Late Transplanting Research Articles

Effect of sowing date and planting method on yield and yield components of three varieties of quinoa (Chenopodium quinoa Willd)

The most important parameter for the adaptability a crop to different climates is the sowing date, as this has the greatest influence on the phonological characteristics of the plant. This study was conducted to determine the potential yield of different quinoa varieties sowed at various dates in hot and dry climates. The experiment was conducted as a split-plot experiment based on a randomized complete block design with four replications over two crop years, 2018–2019 and 2019–2020. The sowing date was considered as the main factor at four levels (October 21, October 31, November 10 and November 20), the sowing method (transplanting and seed sowing) as the sub-factor and the quinoa varieties (Gizal, Q26 and Titicaca) as the sub-sub-plot. The results showed that delays in sowing date reduced leaf area index (LAI), plant height, grain yield components, grain yield and biological yield of quinoa. The highest values for these traits were recorded for the first sowing date of October 21. Late transplanting was superior to direct seed sowing. Among the varieties studied, the Q26 variety was superior to the other two varieties in terms of growth, yield components and grain yield. The highest grain yield (2786 kg/ha) was recorded direct sowing on October 21 and the lowest (896 kg/ha) for under direct sowing on November 20 and 30, respectively. Overall, early autumn sowing was suitable for growing different quinoa varieties in the Khuzestan province due to the longer growing period and avoidance of heat stress at the end of the growing period. Transplanting did not have much advantage over early seed sowing, but was better than delayed seed sowing.

Interactive effect of transplanting time and crop phenology on incidence of brown planthopper and spider population in rice (Oryza sativa)

Brown planthopper (BPH), Nilaparvata lugens (Stal 1854) is a destructive insect pest causing severe yield loss every year in rice (Oryza sativa L.) crop. An experiment was conducted during during kharif (rainy) seasons of 2021 and 2022 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi to study the effect of transplanting time and crop phenology on brown planthopper (BPH) incidence and spider population in rice. BPH and spider populations were recorded at different phenological stages in early, normal and late transplanted rice. Results showed that a significantly higher mean BPH population was observed in late transplanting in 2021 [54.00±5.31 per hill (nymphs and adults)] and 2022 (40.40±2.62 per hill) compared to normal and early tranplanting. Peak BPH population was observed at the heading (225.60±18.83 per hill) and milking stage (131.00±8.30 per hill) of late transplanted rice in 2021 and 2022, respectively. Likewise, more mean spider population was observed in late transplanting [1.87±0.11 per hill (adults) in 2021 and 2.38±0.08 per hill in 2022]. Two-way ANOVA showed a statistically significant interaction between transplanting time and crop phenology with regard to BPH incidence and spider population in both the years. The highest grain yield was recorded in early transplanted rice (36.08±0.75 q/ha; 35.06±0.49 q/ha) followed by normal (27.53±0.80 q/ha; 28.22±0.75 q/ha) and late transplanted rice crop (17.43±0.82 q/ha; 19.37±0.67 q/ha) respectively during two years. The early transplanted rice crop escaped the peak BPH incidence resulted in increased grain yield. The study demonstrated that both transplanting time and crop phenology influenced the BPH and spider populations.

Morpho-physiological and phenological response of rice (Oryza sativa L.) genotypes to low temperature stress at reproductive stage

The yearly changes in atmospheric temperature are projected to negatively affect food production in several locations. Rice exposure to low-temperature stress can decrease plant growth in different stages, notably during the reproductive period. A field experiment was conducted in ARS Gangavathi, Karnataka. The experiment laid out in factorial randomized block design where four different rice genotypes (GNV-10-89, GNV-1801, GNV-1108 and BPT-5204) transplanted under two different dates of transplanting D1 (normal Kharif-15th September) and D2 (late Kharif-30th September). The low temperature during the reproductive stage was 14.1°C which inhibited the morphological, physiological, phenological and yield traits of rice crop. All the observations were recorded at the flowering stage (95 DAT). The results revealed that morphological traits like plant height, number of green leaves, number of productive tillers, total dry matter, total leaf area and root length were high in D1 than D2 (101.6 & 99.76 cm, 21.5 & 16.1 hill-1, 14.5 & 11.5 hill-1, 29.0 &21.1 g hill-1, 3.79 & 4.11 dm2 hill-1 and 14.6 & 18.2 cm), physiological traits such as photosynthetic rate (14.55 & 13.45 µ mole CO2 m-2 s-1) and Transpiration rate (12.86 & 11.01 m mole H2O m-2 s-1) similarly phenological traits, DPI (80.6 & 90.5 days), DF (98.3 & 102.3 days), DPM (116.7 & 127.2 days) and DHM (124.7 & 135.4 days). Reproductive traits like pollen viability (91.3 & 87.4 %) and spikelet fertility (84.3 & 75.9 %) and grain yield (7744.8 & 6531.3 kg ha-1). Among the genotypes GNV-10-89 (10270.9 kg ha-1) recorded the higher grain yield and lower was observed in BPT-5204 (3937.5 kg ha-1) these results conclude that the late Kharif transplanting was not suitable for this region as there was sharp drop-down of temperature (14.1°C) at a reproductive stage which leads to high spikelet sterility. By looking at the results obtained, among four genotypes GNV-10-89 recorded high grain yield followed by GNV-1108 these two genotypes are considered as moderately tolerant, GNV-1801 is moderately sensitive and BPT-5204 is sensitive to low-temperature stress.

Optimization of Irrigation Water to Maximize Transplanted Aman Rice Production in Selected Areas of Bangladesh

In rainfed and irrigated agriculture, optimization of irrigation scheduling is very essential to maximize the crop production using the limited of agricultural water resources. A study was conducted to estimate requirement of irrigation and its scheduling of T. Aman (wet season) rice in the Northwest and Southeast region of Bangladesh using CROPWAT model. This paper utilized the daily rainfall and reference evapotranspiration data sets, obtained from seven weather stations for the period of 1981 to 2015. Effective rainfall and reference crop evapotranspiration (ETo) were calculated using the USDA Soil Conservation method and Penman-Monteith method, respectively. The simulation model of this explored the appropriate transplanting date to utilize maximum rainwater and to avoid supplemental irrigation. Four transplanting dates 15 July, 30 July, 15 August and 30 August were considered for transplanting T. Aman rice in the study areas. The optimization results showed that the water requirement was lower of the rice crop transplanting on 15 July in all locations due to higher effective rainfall. No supplemental irrigation was required for T. Aman cultivation transplanted on 30 July in Rangpur, Dinajpur, Bogura and Mymensingh regions since rainfall was sufficient to meet the demand of the crop. Therefore, this period was found for suitable and recommended for transplanting of T. Aman rice in these four locations. Transplanting after 30 July in these four locations needed supplemental irrigations. This study also revealed that 30 July transplanting required one supplemental irrigation in Jashore and Rajshahi regions due to insufficient rainfall. This period was also considered as the appropriate transplanting time in these two locations. However, in Pabna, one supplemental irrigation must be applied for T. Aman even transplanting on 15 July owing to in adequate rainfall. Irrigation requirement and number of irrigations were gradually increased with delaying the transplanting time. Early transplanting demanded less irrigation than late transplanting. Bangladesh Rice J. 25 (2) : 11-20, 2021

Grain Yield and Water Productivity of Irrigated Rice Affected by Transplanting Dates in Bangladesh

Selection of suitable transplanting window is essential for getting desired crop yield and optimizing irrigation water. This study was conducted in four different locations of Bangladesh (Gazipur, Mymensingh, Cumilla and Bogura districts) to investigate the effect of transplanting period on irrigation water productivity during irrigated rice (Boro) cultivation. Ceres-rice model incorporated in DSSAT was used to estimate rice grain yield and agronomic parameters for Boro 2016-17. Daily weather data and soil data were collected from Bangladesh Meteorological Department (BMD) and Soil Resource Development Institute (SRDI). The estimated irrigation scheduling using CROPWAT- 8.0 model was used as input to the DSSAT model. Rainfall distribution showed only about 22% (2% in winter and 20% in pre-monsoon) of annual rainfall occurred in irrigated rice growing period. Delay transplanting after 15 December, the cultivar BRRI dhan28 faced higher mean daily temperature resulted shorter life span. The increased seasonal mean temperature by 2.8ºC in Gazipur and Bogura and 2.6ºC in Mymensingh and Cumilla from 15 December to 01 March reduced growth duration by 24 days in Gazipur, Mymensingh and Bogura and by 26 days in Cumilla district. Cumilla received the maximum rainfall, however Gazipur experienced the lowest among the four study locations. The received rainfall amount increased with the advancement of transplanting date from 15 December. The increased rainfall reduced the irrigation demand of the cultivar. On the contrary, reduced growth duration due to delay transplanting decreased the grain yield. Transplanting up to 1 February produced almost similar grain yield, while irrigation demand decreased from 15 December transplanting. Water productivity showed increasing trend for late transplanting. Considering grain yield and irrigation water productivity, 15 January to 1 February transplanting were found suitable transplanting period for the study locations. Rice crop establishment within the recommended period could be optimized the grain yield and irrigation water productivity in the selected study locations. Thus, maximum coverage of rainfall can be reduced the irrigation demand. Consequently, it may help to optimize groundwater use and to arrest the groundwater mining. Bangladesh Rice J. 25 (2) : 21-30, 2021

Nitrogen and density treatment to improve resource utilization and yield in late sowing <italic>japonica</italic> rice

<p id="C3">Recently, the phenomenon of late sowing and late transplanting in rice is becoming more and more common in central Jiangsu, a rice and wheat double cropping system area, which is caused by climate change and the expanding of comprehensive rice-and-shrimp planting model. It will lead to the mismatch of rice growth period with light and temperature resources, restricting the stable high yield of rice. This study was conducted under the condition of late sowing and late transplanting (sowing date was June 12th, transplanting date was June 30th) and the seedling was transplanted by machine. Four nitrogen application rates (N₀: 0 kg hm^-2; N₂₄₀: 240 kg hm^-2; N₃₀₀: 300 kg hm^-2; N₃₆₀: 360 kg hm^-2) and three density treatments (D₃: 3 seedlings per hole; D₄: 4 seedlings per hole; D₅: 5 seedlings per hole) were arranged, and the suitable sowing period (May 29), conventional nitrogen application rate, and the seedling number per hole (N₃₀₀D₄) were taken as the controls. Our goal is to explore the effects of nitrogen fertilizer and seedling number per hole on the growth and yield formation in late-sown <italic>japonica</italic> rice, and to provide theoretical basis for improving yield potential and resource use efficiency in late sowing and late transplanting <italic>japonica</italic> rice in central Jiangsu province. The results showed that compared with CK, the yield of each treatment decreased, mainly because of the significantly reduced spikelet number under the late sowing and late transplanting condition. The highest spikelet numbers were 11.94% and 8.12% lower than those of CK in the two years. In addition, the utilization rate of temperature and light resources, nitrogen uptake, and nitrogen utilization rate decreased under late sowing and late transplanting treatment, leading to a decrease in dry matter accumulation and yield. The yield increased with the increase of nitrogen application rate and seedling number per hole under the late sowing and late transplanting condition, while there was no consistent with the trend under N₃₆₀D₅ treatment. We assumed that it was mainly due to the increased spikelet number, larger leaf area index at heading stage, the larger proportion of efficient leaf, and the extended growth period. In summary, the utilization of temperature and light resources and the dry matter accumulation at maturity stage was improved, and the decline in yield was alleviated. Nitrogen use efficiency increased first and then decreased with the increase of nitrogen rate, and N₃₀₀D₅ treatment reached the maximum. In general, under the late sowing and late transplanting condition, in order to alleviate the yield loss and reduce nitrogen fertilizer waste, we should increase the seedling number per hole and then increase the amount of nitrogen fertilizer.

Effect of Seedlings Age and Nutrient Combinations on Growth and Yield of Proso Millet (Panicum miliaceum L.) in Lateritic Soils of Western Ghats

Background: Proso millet (Panicum miliaceum L.) was considered a self-pollinated annual crop that belongs to the family Poaceae. It was well adapted to many soil and climatic conditions. The productivity was low due to the use of poor quality seed, little or no use of fertilizers, traditional methods of cultivation, delay in nursery sowing and late transplanting. The Integrated Nutrient Supply System (INSS) approach involves the combined use of chemical fertilizers, organic manures and micronutrient fertilizers, which ensures higher crop productions and also helps to restore and sustain soil fertility. Therefore, the study was focused to manage the timely transplanting together with the suitable nutrient combination.Methods: A field experiment was conducted to study the “Effect of seedlings age and different nutrient combinations on growth and yield of Proso Millet (Panicum miliaceum L.) in lateritic soils of Western Ghats” during Kharif, 2016. The experiment was laid out in a split-plot design with four main plots and five subplot treatments. The main plot treatments composed of four ages of seedlings viz. 20, 30, 40 and 50 days. and five subplot treatments of nutrient combinations viz., 100% RDF, 75% RDF + 25% N through FYM, 50% RDF + 50% N through FYM, 25% RDF + 75% N through FYM and 100% N through FYM. Thus, there were twenty treatment combinations, replicated thrice.Result: Results revealed that the proso millet crop transplanted with 30 days old seedlings recorded significantly higher grain yield and straw yield over all other treatments. In nutrient combinations treatments, 100% RDF through chemical fertilizer recorded significantly higher mean plant height hill-1, number of functional leaves hill-1, number of functional tillers hill-1 and plant dry matter accumulation hill-1 than the other treatments and also produced significantly highest yields and yield attributing characters compared to the rest of the nutrient combinations.

Modelling climate smart rice-wheat production system in the middle Gangetic plains of India

A simulation study based on water balance approach and field experimentation with rice-wheat cropping system was carried out by employing daily rainfall and evaporation (2002–2016) and edaphic data of Experimental Farm of the university, Pusa (25.98°N, 85.67°E, 52 m amsl), Bihar, situated under middle Indo-Gangetic Plains. The aims of the study were to optimize transplanting dates and assess irrigation requirement and water productivity of rice with a view to achieve climate smart rice-wheat production system. The suitability of advancing wheat planting under this cropping system was also evaluated for escaping terminal heat stress during reproductive to maturity period. Under rice-wheat system, late transplanting of rice during kharif season (monsoon season, synonymously also called as wet season) and, consequently, late planting of wheat during rabi (winter) season tend to reduce grain yield significantly under a set of adverse environmental conditions during flowering to maturity phases of both the crops. The study revealed that rice crop of 150-day duration (seed to seed) could be successfully transplanted early in the kharif season during 20–30 June and be harvested by 25 October–5 November with the use of average 404–425-mm irrigation water to achieve potential yield and higher water productivity (1.648–1.731 kg m−3 ha−1). Early rice harvesting ensured early completion of wheat planting before 15 November, which helped in escaping terminal high-temperature stress during the reproductive phase. Hence, higher system productivity can be achieved by shifting the planting dates of rice and wheat through optimum utilization of natural resource environment (moisture and thermal regimes) and offsetting the negative impacts of erratic monsoon rains on rice growth and terminal heat stress and hailstorm on subsequent wheat crop.

Grain Yield and Agro-Climatic Indices of Rice Cultivars Transplanted in Different Dates in Mid-Western Tarai, Nepal

An experiment was conducted to assess the productivity and agro-climatic indices of different rice cultivars under staggered transplanting dates in farmers’ field at Lamahi, Dang during May to November 2018. The experiment was laid in a two factorial randomized complete block design with 9 treatments and 3 replications. Two factors included were: three rice cultivars; Arise-6444, Sarju-52, and Sukkha-3, and three transplanting dates; 19th June, 29th June, and 9th July. Phenological observation and yield attributing characters were recorded and statistical analysis was done. Cultivars under different transplanting dates showed significant variation in yield, yield attributes, and agro-climatic indices, individually and in interaction. Variety Arise-6444 attained early booting, panicle initiation, heading and flowering followed by Sukkha-3 and Sarju-52, respectively. Cultivar Arise-6444 showed the highest panicle weight (4.84g), effective tillers m-2 (242), grains panicle-1 (201) and grain yield (9213 kg ha-1). Early transplanting brought the phenological stages late as compared to mid and late transplanting. Cumulative GDD and PTI were significantly higher in Sarju-52 being 2066 and 15.90, respectively, whereas Arise-6444 showed the highest HUE (4.702). Irrespective of transplanting dates, early transplanting exhibited the highest GDD (2150.76) and PTI (16.36). Early transplanting of Sarju-52 showed the highest GDD (2211) while the highest PTI (16.59) was recorded in early transplanting of Arise-6444. Thus, varieties having high HUE should be planted early for better yield and to cope with the adverse effect of climate change.

Agricultural labor, COVID-19, and potential implications for food security and air quality in the breadbasket of India

To contain the COVID-19 pandemic, India imposed a national lockdown at the end of March 2020, a decision that resulted in a massive reverse migration as many workers across economic sectors returned to their home regions. Migrants provide the foundations of the agricultural workforce in the ‘breadbasket’ states of Punjab and Haryana in Northwest India.There are mounting concerns that near and potentially longer-term reductions in labor availability may jeopardize agricultural production and consequently national food security. The timing of rice transplanting at the beginning of the summer monsoon season has a cascading influence on productivity of the entire rice-wheat cropping system. To assess the potential for COVID-related reductions in the agriculture workforce to disrupt production of the dominant rice-wheat cropping pattern in these states, we use a spatial ex ante modelling framework to evaluate four scenarios representing a range of plausible labor constraints on the timing of rice transplanting. Averaged over both states, results suggest that rice productivity losses under all delay scenarios would be low as compare to those for wheat, with total system productivity loss estimates ranging from 9%, to 21%, equivalent to economic losses of USD $674 m to $1.48 billion. Late rice transplanting and harvesting can also aggravate winter air pollution with concomitant health risks. Technological options such as direct seeded rice, staggered nursery transplanting, and crop diversification away from rice can help address these challenges but require new approaches to policy and incentives for change.

Growth and yield descriptors of rice influenced by transplanting date

Boro rice faces two-way challenges – cold injury at different stages of growth due to early transplanting and early or pre-monsoon rain and flash flood for the late transplanting. An experiment was conducted to investigate the yield loss percentage of hybrid boro rice cultivars due to late transplanting. A two-factor experiment viz. two rice cultivars and three transplanting dates, was laid out in a randomized complete block design with three replications. All the studied morphological descriptors viz. plant height, number of tillers (total, effective and non-effective) and leaf size (length and width), and some of the yield and yield contributing descriptors viz. panicle length, length of primary branch, number and length of secondary branch, grain and straw yield and harvest index, were significantly influenced by both cultivars and transplanting times. Transplanting time had a little/insignificant effect on grain descriptors e.g., number panicle–1 , size (length, breadth and thickness), 1000-grain weight, etc. Although the cultivar Saru Madina produced longer panicle, higher number of primary and secondary branches panicle–1 and number of filled grains panicle–1 ; it also produced higher number of unfilled grain in primary and secondary branches (5 and 10 folds, respectively) compared to Ispahani-2. The maximum grain yield (7.81 t ha–1 ) was harvested from Ispahani-2 at 1st January transplanting and the lowest (6.29 t ha–1 ) from Saru Madina at 30th January transplanting. Boro rice cultivars should be transplanted on or before 15th January for grain yield maximization; the grain yield reduction reached up to 17% when transplanting operation done on 30th January.

Economic Viability of Wet Season Aromatic and Non-aromatic Rice Cultivation in Dinajpur District of Bangladesh

The aromatic rice has cultural and economic significance in Bangladesh. This study assessed the relative economic viability (profitability and risk) of aromatic and non-aromatic wet season (WS) rice varieties. The farm-level data for this study was collected through face to face interview from Dinajpur. An enterprise, partial and stochastic budget was developed in the study. Nearly half of the total T. Aman area in the case study villages was devoted to aromatic rice, in particular modern aromatic cultivar BRRI dhan34, mainly due to it gave notable extra benefits over local aromatic (BDT. 13,519/ha) and non-aromatic (BDT. 20,197/ha) cultivars. There was no significant difference in yield between BRRI dhan34 and local aromatic variety, namely Kataribhog. However, BRRI dhan34 was found to be the more economically viable (gave higher returns and posed less risks) option due to its higher and stable market price. The higher price, guaranteed market demand, lower fertilizer requirements, shorter growth duration and suitability of late transplanting of BRRI dhan34 are the major drivers behind its widespread popularity in the region. It was clear from this research that farmers in the case study villages are highly motivated to increase adoption of the aromatic cultivar due to its price advantage and ensured market. Therefore, the development and dissemination of the higher yield potential biotic stress tolerant aromatic variety should get priority in policy planning for higher income generation and export earnings for the country.

EFFECT OF PLANTING DATE AND FOLIAR FEEDING ON PRODUCTIVITY AND FRUIT QUALITY OF EGGPLANT

A factorial experiment (2 transplanting dates X 3 foliar feeding levels) in split plot design was conducted at Gemmeiza Agric. Res. Station, Gharbeya Governorate, Egypt during 2016 and 2017 growing summer seasons aiming to evaluate effects of transplanting date and foliar feeding with NPK and their interactions on growth, productivity and fruit quality of eggplant (Solanum melongena L,) c.v. Black Beauty. The two tested transplanting dates were summer transplanting on April and late summer on June. While, the three examined foliar feeding levels were spraying with tap water as control, spraying with Potassium-F fertilizer at rate of 3 ml/L or with Raizante fertilizer at rate of 2 ml/L. Foliar spray was done three times throughout growing season. Summer transplanting (April) significantly increased plant height, branches and leaves numbers/ plant and leaf area. Also, leaf percentages of N, P and K as well as total chlorophyll content were increased in April transplanting. Finally, total fruit yield (Ton/ fed) and its quality, expressed as more contents of total soluble solids (%) and total sugars (g/ 100 g D.W.) and less contents of total phenols (mg/ g D.W.) and acidity (%) in fruit tissues, were significantly increased in April transplanting comparing to late summer transplanting (June). Foliar spraying with Potassium-F at 3 ml/L or Raizante at 2 ml/L significantly increased all the above mentioned growth traits and leaf chemical constituents and in turn resulted significant increases in total fruit yield/ fed comparing to unfertilized control plants. Also, spraying Potassium–F or Raizante significantly reduced fruit firmness (kg/ cm2) and fruit contents of total phenols and titratable acidity, at the same time significantly increased total soluble solids, total sugars and K (%) in fruit tissues. Raizante spray was more effective than Potassium-F in enhancing plant growth and fruit yield and its quality. Conclusively: when transplanting date interacted with foliar feeding, different significant responses were found. In general, interaction treatment of summer transplanting (April transplanting date) X foliar feeding with Raizante at 2 ml/L significantly increased plant growth traits and leaf contents of N, P, K and chlorophylls. Such interaction treatment resulted in the highest total fruit yield/ fed with the highest quality (high total soluble solids and total sugars and less total phenols and acidity in fruits) comparing all other interaction treatments.

Potential yields, yield gaps, and optimal agronomic management practices for rice production systems in different regions of China

Understanding crop potential yields, yield gaps, and optimal agronomic management practices helps in identifying the limiting factors, scope, and ways to achieve sustainable intensified agricultural production. Here, using detailed field trial data collected from 1981 to 2009 at 11 agro-meteorological experimental stations and the crop model CERES–Rice, we investigated changes in potential yields, water- and nitrogen-stressed yields, and yield gaps of rice in the major rice cultivation regions of China during the collection period. We further identified the optimal nitrogen application rate, transplanting date, and cultivar traits for the sustainable intensification of rice production systems in different regions. Owing to climate change, the potential rice yields declined or changed little in the Middle and Lower Reaches of the Yangtze River (MLRYR), while they increased or changed little in the Northeastern China Plain (NECP) during 1981–2009. Rice yield gaps shrank in the major rice production regions because the actual yields increased and approached the potential yields. The average yield gap was 16.0% in the 2000s, with water and nitrogen stresses being the limiting factors in the NECP and water stress being the major limiting factor in the MLRYR. The nitrogen application rate was suggested to be increased by 47.5% and 21.7% for single rice (i.e., rice cultivated in a single season per year) in the NECP and MLRYR, respectively, and increased by 5.2% for early rice (i.e., rice cultivated in the early season in a rice–rice rotation system per year). However, it was suggested to be reduced by 13.1% for late rice (i.e., rice cultivated in the late season in a rice–rice rotation system per year). Early transplanting could increase the yield, while late transplanting could decrease the yield. The impacts were greater for single rice in the NECP and late rice in the MLRYR than for single rice and early rice in the MLRYR. Cultivars with longer growth durations, and greater spikelet numbers and grain weights, could significantly increase the rice yield by 14.8%–45.6%. The optimal cultivars, combined with advancing transplanting by 10 d, could increase rice yields by 29.2%–68.9%. Our findings provide new approaches, important insights, and effective options for the sustainable intensification of rice production systems in different regions of China.

Effect of Transplanting Zones and Dates on Pre-imaginal Populations, Parasitism and Attacks of Major Insect Pests of Rice on the Rice-Growing Area of la Vallée du Kou (Bobo-Dioulasso)

Lepidopterous stem borers cause extensive damage in irrigated rice in Burkina Faso and regularly compromise the harvest of the dry season rice in the rice-growing area of la Vallee du Kou in western Burkina Faso. Yield of losses of 40% were observe during the dry season. The study conducted during the wet season in 2015 examined the effects of areas and of transplanting dates on the evolution of population of stem borer's damage and of parasitism. Rice irrigation area of la Vallee du Kou was divided into three areas within which 12 farmers were selected on the basis of three dates of transplanting rice; they were total 36 for the days three transplanting dates. According to agronomic evaluation, the transplantation dates are influence by the number of tillers and by the number of panicles. The maximum average number of tillers was observed in the second area within the first date of transplantation. Otherwise the second area and the second date recorded the highest number of panicles. Entomological observations were carried on every 7 days from the 21th day to 91th day after rice transplanting in each of the 36 fields. Late transplanting (August) are the most exposed to Orseolia oryzivora attacks. The genus Chilo spp, Maliarpha and Diopsis spp were the most important pests in rice plants on the perimeter of la Vallee du Kou. Periods of greatest damage were observed in tillering. They were responsible for the deadhearts damage, for white panicles and for the highest rates. These damages were recorded during the first date of rice transplanting. Parasitism associated with the genus Chilo was observed in the first transplanting date. The hectare average yields were most important in the second transplanting date of within the third area. These results on the pre-imaginal populations are important data. These data can be taken into account to improve the development of a strategy to fight against the major insect pests of rice plants. All these elements are linked to the climatic variations.

Evaluating the Optimum Transplanting Time for Different Coarse Rice Genotypes under Semi-Arid Conditions of Faisalabad

Continuously changing climate and availability of different rice genotypes make it necessary to find optimum time of sowing as well as suitable variety for cultivation to get maximum productivity under a specific set of climatic conditions. A field study was carried out to search out the suitable rice transplanting time for four different coarse genotypes under the semi-arid environment of Faisalabad. The experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad and was laid out in randomized complete block design (RCBD) with split plot arrangement keeping transplanting time in main plots while rice genotypes in subplots. Variability among treatments was measured by Fisher’s ANOVA (P ≤ 5%) and LSD test was applied to compare the differences among treatments’ means. The ANOVA indicated statistically significant differences among genotypes as well as transplanting dates irrespective of all studied traits while interactive effects of both were found to be non-significant. NIBGE-1 performed best with maximum paddy yield of 6.05 t/ha while KSK-434 performed poor with paddy yield of 2.78 t/ha. Increased paddy yield and yield related parameters of all rice genotypes were recorded where transplantation was done on 25th of June. Generally, paddy yield decreased with delaying the transplanting time. The results suggested that NIBGE-1 can perform better under the semi-arid conditions of Faisalabad and last week of June might be the optimum time for nursery transplantation. It can also be further elucidated that late transplanting causes yield reduction which could not be recommended among farmers.

東北地域における水稲品種の晩植適性

東北地域における水稲品種の晩植適性

The Impacts of Climate Change and Adaptation Measures for Rice Production in Central Vietnam: A Pilot in Nui Thanh District, Quang Nam Province

Abstract: This study analyses the impacts of climate change on rice production and adaptation in Nui Thanh district, Quang Nam province. This study pursues to seek following queries including forecast future rainfall, temperature, rice yield, and analyze adaptation measures to improve rice production under different climate change scenarios in Nui Thanh district, Quang Nam province, Vietnam. The study was based on firstly identification of the problem in the study area followed by collection of secondary data on weather, soil characteristics and crop management. Then the downscaling model was used to predict the temperature and precipitation of the study area in the future by A2 and B2 scenarios. The Aquacrop model was used to simulate the yield response. After that, the impact of climate change scenarios on rice yield was analyzed. Lastly, the evaluation for adaptation measure to improve rice production under climate change based on water management was determined. Results show that climate change will reduce rice yield from 1.29 to 23.05% during the winter season for both scenarios and all time periods, whereas an increase in yield by 2.07 to 6.66% is expected in the summer season for the 2020s and 2050s; relative to baseline yield. The overall decrease of rice yield in the winter season can be offset, and rice yield in the summer season can be enhanced to potential levels by altering the transplanting dates and by introducing supplementary irrigation. Late transplanting of rice shows an increase of yield by 20-27% in future. Whereas supplementary irrigation of rice in the winter season shows an increase in yield of up to 42% in future. Increasing the fertilizer application rate enhances the yield from 0.3 to 29.8% under future climates. Similarly, changing the number of doses of fertilizer application increased rice yield by 1.8 to 5.1%, relative to the current practice of single dose application. Shifting to other heat tolerant varieties also increased the rice production.

Crop and varietal diversification of rainfed rice based cropping systems for higher productivity and profitability in Eastern India.

Rice-rice system and rice fallows are no longer productive in Southeast Asia. Crop and varietal diversification of the rice based cropping systems may improve the productivity and profitability of the systems. Diversification is also a viable option to mitigate the risk of climate change. In Eastern India, farmers cultivate rice during rainy season (June–September) and land leftovers fallow after rice harvest in the post-rainy season (November–May) due to lack of sufficient rainfall or irrigation amenities. However, in lowland areas, sufficient residual soil moistures are available in rice fallow in the post-rainy season (November–March), which can be utilized for raising second crops in the region. Implementation of suitable crop/varietal diversification is thus very much vital to achieve this objective. To assess the yield performance of rice varieties under timely and late sown conditions and to evaluate the performance of dry season crops following them, three different duration rice cultivars were transplanted in July and August. In dry season several non-rice crops were sown in rice fallow to constitute a cropping system. The results revealed that tiller occurrence, biomass accumulation, dry matter remobilization, crop growth rate, and ultimately yield were significantly decreased under late transplanting. On an average, around 30% yield reduction obtained under late sowing may be due to low temperature stress and high rainfall at reproductive stages of the crop. Dry season crops following short duration rice cultivars performed better in terms of grain yield. In the dry season, toria was profitable when sown earlier and if sowing was delayed greengram was suitable. Highest system productivity and profitability under timely sown rice may be due to higher dry matter remobilization from source to sink. A significant correlation was observed between biomass production and grain yield. We infer that late transplanting decrease the tiller occurrence and assimilate remobilization efficiency, which may be responsible for the reduced grain yield.

Effect of transplanting times on pollen and spikelet sterility, growth and yield of aman rice

A field experiment was conducted to study the effect of planting dates on pollen/spikelet sterility, grain development and yield of hybrid rice in T. Aman season. The two varieties: Heera-4 (hybrid) and BINAdhan-7 (inbred) were transplanted on five consecutive dates at fifteen days interval viz. 15 July, 30 July, 15 August, 30 August and 15 September of 2011. The effect of variety and transplanting date showed significant variation in pollen sterility, grain growth &amp; development, panicle length, filled grains panicle-1, spikelet sterility and grain yield. Pollen sterility was the highest in Heera-4 (&gt;80%) consequently spikelet sterility for transplanting on 15 July while transplanting on 30 July low pollen sterility consequently spikelet sterility. Both early or late transplanting affected grain growth and development, enhanced pollen sterility as well as spikelet sterility and reduced grain yield. Late transplanting (30 August and 15 September) significantly reduced panicle length and filled grains panicle-1. Transplanting on 30 July gave low pollen sterility as well as spikelet sterility, high panicle length and high filled grains panicle-1 consequently greater grain yield in the varieties.Progressive Agriculture 27 (4): 400-408, 2016