Rice Crop Growth Research Articles

Assessment of paddy performance under BGREI initiative using RISAT SAR data

Bringing Green Revolution in Eastern India (BGREI) is a large-scale Department of Agriculture and Co-operation, Ministry of Agriculture (MoA), Government of India funded project with the aim to increase crop productivity through improved package of practices in low-productivity zones of eastern India. Assessment of the BGREI plots with respect to crop vigour variability using space-based observations was planned for 2011–2014 years. A new approach based on Synthetic Aperture Radar (SAR) data was used to assess the rice crop growth pattern and crop vigour. A methodology was developed to evaluate the effect of BGREI programme in the state of Odisha, India. The peak green biomass estimated from SAR data was found to be 10–30% higher in BGREI plots compared to the controlled plots during 2012–2013 and 2013–2014. The improvement was higher in traditionally low productive rainfed zones in coastal and southern Odisha as compared to the irrigated tracts of the northern plateau. Uniformity in growth in terms of growth rate, transplantation time and duration was observed in BGREI plots in both the years, but magnitude was found to be higher in 2012–2013. The impact of the BGREI programme in Odisha indicates that the scheme proved to be a breakthrough in improving rice productivity in low-productivity pockets of eastern India and the SAR-based methodology was able to pickup this with high accuracy.

Conservation agriculture cropping systems reduce blast disease in upland rice by affecting plant nitrogen nutrition

In the central highlands of Madagascar, blast, a serious fungal disease of rice caused by Magnaporthe oryzae, was shown to be less severe in conservation agriculture (CA) than in conventional tillage (CT) cropping systems. To assess the effects of CA cropping systems on rice susceptibility to blast and to understand the mechanisms involved, an experiment was conducted over three growing seasons in two sites (at high and mid-altitude). Two fertilization treatments, one with mineral nitrogen (N) fertilizer, and one without, were studied in interaction with two different cropping systems (CA/CT) and two rice varieties that differ in their susceptibility to blast. The performances of the two cropping systems were assessed, and results showed that yields were no higher in the CA or were lower than in CT cropping systems. The effects of the treatments on upland rice crop growth were measured by leaf N content as an indicator of N crop status, and leaf area index (LAI) as an indicator of canopy density. In all years at both sites, leaf N content during early growth stages was higher in the CT than in the CA cropping system. The LAI was lower in the CA than in the CT cropping system at the high altitude site in all three years, and in two out of three seasons at the middle altitude site. Overall, when the level of blast was high, blast was less severe in the CA cropping system and with no N fertilizer. Leaf N content and LAI were used as intermediate explanatory variables in the statistical analyses, and one or the other or both always masked the effect of the cropping system or of N fertilization. Our results show that leaf N content during early growth stages masks the effect of the cropping system on leaf blast severity. When the LAI is strongly affected by the cropping system, it also masks the effect of the cropping system on the severity of leaf and panicle blast. Very often both variables masked the effects of the cropping system and of N fertilization. These findings should help improve disease management by modifying fertilization practices and crop nutrition in conservation agriculture cropping systems.

Allelopathic Potential of Phyllanthus niruri Linn. on seed Germination and Seedling Growth of Rice (Oryza sativa)

It is known that P. niruri is a member of family Euphorbiaceae. In the previous studies the allelopathy, leachtes of P. niruri have been prepared from root, stem and leaf and their chemical changes have been also recorded. Further studies have been carried out to observe the effect of these leachates on seed germination and seedling growth of rice crop plant. It was observed that there is change in pH value of stem, leaf and root leachtes from first day to six day and different dilutions. The pH value of water is significantly affected by allelochemicals of root during the continuous flow of water and this crop present field to be effected by the water of consisting changed pH value. The effect of these weed on the seed germination and seedling growth of rice crop have been studied and it was found that leachates treatment inhibits the seed germination and seedling growth of crop plants. In the allelopathic study we can show that the root extract of P. niruri Linn. is more effective that of stem and leaf extracts.

PENGARUH INTERAKSI PACLOBUTRAZOL DAN TIPE TANAM JAJAR LEGOWO PADA PRODUKSI PADI METODE TANAM SRI

This study aims to find the effect of interaction of paclobutrazol and type Legowo Row Planting in paddy fields that use SRI cultivation method to increase rice yield, and can determine the best combination of effective and can be applied in paddy fields to increase production. The research was conducted in the Village of Sulu, Tatapaan Sub-district, South Minahasa Regency. This study uses a field experiment with split plot design in groups of two factors. As the first factor is the type of Legowo Row Planting 2: 1 and 4: 1. The second factor is the provision of paclobutrazol by spraying the plants with a dose of: 0 ppm and 600 ppm. Paclobutrazol will be given only once, that when plants in active vegetative growth period (about 30 days old plants after transplanting). Data analysis was used Two-Factor Interactions calculation. The interaction of two factors occured, if the effect of a factor changes when the change level of other factors change. The results indicated that the existence of interaction between treatment paclobutrazol and Legowo row that high interaction in the inhibition of the vegetative growth of rice crops varieties Serayu, middle interactions on the rate of plant growth, middle interactions in the treatment of paclobutrazol and Legowo row to increase the content of chlorophyll a and chlorophyll b in the leaves, the influence of high interaction of the number of productive tillers, high interaction on panicle length, high interaction to the increased weight of 1,000 grains, high interaction of the increase in the weight of dry unhusked rice per plot, and the lack of interaction to increase the number of grains per panicle. Paclobutrazol 600 ppm treatment gave a positive response on Legowo row 2: 1 for the inhibition of vegetative growth of crops to prevent crop is too high and not easily fall, increased chlorophyll a, increasing the weight of 1,000 grains and increased the weight of milled rice per plot. Paclobutrazol 600 ppm treatment gave a positive response on Legowo row 4: 1 to increase the pace of growth, increased chlorophyll b, an increase in the number of productive tiller and panicle length.

Transcription dynamics of Saltol QTL localized genes encoding transcription factors, reveals their differential regulation in contrasting genotypes of rice.

Salinity is one of the major environmental factors affecting the growth and yield of rice crop. Salinity stress response is a multigenic trait and numerous approaches have been used to dissect out the key determinants of complex salt tolerance trait and their regulation in plant. In the current study, we have investigated expression dynamics of the genes encoding transcription factors (SalTFs) localized within a major salinity tolerance related QTL-'Saltol' in the contrasting cultivars of rice. SalTFs were found to be differentially regulated between the contrasting genotypes of rice, with higher constitutive expression in the salt tolerant landrace, Pokkali than the cultivar IR64. Moreover, SalTFs were found to exhibit inducibility in the salt sensitive cultivar at late duration (after 24h) of salinity stress. Further, the transcript abundance analysis of these SalTFs at various developmental stages of rice revealed that low expressing genes may be involved in developmental responses, while high expressing genes can be linked with the salt stress response. Grouping of these genes was well supported by in silico protein-protein interaction studies and distribution of single-nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) in the promoter and genic regions of these genes. Taken together, we propose that out of 14 SalTFs, eight members are strongly correlated with the salinity stress tolerance in rice and six are involved in plant growth and development.

Growth, yield components and grain yield response of rice to temperature and nitrogen levels

An experiment was carried out during the kharif season of year 2013 inside Temperature Gradient Tunnel (TGT) of Centre for Environment Science and Climate Resilient Agriculture (CESCRA), at IARI farm to study impact of elevated temperature on the growth and yield responses of rice crop under four N levels. Results showed that grain and biomass yield of rice had decreased significantly with rise in temperature inside the TGT. With recommended N dose, yield reduction of rice was 37 per cent with rise in temperature to 3.9ºC over ambient air condition but application of 125 per cent N can prevent the yield loss by 6per cent as compared to 100 per cent recommended N treatment. Yield parameters Spikelet sterility of rice did increase with increase in temperature.

FERTILIZATION STRATEGY TO INCREASE RICE GROWTH AND PRODUCTION UNDER TWO FLOODING CONDITION ON TWO LOWLAND SWAMP TYPES

Flood is general phenomenon found in most areas of Indonesia. This can obstruct rice crop cultivation on lowland swamp areas. Fertilization strategy is one of the efforts to increase rice crop growth and production on flooded condition. The objective of this research was to determine the best fertilization strategy on vegetative stage related to rice crop growth and production under flooded condition at two types of lowland swamp. The experimental design used in this research was split-plot design with three replications. The main plot was fertilization treatment consisting of P 1 = base fertilization, P 2 = fertilization before flooded, P 3 = fertilization after flooded and P 4 = fertilization before and after flooded. The subplot was rice variety which consisted of V 1 = Inpara 3, V 2 = Inpara 5, V 3 = IR 64 and V 4 = Ciherang. The results showed that fertilization strategy was capable of increasing rice crop growth and production under flooded condition at two types of lowland swamp. Rice variety Inpara 5 added with fertilizer before flooded on shallow-backswamp and fertilizer addition before and after flooded on middle-backswamp was the best treatment that had produced rice yield with magnitude of 4.48 and 3.43 ton per hectare, respectively.

Over-expression of a DUF1644 protein gene, SIDP361, enhances tolerance to salt stress in transgenic rice

Salt stress has adverse effects on the growth and production of rice crops. In this study, we isolated and characterized SIDP361, which encodes a DUF1644 family protein. This gene was expressed in various rice tissues and was induced by high salt (200 mM NaCl), dehydration, and abscisic acid (100 µM ABA) treatments. Stable expression of SIDP361-GFP in rice cells suggested that SIDP361 is a cytoplasmic protein. When compared with the untransformed wild-type (WT) control, transgenic plants over-expressing SIDP361 exhibited significantly improved tolerance to salt stress at both the seedling and heading stages. Under salinity conditions, the transgenics also had elevated amounts of free proline. Moreover, transcript levels for genes encoding proline synthetase enzymes were significantly higher in transformants than in the WT. The transgenic lines were also hypersensitive to exogenous ABA. Quantitative real-time PCR analysis showed that transcription of several stressrelated genes was greater in SIDP361-overexpressing plants than in the WT under both normal and salt-stressed conditions. These results demonstrate that SIDP361 has high potential as a tool for genetically improving salt tolerance in rice.

Stimulate The Growth of Rice Using Endophytic Bacteria from Lowland Rice Plant Tissue

Exploration and selection of endophytic bacteria from healthy food crops grown in lowland ecosystem is important to be conducted in order to get growth-stimulating endophytic bacteria at soil with low fertility level so that capable to optimize initial growth of food crops and subsequently can increase productivity level of lowland soil.The research objective was to isolate and to test the IAA-producing endophytic bacteria isolate in stimulating the rice crop growth at lowland area. Endophytic bacteria are isolated from tissues of rice, corn and peanut crops which grown at shallow swamp land in Ogan Ilir and Ogan Komering Ilir Districts, South Sumatra, Indonesia. There was nine isolates of nitrogen-fixer endophytic bacteria that capable to contribute IAA phytohormone into their growth media. The P31 isolate from rice crop tisssue of 2 months old produce the best rice sprouts than other isolates. This isolate can contribute of about 10 mg kg -1 IAA to its growth medium and increase the crowns dry weight and the roots dry weight respectively with magnitudes of 133% and 225% compared to control treatment. Concentration and absorbtion of N for rice crops innoculated with P31 isolates had increased by 169% and 400%, recpectively. The P31 isolates had been identified as Burkholderia pseudomallei (also known as Pseudomonas pseudomallei) .

PERTUMBUHAN DAN HASIL PADI SAWAH ORGANIK DENGAN MENGGUNAKAN PUPUK KANDANG SAPI DAN AZOLLA

<p><em>Farmyard manure and a</em><em>zolla</em><em> </em><em>are</em><em> </em><em>potential</em><em> sources of organic fertilizer in </em><em>organic </em><em>paddy field</em><em>. This study aimed to determine the effect of using </em><em>farmyard manure and </em><em>azolla</em><em> on </em><em>growth and yield of</em><em> </em><em>rice</em><em> crop. The research method was field trial in </em><em>an </em><em>organic paddy field,</em><em> Sukorejo Village, Sragen, Indonesia. Experimental design which used was a completely randomized block design with 9 kinds of treatment which are repeated in 3 blocks. </em><em>Th</em><em>ese kind of treatments were the using</em><em> of farmyard manure, azolla fertilizer, azolla inoculum, and the combinations </em><em>which is based on</em><em> </em><em>the fulfillment of</em><em> nutrient requirements of 120 kg N ha<sup>-</sup><sup>1</sup>. </em><em>Farmyard</em><em> manure significantly increase</em><em>d</em><em> the fresh weight of </em><em>biomass</em><em> (two-way ANOVA F = 3.13 p <</em><em> </em><em>0.05), the weight of grains per panicle (two-way ANOVA F = 3.36 p <</em><em> </em><em>0.05) and dry grain harvest (two-way ANOVA F = 3.71 p <</em><em> </em><em>0.05). Azolla fertilizer significantly increase</em><em>d</em><em> </em><em>the </em><em>plant height (two-way ANOVA F = 2.93 p <</em><em> </em><em>0.05). Meanwhile azolla inoculum </em><em>did not give</em><em> significant effect on all parameters (both growth and yield). Dry grain harvest </em><em>has </em><em>very </em><em>significant correlation </em><em>with </em><em>plant height (0.68<sup>**</sup>); fresh weight of </em><em>biomass</em><em> (0.79<sup>**</sup>); weight of grains per panicle (0.61<sup>**</sup>)</em><em>;</em><em> and grain weight of 1,000 seeds (0</em><em>.</em><em>48<sup>*</sup>). The result of F test and correlation analysis showed that </em><em>farmyard</em><em> manure significantly increase</em><em>s</em><em> the dry grain harvest through its role on increasing</em><em> </em><em>the weight of fresh </em><em>biomass</em><em> and grain weight per panicle. Azolla fertilizer also significantly increase</em><em>d</em><em> </em><em>the dry grain harvest through its role on increas</em><em>ing the</em><em> plant height. However, the effect of Azolla fertilizer to increase the dry grain harvest </em><em>was </em><em>weaker than </em><em>farmyard</em><em> manure.</em></p>

Validation of the AquaCrop model for irrigated rice production under varied water regimes in Bangladesh

Crop growth simulation models of varying complexity have been developed to predict the effects of soil, water, nutrients and climate on biomass and grain yields and water use efficiency of different crops. In this study, the AquaCrop model was calibrated and validated for rice crop growth modeling under different irrigation water regimes at the Bangladesh Rice Research Institute, Gazipur, Bangladesh during the 2008–09 and 2009–10 winter (dry) seasons. Three irrigation water regimes were examined: irrigation with continuous standing water (CSW), and irrigation at 3 or 5 days after water disappearance (3 or 5 DAWD) from the field as potential water saving adaptations. Model performance was evaluated in terms of prediction error (Pe), coefficient of determination (R2), the normalized root mean squared error (NRSME), the Nash–Sutcliffe model efficiency coefficient (EF) and Willmott’s index of agreement (d). The model calibration yielded 0.94<R2<0.99, 14.5<NRMSE<21.6, 0.83<EF<0.95 and 0.97<d<0.99 in simulating canopy cover (CC) percentage and above-ground biomass. Model validation yielded 0.98<R2<0.99, 8.6<NRMSE<12.9, 0.94<EF<0.97 and d=0.99 in simulating CC percentage and above-ground biomass. In calibration and validation, respectively, the prediction errors for grain yield varied from 5.55 to 7.70% and 8.22 to 11.54%, and for biomass production from 2.62 to 5.19% and 7.95 to 11.15%, indicating good model performances. Based on crop yield, water use and its use efficiency, the IR69515-KKN-4-UBN-4-2-1-1 genotype showed better productivity in the dry season under the 3 DAWD irrigation water regime compared to the other examined treatments, which was shown by both the experimental data and the model simulations using FAO recommended conservative model parameters. The FAO AquaCrop model was able to predict rice growth and yield with acceptable accuracy under different water regimes, making this model a suitable candidate to facilitate local scenario studies related to irrigation scheduling, yield prediction or studies related to climate change and adaptation.

Wheat Residue Management Options Affect Crop Productivity, Weed Growth, and Soil Properties in Direct‐Seeded Fine Aromatic Rice

Wheat residue management can influence soil health, weed growth, and productivity of subsequent rice crop. A field study was conducted to appraise the influence of different wheat residue management options viz., surface mulching of wheat residue (SMWR), wheat residue soil incorporation, wheat residue burning, zero tillage (ZT), and surface seeding on weed growth, soil physico‐chemical properties, and productivity of fine aromatic rice crop. Traditional transplanted rice (TPR) was maintained as control. The response of rice yield and its components including the number of productive tillers, grains per panicle and 1000‐grain weight differed significantly under the influence of various residue management options. SMWR recorded the highest grain yield (3.86 t ha−1) after TPR (4.18 t ha−1). Furthermore, the leaf area index and crop growth rate were also higher in SMWR and TPR compared with other treatments. Residue management options had a significant effect on weed population and dry biomass. A minimum weed density was observed in TPR (33–39 plants m−2) followed by SMWR (78–93 plants m−2). Available phosphorus in the experimental soil of TPR and SMWR treatments was increased by 74 and 45% compared to its initial value. Moreover, other soil attributes like organic matter, available potassium, and soil nitrogen were also improved by the application of wheat residue. Conclusively, SMWR was the best treatment for direct‐seeded rice among the residues management options in terms of final yield, weed burden, and improvement of soil health, although nitrogen and organic matter was higher under ZT.

Rice Crop Monitoring and Yield Assessment with MODIS 250m Gridded Vegetation Products: A Case Study of Sa Kaeo Province, Thailand

Abstract. Billions of people in the world depend on rice as a staple food and as an income-generating crop. Asia is the leader in rice cultivation and it is necessary to maintain an up-to-date rice-related database to ensure food security as well as economic development. This study investigates general applicability of high temporal resolution Moderate Resolution Imaging Spectroradiometer (MODIS) 250m gridded vegetation product for monitoring rice crop growth, mapping rice crop acreage and analyzing crop yield, at the province-level. The MODIS 250m Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) time series data, field data and crop calendar information were utilized in this research in Sa Kaeo Province, Thailand. The following methodology was used: (1) data pre-processing and rice plant growth analysis using Vegetation Indices (VI) (2) extraction of rice acreage and start-of-season dates from VI time series data (3) accuracy assessment, and (4) yield analysis with MODIS VI. The results show a direct relationship between rice plant height and MODIS VI. The crop calendar information and the smoothed NDVI time series with Whittaker Smoother gave high rice acreage estimation (with 86% area accuracy and 75% classification accuracy). Point level yield analysis showed that the MODIS EVI is highly correlated with rice yield and yield prediction using maximum EVI in the rice cycle predicted yield with an average prediction error 4.2%. This study shows the immense potential of MODIS gridded vegetation product for keeping an up-to-date Geographic Information System of rice cultivation.

Bistatic measurements for the estimation of rice crop variables using artificial neural network

An outdoor rice crop bed (4×4m2) was specially prepared for a bistatic ground based scatterometer measurements at various growth stages of rice crop from transplanting to ripening stage at like polarizations (HH- and VV-) in the angular range of 20–70° at the steps of 5°. The computed scattering coefficients showed increasing behavior from transplanting to reproductive stage and started decreasing at ripening stage. The angular dependency of scattering coefficient was found to decrease initially with age and became negligible near the ripening stage of rice crop. The polynomial regression analysis showed higher values of coefficient of determination (R2) at 30° incidence angle for both like polarizations. Two types of feed forward back propagation neural network (FFBPNN) models were developed for the estimation of rice crop growth variables namely FFBPANN-I and FFBPANN-II model. The FFBPANN-I model was developed with one input neuron (HH- or VV-polarized scattering coefficient) and one output neuron (biomass or leaf area index or plant height or chlorophyll content) while the FFBPANN-II model was developed with two input neurons (HH- and VV-polarized scattering coefficient) and four output neurons (biomass, leaf area index, plant height and chlorophyll content). Performances of both the types of FFBPANN models were found good for the estimation of rice crop variables. However, the performance of FFBPANN-II model was found better in comparison to the FFBPANN-I model at suitable incidence angle 30°.

Effects of steel slag application on greenhouse gas emissions and crop yield over multiple growing seasons in a subtropical paddy field in China

Asia is responsible for over 90% of the world's rice production and hence plays a key role in safeguarding food security. With China being one of the major global producers and consumers of rice, achieving a sustainable balance in maximizing crop productivity and minimizing greenhouse gas emissions from paddy fields in this country becomes increasingly important. This study examined the effects of applying steel slag, a residual product derived from the steel industry, on crop yield and CH4 and N2O emissions over multiple growing seasons in a Chinese subtropical paddy field. Average CH4 emission was considerably higher during the periods of rice crop growth compared to that during the periods of fallowing and vegetable crop growth, regardless of the amount of steel slag applied. When compared to the controls, significantly lower mean emissions of CH4 (1.03 vs. 2.34mgm−2h−1) and N2O (0.41 vs. 32.43μgm−2h−1) were obtained in plots with slag addition at a rate of 8Mgha−1 over the study period. The application of slag at 8Mgha−1 increased crop yields by 4.2 and 9.1% for early and late rice crops, respectively, probably due to the higher availability of inorganic nutrients such as silicates and calcium from the slag. Slag addition had no significant effect on the concentrations of heavy metals in either the soil or the rice grains, although a slight increase in the levels of manganese and cobalt in the soil and a decrease in the levels of manganese and zinc in the rice grains were observed. Our results demonstrate the potential of steel slag as a soil amendment in enhancing crop yield and reducing greenhouse gas emissions in subtropical paddy fields in China, while posing no adverse short-term impacts on the concentrations of heavy metals in the soil or the rice grains. However, long-term implications of this management practice and the cost/benefit remain unknown, so further studies to assess the suitability at large scale are warranted.

Monsoon paddy monitoring and assessment using synthetic aperture radar data under BGREI programme in Odisha, India

Bringing green revolution in eastern India (BGREI) is an initiative of Department of Agriculture and Co-operation (DAC) Ministry of Agriculture (MoA), Govt. of India with the aim of increasing crop productivity through improved inputs and package of practices in seven states of eastern India comprising the low productivity zones. The current study aimed at assessment of the BGREI plots with respect to crop vigour variability using space-based observations. Synthetic aperture radar (SAR) data were used to assess the rice crop growth pattern and vigour through change in backscatter response. A SAR-based methodology was developed to evaluate the effect of BGREI initiative in the state of Odisha. The peak biomass, an indicator of crop vigour was 15–30 % higher in BGREI plots compared to the controlled plots. The improvement was higher in traditionally low productivity rainfed zones. Uniformity in growth in terms of growth rate, transplantation time and duration was observed in BGREI plots. The positive effect of BGREI in Odisha indicates that BGREI may be a breakthrough in improving rice productivity in low productivity zones of eastern India .

Comparative Study of Susceptible and Tolerant Genotype Reveals Efficient Recovery and Root System Contributes to Heat Stress Tolerance in Rice

In changing climate scenario, heat stress caused by increased atmospheric CO2 is a major concern for rice productivity. There is a need to decipher the mechanisms of heat stress susceptibility and tolerance response of rice cultivars considering that high temperature is detrimental to growth and development of rice crop. The present study was designed to understand the heat stress response in heat-susceptible (Vandana) and heat-tolerant (N22) cultivars of rice. Rice seedlings were subjected to short-duration (24 h, SDS) and long-duration (5 days, LDS) heat stress (42 °C/36 °C, day/night). Besides the heat stress, recovery response (REC) of both the cultivars was also studied. Physiological parameters (chlorophyll content and membrane thermostability) and root/shoot length analysis revealed that N22 has better efficiency in recovering from heat stress. In particular, root tissue of N22 showed increased thermotolerance during SDS and LDS when compared with Vandana. In addition to physiological studies, gene expression pattern of 13 genes including heat shock transcription factors and heat shock proteins and 9 microRNAs (miRNAs) was analyzed in root and shoot of both the genotypes during various treatments. Gene and miRNA expression studies showed that root tissue of N22 was more responsive during SDS and LDS, suggesting important function of roots in heat stress tolerance. Further, during recovery, root tissue of both the genotypes showed more significant change in gene expression than shoot which signifies the vital role of plant root system in heat stress recovery response. Very high expression of an unknown iron-sulfur cluster-binding protein OsFd involved in electron transport activity was observed in root tissue of N22 during all the stress treatments. This study shows that better recovery and efficient root system play an important role in heat tolerance trait of N22.

Influence of Efficient, Multicomponent, Polyfunctional, Physiologically Active (Nano) Chips with Herbicide Activity on Rice Crop Growth, Development, Yield and on Weed Growth Inhibition

Using physiologically active, complex, polyfunctional, multicomponent (nano) systems – (nano) chips in the pre-sowing rice treatment (nano) technology allows precise seeding; enhancing field seed germination; reducing plant morbidity rate considerably or even deleting disease incidents; increasing plant adaptability to unfavorable environmental conditions; expanding crop yield; improving products quality by not using toxic chemical means of plant protection; intensifying competitive ability of agricultural products as well as assuring environmental safety in crop cultivation regions. Nutrition micro- and mesoelements, as also intense activity plant growth regulators and other physiologically active substances, depending on the crop variety, cultivation conditions and possible risks, can be added to such pre-sowing treatment (nano) technology.

Food preferences of the multi-mammate mouse, Mastomys natalensis, in irrigated rice habitats in Tanzania

We investigated the composition of the diet of the multi-mammate mouse, Mastomys natalensis, within irrigated rice and fallow field habitats at set time periods related to rice crop growth stages. In both habitats, vegetative plant material, i.e. leaves, stems and seeds, were the most abundant components of the rodent's diet, while other food types (invertebrates, fruits) were observed only in low quantities. We conclude that vegetative plant material and seeds were the main types of food consumed not only due to their relatively higher abundance in the environments under study but also because of the highly specialised herbivorous/granivorous nature of the dominant rodent species, M. natalensis. Thus, the introduction and expansion of continuous rice-cropping using irrigation in Tanzania is likely to be severely constrained by the presence of M. natalensis. In our opinion, field hygiene, including the removal of alternative food resources and nesting sites for M. natalensis near cropping areas, may help to both lower rodent population numbers and reduce immigration potential. Non-chemical rodent control methods such as trap barrier systems developed for lowland irrigated rice in south-eastern Asia should, we argue, be evaluated for their effectiveness under African conditions.

Influence of Efficient, Multicomponent, Polyfunctional, Physiologically Active (Nano) Chips with Herbicide Activity on Rice Crop Growth, Development, Yield and on Weed Growth Inhibition

Using physiologically active, complex, polyfunctional, multicomponent (nano) systems – (nano) chips in the pre-sowing rice treatment (nano) technology allows precise seeding; enhancing field seed germination; reducing plant morbidity rate considerably or even deleting disease incidents; increasing plant adaptability to unfavorable environmental conditions; expanding crop yield; improving products quality by not using toxic chemical means of plant protection; intensifying competitive ability of agricultural products as well as assuring environmental safety in crop cultivation regions. Nutrition micro- and mesoelements, as also intense activity plant growth regulators and other physiologically active substances, depending on the crop variety, cultivation conditions and possible risks, can be added to such pre-sowing treatment (nano) technology.