‘Chongloiman’, ‘Leikhumo’ and ‘Kotsala’ were evaluated under the trial in splitplot design. A total of 29 weed species were recorded, out of which Digitaria setigera Roth ex Roem. & Schult, Cynodon dactylon (L.) Pers., Cyperus rotundus Linn., Borreria articularis (L. f.) F. N. Will., Ipomoea triloba L. and Mimosa pudica L. were the dominant weed species. The line sowing was found superior over broadcasting in recording lower density, biomass and relative weed growth rate of grass, sedge and broad-leaf weeds. It also recorded significantly higher grain yield of rice. Among the cultivars, ‘Chongloiman’ and ‘Kezie’ were at par with each other and recorded significantly lower density and biomass of associated grass, sedge and broad-leaved weeds. The highest grain yield during both the years was recorded by the cultivar ‘Chongloiman’ which was at par with ‘Kezie’.

Adaptive Diversity of Echinochloa Species to Osmotic Stress

Three Echinochloa species inhabit various crop fields with different soil moisture conditions. Therefore, a growth pouch test was conducted to investigate adaptive diversity of six Echinochloa species, three from Korea and three from USA, to osmotic stress by assessing shoot and root growths. Echinochloa crus-galli var. praticola showed the greatest tolerance to osmotic stress in both root (GR 50 =1316.3 g PEG L −1 ) and shoot (GR 50 =212.2 g PEG L −1 ) growths, while Korean E. oryzicola was most sensitive to osmotic stress in both root (GR 50 =116 g PEG L −1 ) and shoot (GR 50 =126.2 g PEG L −1 ) growths. Root to shoot (R/S) ratio of Echinochloa crus-galli var. praticola increased with increasing osmotic stress, while that of Korean E. oryzicola decreased, suggesting that R/S ratio is closely related to osmotic stress tolerance in Echinochloa species. Our results clearly demonstrate that E. crus-galli var. praticola maintains high R/S ratio even under high osmotic stress, which enables this species to well adapt to dry upland condition. In contrast, while E. oryzicola fails to maintain sufficiently high R/S ratio, resulting in poor adaptability to dry upland condition.

Varietal differences in the growth responses of rice to an arbuscular mycorrhizal fungus under natural upland conditions

ABSTRACTSeedlings of three rice (Oryza sativa L.) varieties (one indica, ARC5955; and two japonica, Nipponbare and Koshihikari) with or without pre-colonization by the arbuscular mycorrhizal fungus Funneliformis mosseae were transplanted into an upland field and grown to maturity. Pre-colonization had no effect on the yield of Nipponbare or Koshihikari. However, pre-colonized ARC5955 exhibited a strong tendency toward increased yield, which was accompanied by increases in the percentage of ripened grain and the 1000-grain weight. The rice roots were also colonized by indigenous arbuscular mycorrhizal fungi in the field, but these had only limited effects on shoot biomass and grain yields. We speculate that F. mosseae may have exhibited priority effects, allowing it to dominate the rice roots. There was no significant difference in the contents of most mineral elements in the shoots of pre-colonized ARC5955 at harvest, indicating that some other factor is responsible for the observed yield increase.

Effect of Food Waste Compost on Crop Productivity and Soil Chemical Properties under Rice and Pepper Cultivation

Food waste has recognized one of useful sources for potentially agricultural application to supply organic matter and nutrients in arable soil. However, there was little information on application of food waste compost related to the maturity and NaCl content in arable soil. This study evaluated the effect of food waste compost application on yield and fertility in soil under flooding and upland condition. The yields in rice and pepper cultivation decreased with increasing the rate of food waste compost application in soil (p<0.05). Maximum yields of rice (49.0 g plant-1) and pepper (204 g plant-1) were shown at 10 and 30 Mg ha-1 of food waste compost application, respectively. The N, P, and K contents in grain and plant residues increased by the application of food waste compost, there was no difference on Na/K ratio in plant tissue among the treatments. Application of food waste compost resulted in the increase of pH, EC, TC, available P contents in soil after crop harvest, especially, which was shown the increase of the CEC and exchangeable sodium percentage (ESP) contents in irrespective of water condition. In conclusion, application of food waste compost in soil was effective on the supply of the organic matter and nutrient. However, it might need caution to apply food waste compost for sustainable productivity in arable soil because of potential Na accumulation. Yield response in paddy and upland soil applied with food waste compost.

Growth and yield responses of upland NERICAs to variable water management under field conditions

This study aimed to investigate the possible causes for inconsistent performances of upland New Rice for Africa (NERICA) varieties in uplands and lowlands, while identifying important determinants in grain yield under deficient soil moisture. We compared the growth and yield of NERICA 1 and NERICA 5 to those of Yumenohatamochi, a Japanese upland variety, and Hinohikari, a Japanese lowland variety, subjected to different water management regimes (continually flooded, supplementary irrigation, and non-irrigation). Under conditions of deficient soil moisture, panicle number per square meter, spikelet number per panicle, and 1000-grain weight of NERICAs decreased, whereas the panicle number of the Japanese varieties experienced little change. In contrast, the grain filling ratio was unaffected by water management, irrespective of variety. The primary source of yield reduction under low soil water conditions was a decrease in spikelet number per panicle, and water stress intensity was the primary factor for the degree of this reduction. Variation in the abortion of secondary rachis-branches caused differences between NERICAs in their spikelet number response to soil moisture deficiency. The inconsistency in NERICA performance across uplands vs. lowlands can be partially attributed to variation in yield response to low soil water conditions. Moreover, water stress intensity and the presence of a water gradient along the vertical soil profile may combine to affect the fluctuation in NERICA performance under upland conditions.

Allocation patterns contribute to the distributional limits of a flood tolerant ecotype of Chamaecrista fasciculata

To determine factors limiting the distribution of two ecotypes of the annual legume Chamaecrista fasciculata along an abrupt flooding gradient, we quantified the relative importance of tolerance, intra-specific competition, and allocation patterns to vegetative and reproductive functions and their genetic basis. The ecotypes grow in dry upland and freshwater tidal marsh habitat, respectively. Intolerance to flooding limited the upland ecotype from the marsh site, whereas the marsh ecotype had high survival in the upland site. Competition experiments revealed no competitive hierarchy between the two ecotypes under upland conditions. However, the upland ecotype allocated double the proportion of total above ground biomass to reproductive structures compared to the marsh ecotype. In addition, the marsh ecotype produced larger but fewer seeds per fruit than upland ecotype plants. These allocation patterns resulted in the upland ecotype having much greater seed production in the upland habitat. Using a crossing experiment, we quantified the genetic correlation between seed mass and seed number. A negative genetic correlation between seed mass and seed number, as well as a positive genetic correlation with seed mass and shoot elongation of flooded plants suggests that the trade-off in allocation patterns between these two components of reproductive output represents a pleiotropic genetic constraint associated with adaptation to a flooded environment. Thus resource allocation patterns leading to striking trade-offs between above ground vegetative and reproductive allocation appear to limit the marsh ecotype from invading upland habitat.

ON SOME ECOLOGICAL AND BIOLOGICAL FEATURES OF TULIPA BIEBERSHTEINIANA ROEM. ET SCHULT. IN THE TERSKOY UPLAND CONDITIONS OF REPUBLIC OF INGUSHETIA

Aim. The aim of the research is to study the ecological and biological features and evaluation of the current state of coenopopulations of Tulipa biebershteiniana Roem. et Schult. in the Terskoy upland conditions of Republic of Ingushetia (RI), a valuable ornamental species decreasing in number. Methods and materials. T. Biebershteiniana species have been chosen and collected within RI as the material for ecological and biological research. Collection of herbarium material and recording observations, ecological and phenological characteristics of the species have been carried out during two growing seasons (2014-2015) using conventional methods. Result. We have found that on the territory of Ingushetia population of the species Tulipa biebershteiniana Roem. et Schult. can be found only in the area of the Terek ridge on the slopes of the north-western and south-eastern exposures in the vicinity of the rural settlement of Voznesenskaya and Yuzhnoye, in the bushes in a dry clay soils at an altitude of 500-600 meters above sea level sporadically. On the basis of ecological and biological study of features of T.biebershteiniana in terms of its natural habitat we describe ontogenesis and full morphogenesis of its monocarpic shoots. We have also detected the factors limiting its coenopopulations. The growing places of T.biebershteiniana species have been identified, thus we have carried out mapping of its range on the territory of Ingushetia. The soil texture has been studied from natural places of T.biebershteiniana. Conclusion. The research on population status of T. Biebersteiniana on the territory of the Republic of Ingushetia has showed a low density and a limited range of its distribution, and therefore we have made recommendations on taking protective measures of natural spaces of its growth and of making it into the Red Book of the Republic of Ingushetia as a category of III rarity status.

Genetic characterization of introgression lines with the genetic background of the Indica-type rice (Oryza sativa L.) cultivar IR 64 under irrigated lowland and upland conditions

We characterized 333 introgression lines (INLs) harboring chromosome segments from new plant type (NTP) and Japonica-type cultivars with the genetic background of the elite Indica-type rice (Oryza sativa L.) cultivar IR 64, by evaluating yield components and dry matter production under irrigated lowland (IL) and upland (UP) culture in 2011 and 2012; and elucidated the relationships between the traits and chromosome segments introduced from the donors. The panicle weight (PW), PW/total plant weight (PW/TW), number of fertile spikelets (FS), and FS/total number of spikelets per panicle (FS/TS) of the INLs increased, while the culm weight (CW) and panicle number (PN) decreased. Most INLs produced more dry matter in the UP than in the IL culture. The INLs were clustered into three groups (A–C) according to their traits in the UP culture, and four groups (I–IV) according to their traits in the IL culture. They were then sorted into six groups (A-I, A-II, B-II, B-III, C-III, and C-IV) according to the relationships between culture conditions. The INLs of group A-II had increased panicle length (PL), PW, PW/TW, FS, and TS, and these traits were stable in both IL and UP culture. In the other groups, the trait values changed with the conditions and season. Association analyses using trait phenotype and genotype data of SSR markers detected 166 quantitative trait loci (QTLs) for 10 traits, distributed on all chromosomes except 3 and 10. Of these, 81 QTLs for DH, CL, PL, CW, PW, PW/TW, PN, FS, TS, and FS/TS were newly detected. The INLs were characterized under different conditions, and dramatic trait modifications in IR64 rice were associated with these QTLs, through introgression from the donor cultivars. Thus, these INLs and QTLs will be useful in genetic studies to identify the gene(s) that modified IR64, and as breeding materials for genetic improvement of Indica-type cultivars.

Interactions between flooding and upland disturbance drives species diversity in large river floodplains

Understanding and predicting vegetation patterns in floodplains are essential for conservation and/or restoration of river floodplains subject to hydrological alterations. We propose a conceptual hydroecological model to explain the disturbance mechanisms driving species diversity across large river floodplains. These ecosystems harbor a unique set of flood-tolerant species different from the surrounding upland vegetation. In elevation gradients across pristine floodplains, the greater the flooding, the fewer the number of plant species. As terrain elevation increases, flood depth and duration decrease and it is more likely that species composition is influenced by external natural or human-driven disturbances. The spatial interaction between the natural flood regime and upland factors creates patterns of disturbance gradients that influence how floodplain vegetation establishes. In regions where upland conditions are subject to strong external disturbances, species diversity peaks at intermediate stages along the disturbance gradient. We demonstrate this concept with observations from the Central Amazon and Pantanal in Brazil, the Mekong’s Tonle Sap in Cambodia, and the Okavango Delta in Botswana. We discuss how this model could be further elaborated and validated to inform management of large river basins under the impact of upstream-induced flood pulse alterations.

Quantification of Cs, K, and Rb in rice (Oryza sativa) cultivated under paddy and upland conditions

In Asian countries, paddy rice (Oryza sativa) has been cultivated as a main crop for many years, but cesium uptake by rice has only been studied recently. As a result, the effect of land use on cesium uptake by rice is not well understood, and there is little information about the interaction of cesium with alkali metals in the rice–soil system. The objective of this study was to elucidate the stable cesium (Cs), potassium (K), and rubidium (Rb) levels in rice cultivated under paddy and upland conditions and in the soil (a Hapludept). We cultivated 13 rice cultivars (temperate and tropical japonica) under both conditions, and determined the concentrations of Cs, K, and Rb in brown rice and soil (total, exchangeable, and water-soluble fractions) by means of inductively coupled plasma mass spectrophotometry and atomic absorption spectrophotometry. We found that the soil concentrations of water-soluble Cs, K, and Rb were higher under upland conditions than paddy conditions, and Cs and Rb concentrations in brown rice were also higher under upland conditions. The upland conditions may increase soil ion concentrations by water evaporation, and the higher water-soluble Cs and Rb concentrations would increase their concentrations in brown rice. However, more K accumulated in brown rice under paddy conditions. This suggests that the roots absorbed K rather than Cs and Rb from the soil mainly by means of ion diffusion, because paddy conditions would increase ion diffusion but not the soil ion concentration. We conclude that the land use (here, paddy and upland conditions) changed the Cs, K, and Rb levels in the brown rice and soil by different mechanisms because root uptake of these elements would be different.

Influence of Nitrogen Supply on Photosynthesis, Chlorophyll Content and Yield of Improved Rice Varieties under Upland Conditions in Western Kenya

Influence of Nitrogen Supply on Photosynthesis, Chlorophyll Content and Yield of Improved Rice Varieties under Upland Conditions in Western Kenya

Synthesis and herbicidal activity of 3-{[(hetero)aryl]methanesulfonyl}-4,5-dihydro-1,2-oxazole derivative; Discovery of the novel pre-emergence herbicide pyroxasulfone.

Thiocarbamate sulfoxides, which are the active forms of thiocarbamate herbicides, are quickly conjugated with glutathione and decomposed in soil. To achieve more potent and stable herbicidal activity, we previously developed a 5-{[(2,6-difluorophenyl)methoxy]methyl}-5-methyl derivative, which has a 4,5-dihydro-1,2-oxazole ring in place of the thiocarbamate to prevent conjugation and decomposition. Although the derivative showed pre-emergence herbicidal activity under flooded conditions, it displayed no herbicidal activity under upland conditions. In contrast, a 5-(methoxymethyl)-5-methyl derivative showed pre-emergence herbicidal activity against grass weeds under upland conditions. The aim of this study was to obtain a more potent compound with improved physicochemical properties for use as a pre-emergence upland herbicide via the structural optimization of a 3-{[(hetero)aryl]methanesulfonyl}-4,5-dihydro-1,2-oxazole as the core structure. In this way, we have developed the pre-emergence herbicide 3-{[5-(difluoromethoxy)-1-methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl]methanesulfonyl}-5,5-dimethyl-4,5-dihydro-1,2-oxazole, which has been named "pyroxasulfone." This novel compound displayed excellent herbicidal activity against grass and broadleaf weeds under upland conditions with no phytotoxicity against crops.

Identification of a low tiller gene from a new plant type cultivar in rice (Oryza sativa L.).

We characterized a rice introgression line, YTH34, harboring a chromosome segment from a New Plant Type (NPT) cultivar, IR65600-87-2-2-3, in the genetic background of an Indica Group elite rice cultivar, IR 64, under upland and irrigated lowland conditions in Japan. The number of panicles (as an indicator of tiller number) and number of spikelets per panicle of YTH34 were lower than those of IR 64 under irrigated lowland conditions, but both of those as well as culm length, panicle length, seed fertility, panicle weight, whole plant weight, and harvest index were dramatically reduced under upland conditions. And the low tiller of YTH34 was confirmed to start after the maximum tiller stage. In particular, the decrease of panicle number was remarkable in upland, so we tried to identify the chromosome location of the relevant gene. Through segregation and linkage analyses using F3 family lines derived from a cross between IR 64 and YTH34, and SSR markers, we found that low tiller number was controlled by a single recessive gene, ltn2, and mapped with the distance of 2.1 cM from SSR marker RM21950, in an introgressed segment on chromosome 7. YTH34 harboring ltn2 and the genetic information for DNA markers linked will be useful for genetic modification of plant architectures of Indica Group rice cultivar.