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A better understanding of rainfall variability and trends is vital for agricultural production systems which are largely dependent on climate. This study aims to analyze and to quantify the significance of change on annual, seasonal and daily rainfall in North and Central Benin, and to infer future challenges for crop production. Daily rainfall data for the 1970–2016 period measured at three weather stations (Savè, Malanville and Tanguiéta) were obtained from the Benin National Weather Agency. Descriptive statistics, standardized anomaly of rainfall (SAR) and rainfall intensity were used to analyze rainfall variability. For rainfall trends analysis, we tested for auto-correlation and used the Mann–Kendall and modified Mann–Kendall tests for non-auto-correlated and auto-correlated data, respectively. Trend magnitude was estimated using Sen's slope. Globally, a moderate-to-high seasonal rainfall and low variability of yearly rainfall were observed. The SAR indicated more than 50% of the years in the studies period experienced dry years. Between 1970 and 2016, a significant 20% increase was observed in the yearly rainfall in Tanguiéta, whereas no significant trends were observed in Malanville (10% increase) and Savè (0.6% decrease). The general rainfall increase observed during the post-monsoon season (October–November) in the three weather stations potentially increases flood frequencies during the harvest period of some crops, which can reduce crop yields. Adaptation strategies are needed which can mitigate the effects of climate change on agriculture. These findings are essential to the climate risk management in agriculture and to target appropriate adaptive measures for resilience building in the sector. [ABSTRACT FROM AUTHOR]

Food cost and seasonal availability are important determinants of food choice and ultimately nutrient intake. This study aimed at establishing the nutritional composition of least-cost staple food sources of nutrients in Kamuli, Buyende and Pallisa districts in eastern Uganda across the cropping seasons. The World Food Programme (WFP) Vulnerability Analysis and Mapping (VAM) Market Analysis Tool guidelines were used to conduct a mini-survey to determine seasonal prices and availability of foods. Retailers (n= 268) from six markets in Kamuli, three in Buyende and six in Pallisa were interviewed. The least-cost sources of energy, protein, iron and zinc were determined using nutrient-cost values. The nutrient composition of the least-cost foods were determined using standard methods. For the first dry season, the least cost sources of energy, protein, iron and zinc were maize (0.052 $/1000kcal), soybeans (0.016 $/10g), maize (0.070 $/10mg) and maize (0.086 $/10mg), respectively. For the second dry season, the least cost sources of energy, protein, iron and zinc were maize (0.052 $/1000kcal), soybeans (0.015 $/10g), maize (0.070 $/10mg) and maize (0.086 $/10mg). For the first rainy season, the least cost source of energy was sorghum (0.074 $/1000kcal), protein was groundnuts (0.019 $/10g), iron was sesame (0.100 $/10mg) and zinc was sweet potatoes (0.123 $/10mg), respectively. For the second rainy season, the least cost sources of energy, protein, iron and zinc were sorghum (0.049 $/1000kcal), groundnuts (0.016 $/10g), sesame (0.067 $/10mg) and sweet potatoes (0.082 $/10mg), respectively. The richest sources of energy, sugars and starch, protein, fat, fibre and iron were sesame (797.2 ± 116.84 Kcal/100g), sweet potatoes (11.5 ± 1.22 and 86.8 ± 10.75 g/100g), soybeans (40.7 ± 4.58 g/100g), sesame (52.9 ± 3.82 g/100g), soybeans (7.0 ± 0.32 g/100g), groundnuts (7.0 ± 0.82 mg/g). The nutrition composition of least-cost foods in the dry seasons and rainy seasons indicates that they can be used to formulate low-cost nutrient-dense mixtures for the respective seasons. [ABSTRACT FROM AUTHOR]

Purpose: The increasing demand for livestock products is the main driver of expansion of maize cultivation areas in Thailand. However, its environmental impacts, especially those associated with greenhouse gas (GHG) emissions in different cropping seasons, remain unclear. Therefore, this study aimed to estimate the carbon dioxide equivalences (CO2-eq) occurring during various weather seasons (early rainy, late rainy, and dry seasons) of maize production. Life cycle costing (LCC) associated with grain production were also evaluated. Methods: A total of 131 plantation land plots in dominant areas of maize plantation in Chiang Rai, Nan, Tak, Phetchabun, and Loei Provinces were selected for data collection. The system boundaries included the cultivation, grain drying, and transportation of grain to feed mills. A carbon movement categorization method was employed to determine CO2 equivalences including carbon emissions, fixation, and reduction. The functional unit used for CO2 equivalences evaluation was either kg CO2-eq/ha or kg CO2-eq/ton grain. LCC was used as analytical tool to examine the total cost and net profit of maize production among different cropping seasons. Results and discussion: Total GHG emissions from maize production were found to be an average of 429 ± 27 kg CO2-eq/ton grain. The highest emissions among different seasons of maize production were during the dry season which were 2970 ± 792 kg CO2-eq/ha. However, no significant difference was observed between total emissions per unit of grain produced in the different seasons. The results of LCC of maize grain production revealed that the net economic benefits per carbon emitted during the early rainy, late rainy, and dry seasons were 0.44, 0.49, and 0.50 USD/kg CO2-eq, respectively. These confirmed that the dry season exhibited greater economic benefits compared with rainy seasons. Moreover, the carbon fixation efficiency was computed to be 79.0–80.2%, indicating that maize production still emits carbon to the atmosphere. Conclusions and recommendations: This study evaluated CO2 emissions from different cropping seasons of maize production to identify the most suitable cropping season in terms of lower CO2 emissions and higher net economic benefit. These findings may be used to effect better government policy on reducing GHG emissions and managing land use for maize cultivation in Thailand. [ABSTRACT FROM AUTHOR]

This study aimed at determining how different rates of poultry manure affected the growth and production of onions (Allium cepa L.) in wet and dry seasons. The experiment was conducted from July to October 2019 and from January to April 2020 at the Department of Crop Science teaching and research farm, University of Nigeria Nsukka, South Eastern Nigeria. The experiment applied a randomized complete block design with nine replications spread over three blocks. The treatments were four doses of poultry manure (0, 10, 20 and 30 t.ha-1) tried in two seasons (wet and dry season). Prior to the investigations, soil analysis of the experimental site and poultry manure nutrient content were carried out. The growth pattern and yield was higher during the wet season. Poultry manure at amount of 30 t.ha-1 gave the best growth attributes (number of leaves, leaf length, and leaf diameter) 14.22, 53.67 cm and 0.88 cm respectively while the 20 t.ha-1 had the highest plant height and bulb fresh weight, 60.86 cm and 2 kg/plant respectively. The trend was not the same as in dry season planting because 20 t.ha-1 poultry manure differs significantly from other rates of poultry manure considered. Plant height, leaf length, leaf diameter and bulb fresh weight (57.64 cm, 55.28 cm, 0.84 cm and 0.63 kg/plant respectively) were statistically significantly (p < 0.05) different at 5% probability level. Utilization of 20 t.ha-1 of poultry manure and planting in wet season gave the best growth and yield of onion vegetable.

This study aimed at determining how different rates of poultry manure affected the growth and production of onions (Allium cepa L.) in wet and dry seasons. The experiment had been conducted from July to October 2019 and from January to April 2020 at the Department of Crop Science teaching and research farm, University of Nigeria Nsukka, South Eastern Nigeria. The experiment applied a randomized complete block design with nine replications spread over three blocks. The treatments were four doses of poultry manure (0, 10, 20 and 30 t.ha-1) tried in two seasons (wet and dry season). Prior to the investigations, soil analysis of the experimental site and poultry manure nutrient content were carried out. The growth pattern and yield was higher during the wet season. Poultry manure at amount of 30 t.ha-1 gave the best growth attributes (number of leaves, leaf length, and leaf diameter) 14.22, 53.67 cm and 0.88 cm respectively while the 20 t.ha-1 had the highest plant height and bulb fresh weight, 60.86 cm and 2 kg/plant respectively. The trend was not the same as in dry season planting because 20 t.ha-1 poultry manure differs significantly from other rates of poultry manure considered. Plant height, leaf length, leaf diameter and bulb fresh weight (57.64 cm, 55.28 cm, 0.84 cm and 0.63 kg/plant respectively) were statistically significantly (p < 0.05) different at 5% probability level. Utilization of 20 t.ha-1 of poultry manure and planing in wet season gave the best growth and yield of onion vegetable. [ABSTRACT FROM AUTHOR]

The current manuscript presents the spatial analysis of the temperature trends during India's Rabi and Kharif cropping seasons. We investigated the district-level temperature trends from 1966 to 2015 using Climate Research Unit data. All the 666 Indian districts showed significant upward temperature trends for the Rabi season. This upward trend was contributed by a significant rise in monthly temperatures during November (645 districts), December (664 districts), February (659 districts), and March (626 districts). January had the minimum number of Indian districts with a significant upward temperature trend during the Rabi season (322 districts). For the Kharif season, 640 Indian districts showed significant upward temperature trends. Significant rise in monthly temperatures during August (622 districts), September (595 districts), and October (627 districts) contributed to this upward trend. June (296 districts) and July (411 districts) had fewer districts with significant upward temperature trends. The results reflect a severe challenge of rising temperatures during India's cropping seasons. [ABSTRACT FROM AUTHOR]

Taro is the world's fourth most important root crop in terms of production by weight, behind cassava, potato, and sweet potato, and the second most significant staple root crop in terms of consumption, after sweet potato. However, a shortage of well-adapted cultivars is one of the production problems that contribute to low yields and small planted areas across the country. As a result, genotypes with high production potential and adaptability for local environmental circumstances must be evaluated. During the 2018 and 2019 main cropping seasons, field experiments were done in the North-Bench woreda in the Bench-Sheko zone, south-western Ethiopia, to improve taro production and productivity by evaluating and selecting high yielding taro cultivars. Three improved and one local taro variety were used in the trial, which was laid out in a randomized complete block design (RCBD) with three replications at the North bench location. The data were collected and analyzed by using SAS 9.2 Version statistical software. The study's findings revealed that variety had a significant (P < 0.01) impact on all of the variables considered. Accordingly, combined analysis over years indicated that the highest leaf number per plant (7.76), plant diameter (40.82cm), corm diameter (8.28cm), cormel number per plant (6.10), and total yield (22.34 t/ha) were observed for Boloso-1 variety. The highest value of the number of suckers per plant was also observed for the Boloso-1 variety in both years (8.2 in 2018 and 6.2 in the 2019 growing season). However, combined analysis over years indicated the highest corm length in local variety (12.15cm) followed by Boloso-1 variety (10.34cm). Therefore, based on the overall results of this study, the Boloso-1 variety performed best and was more adapted to the area as compared to other varieties. This variety should be popularized and disseminated to users to boost the production and productivity of taro in the testing location and similar agro-ecologies of the region.

This research was conducted on a farm of Payam-e-Noor University in Piranshahr, in West Azerbaijan province of Iran, during 2014-2015 and 2015-2016 crop sessions to investigate the wheat physiological traits response to standard and ecological agricultural systems. The experiment was conducted as a split-plot design with two factors and three replications. The first factor, which was considered the main plot, included high, low-input, and ecological agricultural systems. Subplots were seed pre-treatment, including control (without priming), hydro priming, and food priming with ascorbate. The results showed that the least photosynthesis rate and mesophilic conductance were related to lowinput agricultural system; however, in the ecological system, the transpiration, substomatal carbon dioxide, and water use efficiency of photosynthesis were the lowest. Also, seed priming increased the photosynthesis rate, mesophilic conductivity, and water use efficiency of photosynthesis. [ABSTRACT FROM AUTHOR]

Field experiments were carried out during the 2015/16 and 2016/17 dry cropping seasons at the Experiment Farm of the Faculty of Agriculture, University of Benin, Benin City. The study was a 2 x 4 factorial fitted into a randomized complete block design (RCBD) in three replications. Two tomato varieties (Roma savannah and UC82) and four times of fertilizer application (T1: all fertilizer applied at 2 weeks after transplanting (2WAT), T2: 1/2 of the fertilizer applied at 2WAT and 1/2 at flowering, T3: one third 1/3 applied at 2WAT, 1/3 at flowering, 1/3 at fruiting and T4: all fertilizer applied at flowering) were used. In both years, stem diameter, number of flowers, fruits and fruit weight/plant (kg/ha) and yield were significantly improved by Roma savannah. Fruit diameter (5.70 cm and 4.75 cm) increased with UC82 compared with Roma savannah which produced the lowest fruit diameter (3.95 cm and 3.11 cm). Roma savannah had a higher fruit yield of 8.59 t ha-1 and 7.24 t ha-1 compared with 5.99 t ha-1 and 4.57 t ha-1 produced by UC82. In 2016/17 cropping season T3 and T4 significantly improved stem diameter above other treatments and T2 and T4 produced highest fruit yields which were similar. However, in both years highest fruit yields (10.39 t ha-1 and 7.09 t ha-1) were consistent with T2. The use of Roman savannah variety and T2 treatment should be encouraged for tomato production, in terms of higher fruit yield in this locality. [ABSTRACT FROM AUTHOR]

• New mapping framework for flood and salinity risks in rice production of deltas. • Maps on a) peak risk, b) time-sequenced risk, c) sustained risk, d) risk profiles. • Sustained flood risk in Mekong Delta affects 39% of total rice area. • Sustained salinity risk affects 44% of total rice area incl. 31% for > three months. • Different methods have pros and cons, but add up to comprehensive risk assessment. The rationale for mapping hydrological risks in the Mekong River Delta (MRD) is the large extent of flood-affected and salinity-affected areas that severely constrain rice production. This new study on risk mapping expands previous approaches in depth (resolutions of 300 × 300 m and 1 h) and width (combining different types of maps). Data obtained with a hydrological model have been evaluated through four different methods of mapping individual attributes of risks that collectively comprise a comprehensive risk assessment for rice production: 1) Peak risk maps: These maps show the maximum water heights in a high-water year and maximum salinity concentrations in a low-water year. 2) Time-sequenced risk maps: The article provides hyperlinks to videos that encompass time-sequenced maps for the critical periods of floods (July-December in daily intervals) and salinity (March-April in hourly intervals) for all provinces. 3) Sustained risk maps (for rice): This approach is based on clearly defined thresholds of flood and salinity risks considering the duration of risk exposure at a given location. We have set thresholds for water heights exceeding 0.4 m and salinity concentrations above 2 g/l for 7 consecutive days to define start and end dates of sustained risks for rice. 4) Risk profile maps (for rice): The data on sustained risk have been aggregated at province level to calculate the geographic coverage of risk areas as compared with the total rice area. The rice area exposed to sustained flood risks in the MRD comprises 39% of the total rice area, which can be further subdivided into 24% with long (>three months), 12% with moderate (1–3 months), and 3% with short (1–4 weeks) risk duration. Likewise, the salinity-prone rice area accounts for 44% of the total rice area and can be subdivided into 31% with long, 8% with medium, and 5% with short risk duration. Finally, we have discussed the pros and cons of these different risk mapping methods in view of required adaptation strategies for rice production to cope with rapidly changing environmental conditions. [ABSTRACT FROM AUTHOR]

Shading nets have been increasingly drawing research interest, as they allow us to improve the environmental conditions for greenhouse-grown crops. The effects of two shading nets (50% and 79% shading degree), plus an unshaded control, on yield, mineral composition and antioxidants of perennial wall rocket (Diplotaxis tenuifolia L.-D.C.) grown under tunnels in southern Italy were determined. The shading application resulted in a yield decrease, compared to the unshaded control, except for the highest production under 50% shading in July. The highest yield was recorded in the April–May and May–June and the lowest in July. Similar trends were recorded for plant dry weight, leaf number per rosette and mean weight, but the latter showed the highest value under 79% light extinction in July. The rocket leaves were brighter in the summer cycles than in the spring ones. Leaf nitrate was highest in spring and under 79% shading. Potassium, phosphorus, calcium and magnesium showed the highest values in spring and in the unshaded control. The lipophilic antioxidant activity showed the highest values under the 79% shading net in the spring cropping seasons, whereas in July it did not significantly differ from 50% light extinction. The hydrophilic antioxidant activity always attained the highest values in the unshaded control. The unshaded leaves had the highest total phenol accumulation when grown in April–May and the lowest in July. The total ascorbic acid content was always highest in the unshaded control leaves compared to the shading treatments. Fifty percent crop shading is, therefore, an effective sustainable tool for increasing the yield of perennial wall rocket leaves in July, when the light intensity under the plastic tunnel exceeds the plant requirements, also resulting in a mineral composition that is not significantly different from that of the unshaded crops.

Monitoring and detecting trends of climatic variables like rainfall and temperature are essential for agricultural developments in the context of climate change. The present study has detected trends in annual and cropping seasonal rainfall and temperature data for the period of 1961-2011 using Mann-Kendall (MK) test, Spearman's rho (SR) test and modified Mann-Kendall test that has been applied to the significant lag-1 serial correlated time series data, and slope has been estimated using Sen's Slope estimator for twelve meteorological stations located in the western part of Bangladesh covering about 41 % of the country. Almost 71 % trends explored by MK test in annual rainfall are statistically insignificant, and SR test also complies it. The spatial distribution of rainfall trend shows insignificant positive trends in major part of the area. Significant positive trends both by MK test and by SR test at 95 % confidence levels are observed at rates of 8.56, 11.15 and 13.66 mm/year at Dinajpur, Rangpur and Khepupara stations, respectively, and the Kharif season rainfall of these stations also shows significant increasing trends except Dinajpur. On the other hand, significant decreasing trends in annual rainfall are found at Bhola (−11.67 mm/year) and Rajshahi (−5.951 mm/year) stations and decreasing trends in rainfall dominated the Pre- Kharif season over the area. But, 83.33 % of the stations show rising trends in annual mean temperature with significant positive trends (as observed by both MK test and SR test) at Rangpur, Bogra, Faridpur, Jessore and Bhola stations where the rate of changes vary from 0.013 °C/year at Faridpur to 0.08 °C/year at Bhola. Most of the trends in Rabi and Pre- Kharif seasons of mean temperatures are not statistically significant. However, all stations except Barisal show significant rising trends in temperature in Kharif season. To cope with this changing pattern of rainfall and temperature, effective adaptation strategies should be taken to keep up the agricultural production that is related to livelihood of the most people and to ensure the country's food security. [ABSTRACT FROM AUTHOR]

O feijoeiro é uma das principais culturas do país, e o Estado de Minas Gerais é um dos maiores produtores, representando cerca de 15% da produção nacional. O objetivo deste trabalho foi testar o desempenho de linhagens de feijoeiro comum cultivadas nas épocas daságuas e do inverno, na região do Triângulo Mineiro, Minas Gerais. No cultivo das águas (semeadura em dezembro de 2005) e do inverno (semeadura em maio de 2006), as linhagens/cultivares testadas foram BRS Horizonte, CNFC 8059, CNFC 8065, CNFC 8075, VC-6, VC-7, VC-8, VC-9, VC-10, VC-11, VC-12, CNFC 10443, CNFC 10453, CNFC 10476,MA-I-2.5, MA-I-8.9, MA-I-18.13, RC-I-8, CV-46, CV-55 e Z-22, além das testemunhas BRSMG Majestoso, Pérola e BRSMG Talismã e VC-3. Em cada experimento, o delineamento experimental foi o de blocos casualizados com 25 tratamentos, em três repetições, a parcela útil foi de 4 m2. No cultivo das águas, os rendimentos das linhagens mais produtivas variaram entre 2,69 e 2,78 t ha-1 (VC-9 e VC-10, respectivamente) e, no inverno, alcançaram 3 t ha-1 (3,01 e 3,00 t ha-1, CNFC 8065 e Z-22, respectivamente). De maneira geral, as linhagens foram maisprodutivas no cultivo do inverno, embora a interação entre linhagens e época de cultivo tenha indicado desempenho distinto entre elas em relação à época.The common bean is one of the most important crops in Brazil, and Minas Gerais state is one of its largest producers, representing about 15% of the national production. The aim of this studywas to evaluate the performance of common bean lineages cultivated during the rainy and winter seasons in the Triângulo Mineiro region, Minas Gerais state, Brazil. In the rainy growing season (sowing in December, 2005) and in the winter season (sowing in May, 2006), the tested lineages were BRS Horizonte, CNFC 8059, CNFC 8065, CNFC 8075, VC-6, VC-7, VC-8, VC-9, VC- 10, VC-11, VC-12, CNFC 10443, CNFC 10453, CNFC 10476, MA-I-2.5, MA-I-8.9, MA-I- 18.13, RC-I-8, CV-46, CV-55 and Z-22, in addition to the controls OP-NS-331 (BRSMG Majestoso), Pérola and BRSMG Talismã and VC-3. In each experiment, a randomized blockdesign was set up with 25 treatments and three replications with a useful experimental plot of 4 m2. In the rainy growing season, the yield potential of the most productive lineages varied between 2.69 and 2.78 t ha-1 (VC-9 and VC-10, respectively), and in the winter season achieved 3 t ha-1 (3.01 and 3.00 t ha-1, CNFC 8065 and Z-22, respectively). In general, the lineages were more productive in the winter season though their interaction with the growing seasonsindicated distinct performance between them according to season.

The study was conducted to investigate the impacts of fertilizer application on soil properties in Kaharole upazila of Dinajpur district in Bangladesh. Samples were collected to analyze the variation of soil nutrients in three cropping seasons: season-1 (March-April, 2013), season-2 (August-September, 2013) and season-3 (January-February, 2014). In each season 10 samples, 6 from conventionally cultivated soil (CCS) and 4 from organic fertilized soil (OFS), were collected from 10 randomly selected sampling points. The study observed acidic soil pH in all three cropping seasons, while soil pH was decreasing gradually with fertilizer application. The results of the study clearly depicted that all the soil nutrient contents and OM decreased with the application of fertilizers in different cropping seasons except Zn and Fe. The OFS contains relatively higher amount of OM and essential nutrients than CCS except Fe and Zn. The study shows that the continuous application of fertilizer in agricultural lands reduces soil fertility evolving nutrient deficiency in the soil; resulting in reduced crop productivity. [ABSTRACT FROM AUTHOR]

Droughts are usually destructive when they coincide with crop growing season. Cross-seasonal drought characterization can better inform drought mitigation efforts. The present study relies on precipitation data from the Global Precipitation Climatology Centre to reconstruct historical droughts during different climatic seasons in Balochistan province, Pakistan. We identified seasonal drought events based on the standardized precipitation index for each season. The distribution of reconstructed drought events was analyzed to determine their seasonality and to calculate their return periods. Using these return periods, we constructed seasonal drought maps. The study revealed that early winter droughts are frequent in the north of Balochistan, where the return periods of moderate, severe, and extreme droughts are 7, 21, and 55 years, respectively. Severe and extreme late winter droughts are more frequent in the upper north, with return periods of 16 and 35 years, respectively. Early summer droughts occur more frequently in the east, returning every 8, 20, and 60 years; late summer droughts occur in the northeast, with moderate, severe, and extreme droughts returning every 8, 22, and 65 years, respectively. Rabi droughts are more frequently in the central and northeaster regions of Balochistan, while more severe kharif droughts occur primarily in the eastern regions. These seasonal droughts were found to be positively correlated with variations in the seasonal rainfall throughout the study area. The findings of this study contribute to our understanding of seasonal drought characteristics and help to inform drought mitigation planning. [ABSTRACT FROM AUTHOR]

Contribution on Wheat Culture Development in South-Kivu, Democratic Republic of Congo.Yield-performance of Two Genotypes, from Burundi, in Various Local Agroecological Zones. In four sites (Lemera, Bugobe, Mulungu & Cifunzi), two genotypes (Romany & Kenya Nyangumi) were evaluated in contrasting agroecological conditions for their yield adaptibility, during two cropping seasons, from 1998 to 1999. Multilocational trials were set up, in different sites, following a split-plot experimental design, with repeated measurements during two cropping seasons. Genotypes were the main plots and the manures, the subplots. The subplots were randomized with main plots and replicated four times. Differences between environments, genotypes and cropping seasons were significant for the grain yield. The effects of genotypes by environment (G X E) interaction, for grain yield was significant. The general mean yield obtained when genotypes are combined or not with organic fertilizers is of 1.46 t/ha. The best yields were recorded at Mulungu (1.83 t/ha) and Lemera (1.61 t/ha) sites with Kenya Nyangumi genotype. The high yields were recorded at Bugobe (1.51 t/ha) and Lemera (1.88 t/ha) sites with Romany genotype. The application of organic fertilizers increase the yield of genotypes up to 10- 36%.

Drought is one of the most frequent natural disasters in Bangladesh which severely affect agro-based economy and people's livelihood in almost every year. Characterization of droughts in a systematic way is therefore critical in order to take necessary actions toward drought mitigation and sustainable development. In this study, standardized precipitation index is used to understand the spatial distribution of meteorological droughts during various climatic seasons such as premonsoon, monsoon, and winter seasons as well as cropping seasons such as Pre-Kharif (March-May), Kharif (May-October), and Rabi (December-February). Rainfall data collected from 29 rainfall gauge stations located in different parts of the country were used for a period of 50 years (1961-2010). The study reveals that the spatial characteristics of droughts vary widely according to season. Premonsoon droughts are more frequent in the northwest, monsoon droughts mainly occur in the west and northwest, winter droughts in the west, and the Rabi and Kharif droughts are more frequent in the north and northwest of Bangladesh. It is expected that the findings of the study will support drought monitoring and mitigation activities in Bangladesh. [ABSTRACT FROM AUTHOR]

A study was conducted for three consecutive cropping seasons at the Central Agricultural Station, Kwadaso, Kumasi in the semi -- deciduous forest zone of Ghana to investigate the seasonal variations of soil microbial biomass carbon, nitrogen and phosphorus under different nutrient management and cropping systems. The field experiment was a split -- plot in a randomized complete block design replicated thrice. Continuous maize cropping (CM), maize/cowpea rotation (M/C) and maize/soybean intercropping (M/S) systems were considered as main plot factors. Poultry manure (PM) at a rate of 4 Mg ha-1, chemical fertilizer (CF) (NPK 15- 15- 15) at a rate of 90 - 60 - 60 kg ha-1, complementary application of poultry manure and chemical fertilizer (PM + CF) at 2 Mg ha-1 PM + 45- 30 -30 kg ha-1 CF and a control (no amendment) constituted the sub-plot factors. Biomass C showed increases over the seasons under nutrient management systems (amendments) and cropping systems. Values recorded in 2006- major rainy season differed significantly (P ≤ 0.05) from values recorded in the subsequent seasons. Unlike biomass C, biomass N recorded highest values in 2006 - minor rainy season. The lowest microbial P values were recorded in 2006 -- minor rainy season which was characterized by P immobilization under all the amendments. Phosphorus was immobilized under cropping systems except in M/S system in the minor rainy season. Biomass carbon to nitrogen ratios (Cmic: Nmic) showed significant differences among amendments during all seasons of cropping and ranged from 3.9 - 35.0. Generally, cropping systems did not have siginificant effect on Cmic: Nmic ratios except in 2006- minor season when CM recorded the highest value of 15.2 with M/S system recording the least (11.9). Soil pH showed positive correlations with Cmic: Nmic ratios in the major rainy seasons but not in the minor season. The study has indicated that efficient seasonal nutrient management under cropping systems could result in buildup of microbial biomass C but may not necessarily lead to corresponding build up in biomass N and P. [ABSTRACT FROM AUTHOR]

Application of chemical fertilizers in smallholder tropical farming systems of South Asia has become mandatory because of soil degradation, and nitrogen (N) is the most abundantly used nutrient. However, integrated management of N with potassium (K) could enhance productivity. Field studies tested the impact of fertilizer K on root development, seed yields, harvest indices, and N-use efficiencies of maize and mungbean, two popular smallholder crops over major and minor seasons. Application of 120 kg K ha-1 optimized all parameters of maize in the major wet season, whereas the requirement was 80 kg K ha-1 in the minor season. Optimal growth yields and N-use efficiencies of mungbean was with 80 kg K ha-1 in both seasons. Information regarding rates of fertilizer K that optimized N use and yield of maize and mungbean during each of the two tropical monsoonal seasons of South Asia is presented. [ABSTRACT FROM AUTHOR]

The common bean is one of the most important crops in Brazil, and Minas Gerais state is one of its largest producers, representing about 15% of the national production. The aim of this study was to evaluate the performance of common bean lineages cultivated during the rainy and winter seasons in the Triângulo Mineiro region, Minas Gerais state, Brazil. In the rainy growing season (sowing in December, 2005) and in the winter season (sowing in May, 2006), the tested lineages were BRS Horizonte, CNFC 8059, CNFC 8065, CNFC 8075, VC-6, VC-7, VC-8, VC-9, VC- 10, VC-11, VC-12, CNFC 10443, CNFC 10453, CNFC 10476, MA-I-2.5, MA-I-8.9, MA-I- 18.13, RC-I-8, CV-46, CV-55 and Z-22, in addition to the controls OP-NS-331 (BRSMG Majestoso), Pérola and BRSMG Talismã and VC-3. In each experiment, a randomized block design was set up with 25 treatments and three replications with a useful experimental plot of 4 m². In the rainy growing season, the yield potential of the most productive lineages varied between 2.69 and 2.78 t ha-1 (VC-9 and VC-10, respectively), and in the winter season achieved 3 t ha-1 (3.01 and 3.00 t ha-1, CNFC 8065 and Z-22, respectively). In general, the lineages were more productive in the winter season though their interaction with the growing seasons indicated distinct performance between them according to season. [ABSTRACT FROM AUTHOR]

Taro is the world's fourth most important root crop in terms of production by weight, behind cassava, potato, and sweet potato, and the second most significant staple root crop in terms of consumption, after sweet potato. However, a shortage of well-adapted cultivars is one of the production problems that contribute to low yields and small planted areas across the country. As a result, genotypes with high production potential and adaptability for local environmental circumstances must be evaluated. During the 2018 and 2019 main cropping seasons, field experiments were done in the North-Bench woreda in the Bench-Sheko zone, south-western Ethiopia, to improve taro production and productivity by evaluating and selecting high yielding taro cultivars. Three improved and one local taro variety were used in the trial, which was laid out in a randomized complete block design (RCBD) with three replications at the North bench location. The data were collected and analyzed by using SAS 9.2 Version statistical software. The study's findings revealed that variety had a significant (P < 0.01) impact on all of the variables considered. Accordingly, combined analysis over years indicated that the highest leaf number per plant (7.76), plant diameter (40.82cm), corm diameter (8.28cm), cormel number per plant (6.10), and total yield (22.34 t/ha) were observed for Boloso-1 variety. The highest value of the number of suckers per plant was also observed for the Boloso-1 variety in both years (8.2 in 2018 and 6.2 in the 2019 growing season). However, combined analysis over years indicated the highest corm length in local variety (12.15cm) followed by Boloso-1 variety (10.34cm). Therefore, based on the overall results of this study, the Boloso-1 variety performed best and was more adapted to the area as compared to other varieties. This variety should be popularized and disseminated to users to boost the production and productivity of taro in the testing location and similar agro-ecologies of the region., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s).)

Shading nets have been increasingly drawing research interest, as they allow us to improve the environmental conditions for greenhouse-grown crops. The effects of two shading nets (50% and 79% shading degree), plus an unshaded control, on yield, mineral composition and antioxidants of perennial wall rocket (Diplotaxis tenuifolia L.-D.C.) grown under tunnels in southern Italy were determined. The shading application resulted in a yield decrease, compared to the unshaded control, except for the highest production under 50% shading in July. The highest yield was recorded in the April–May and May–June and the lowest in July. Similar trends were recorded for plant dry weight, leaf number per rosette and mean weight, but the latter showed the highest value under 79% light extinction in July. The rocket leaves were brighter in the summer cycles than in the spring ones. Leaf nitrate was highest in spring and under 79% shading. Potassium, phosphorus, calcium and magnesium showed the highest values in spring and in the unshaded control. The lipophilic antioxidant activity showed the highest values under the 79% shading net in the spring cropping seasons, whereas in July it did not significantly differ from 50% light extinction. The hydrophilic antioxidant activity always attained the highest values in the unshaded control. The unshaded leaves had the highest total phenol accumulation when grown in April–May and the lowest in July. The total ascorbic acid content was always highest in the unshaded control leaves compared to the shading treatments. Fifty percent crop shading is, therefore, an effective sustainable tool for increasing the yield of perennial wall rocket leaves in July, when the light intensity under the plastic tunnel exceeds the plant requirements, also resulting in a mineral composition that is not significantly different from that of the unshaded crops. [ABSTRACT FROM AUTHOR]