Summer Crop Season Research Articles

Effect of Pruning Severity on Quality of Grapes Cv. Red Globe for Summer Season

Effect of pruning severity on quality of grapes cv. red globe in summer season were studied at Horticulture Orchard, Tamil Nadu Agricultural University, Coimbatore during 2012-2013. The vines were pruned at four different levels in a Randomized Block Design with five replications. TSS, TSS/acid ratio, titrable acidity, sugar-acid ratio, reducing, non-reducing and total sugars for quality parameters were determined. Results revealed that, all the vines which were pruned at 2 bud level for summer season crop registered highest Total soluble solids (17.82 °Brix), TSS/acid ratio (35.95), lower titrable acidity (0.49%), whereas, the maximum reducing sugar (15.65%), total sugars (17.24%) and sugar-acid ratio (34.17) was observed in vines pruned to 50% of the canes for vegetative growth and 50% of the canes for crop yield in summer season and it was found to be better performed among different pruning intensities. Among the pruning intensities the vines which were pruned to 50% canes to 6 bud level and remaining 50% canes to 2 bud level performed better.

Estimation of yearly, monthly and weekly drought for Aurangabad district of Maharashtra

The rainfall distribution of Aurangabad district of Maharashtra state is quite erratic in space and occurrence of drought is common. In this study 21 years (1991-2011) of rainfall data of Aurangabad district have been analyzed on yearly, monthly and weekly basis for predicting the water drought, normal and surplus events for crop planning in the region. Weekly drought normal and surplus events give a more precise idea about crop planning than yearly and monthly events. The analysis has revealed that the percentage of drought weeks was more than normal and surplus weeks. It has been also revealed that there is a need of assured supplemental irrigation facility in Rabi and summer season crops.

Estimation of yearly, monthly and weekly drought for Parbhani district

The rainfall distribution of Parbhani district of Maharashtra state is quite erratic in space and occurrence of drought is common. In this study, 21 years (1991-2011) of rainfall data of Parbhani have been analyzed on yearly, monthly and weekly basis for predicting the water drought, normal and surplus events for crop planning in the region. Weekly drought normal and surplus events give a more precise idea about crop planning. The analysis has revealed that the assessment of drought on weekly basis is very important for better crop planning particularly in rainfed area. As analysis base period decreases the percentage of drought increases subsequently from year to month and from month to week. It has been also reveals that there is a need of assured supplemental irrigation facility in Rabi and summer season crops.

Spatio-temporal performance of large-scale Gezira Irrigation Scheme, Sudan

Information on irrigation indicators is needed to improve irrigation management. The objective of this paper is to assess the irrigation performance of the Gezira Scheme, Sudan. Data on climatic elements, irrigation water supply and crop yield for the period 1961–2010 integrated with remote sensing data from 2000 to 2014 are used. Crop evapotranspirations (ETc) are determined by FAO 56 reference evapotranspiration (ETo) with derived crop coefficients (kc) and the actual evapotranspiration (ETa) is estimated using FAO 33. Irrigation efficiency indicators, Relative Irrigation Supply (RIS) and Relative Water Supply (RWS), are calculated. Potential rainwater supply to crop is tested based on Moisture Availability Index (MAI) and Ratio of Moisture Availability (RMA). Furthermore, Water Use Efficiency (WUE) is used to assess the water productivity. For the spatial drought assessment, a modified Vegetation Condition Index (MVCI) derived from remotely-sensed data is used. The results of RIS and RWS show respectively that the irrigation efficiency has decreased since 1993/1994 from 1.40 and 1.70 to 2.23 and 2.60, respectively. MAI for cotton and sorghum presents moderate deficit values (0.4 to 0.68) in July and August. RMA has an average value of 0.67, 0.49 and 0.46 in July for cotton, groundnut and sorghum, respectively, indicating a promising rainfall contribution to irrigation. The Gezira Scheme achieves low WUE in comparison to many irrigation schemes of the globe. Based on the MVCI analysis, the northern part of the scheme experiences characteristic drought during the summer crop season whereas irrigation water is abundantly available during the winter. In conclusion, the overall water availability is higher than the demand; most likely the rain is not considered in irrigation scheduling. Low productivity is mainly due to poor distribution and irrigation mismanagement. Rain and drained irrigation water harvesting could be addressed in the scheme for balancing the demand and supply.

Response of Arbuscular Mycorrhizal Fungi in Different Soil Tillage Systems to Long‐Term Swine Slurry Application

AbstractSwine slurry is a common agricultural fertilizer in many countries. However, its long‐term use in large amounts can cause excess nutrient accumulation, alter soil compounds, and potentially influence critical microbial populations such as arbuscular mycorrhizal fungi, which have important roles in plant nutrition and soil sustainability. This work determined if arbuscular mycorrhizal status, external mycelium, and glomalin‐related soil protein content were affected by long‐term swine slurry application to different soil tillage systems. The experiment was conducted on a clayey oxisol, in southern Brazil. Swine slurry (0, 30, 60, 90, and 120 m3 ha−1 y−1) was applied for 15 years to conventional tillage and no tillage soil prior to the summer (soybean or maize) and winter (wheat or oats) crop seasons. Swine slurry decreased mycorrhizal root colonization, spore number, and total external mycelium. Swine slurry increased active external mycelium and both easily extractable and total glomalin‐related soil protein. No‐tillage soil had more glomalin‐related soil protein than conventional tillage soil. The most significant response variables were root colonization, easily extractable glomalin‐related soil protein, and total external arbuscular mycorrhizal mycelia. Long‐term application of swine slurry in this environment, even at high rates, did not adversely affect crop yield but did influence arbuscular mycorrhizae fungi and their products in the soil environment. Benefits of swine slurry application for crop nutrition must be weighed against potential adverse consequences for the size, activity, and benefits of the mycorrhizal community to subsequent annual crops. Copyright © 2014 John Wiley & Sons, Ltd.

Five crop seasons' records of greenhouse gas fluxes from upland fields with repetitive applications of biochar and cattle manure

The application of char to agricultural land is recognized as a potential way to sequester atmospheric carbon (C) assimilated by plants in soil, thus decelerating global warming. Such a process would also be expected to improve plant growth and the physical and chemical properties of soil. However, field investigations of the effects of continuous char application have not been reported. In the present study, the effects of repetitive bamboo char application on CO2, CH4, and N2O flux from soil, soil C content, and crop yield were investigated at two upland fields over five crop seasons. Three treatments: chemical fertilizer (CF) applied plots (Control plot); cattle manure (CM) (10 t ha−1) and CF applied plot (CM plot); and bamboo char (20 t ha−1), cattle manure (10 t ha−1), and CF applied plot (Char/CM plot), were arranged in each field. After three crop seasons, the fourth treatment with char was applied without CF (Char plot) was given to one of the fields. CM and/or char were applied every crop season. Gas fluxes were measured using the static chamber method. Seasonal variations in CO2 flux and total CO2 emissions were consistently similar between the CM and Char/CM plots and between the Char and Control plots. As such, the decomposition rate of bamboo char was quite small, and the positive or negative effect of char on CM decomposition was not significant in the fields. Soil C analysis provided confirmation of this. CM application enhanced N2O emission mainly in the summer crop season. The differences in total N2O emission between the Char/CM and CM plots as well as between the Char and Control plots were insignificant in most cases. Total CH4 flux was negligibly small in all cases. Although the yield of winter crop (broccoli) in the Char/CM plots was twice observed to be higher than that in the Control and CM plots at one of the fields, in general, the char application had no effect on overall crop yield. Thus, the repeated application of bamboo char had no significant influence on greenhouse gas emissions and crop yields, but a high C accumulating function was found.

Use of high resolution imagery and ground survey data for estimating crop areas in Mengcheng county, China

The use of remote sensing images in combination with ground survey data was assessed for deriving crop areas over Mengcheng County in 2011 in the North China Plain. First, a stratification of the county into arable land, permanent crops and non agricultural land was carried out by photo-interpreting a grid of points on Google Earth and a 2.5m Spot5 image from 2011. Then a sample of 83 segments was randomly selected in the arable stratum and surveyed with GPS. Two high resolution images (TM 30m and Spot5 10m) were acquired over the 2011 summer crop season and classified using maximum likelihood. The regression estimator was then applied using the surveyed segments and the classification and compared to the direct expansion estimate derived from the segments only; the calibration estimator was also tested using the same classification and the 83 arable points that served as seeds for the segments and compared to the estimate derived from the 83 points alone. The regression estimator proved to be the most efficient one in the North China Plain landscape. To reach the same variance of estimate as the regression estimator, the number of points to be surveyed for the calibration estimator should be multiplied by seven. Last pixel counting tested on the whole county and on the arable points of the grid resulted in biased estimates, in contrast to estimates based on ground data, in combination with remote sensing or not.

Satellite-based investigation of flood-affected rice cultivation areas in Chao Phraya River Delta, Thailand

The occurrence of catastrophic floods in Thailand in 2011 caused significant damage to rice agriculture. This study investigated flood-affected rice cultivation areas in the Chao Phraya River Delta (CRD) rice bowl, Thailand using time-series moderate resolution imaging spectroradiometer (MODIS) data. The data were processed for 2008 (normal flood year) and 2011, comprising four main steps: (1) data pre-processing to construct time-series MODIS vegetation indices (VIs), to filter noise from the time-series VIs by the empirical mode decomposition (EMD), and to mask out non-agricultural areas in respect to water-related cropping areas; (2) flood-affected area classification using the unsupervised linear mixture model (ULMM); (3) rice crop classification using the support vector machines (SVM); and (4) accuracy assessment of flood and rice crop mapping results. The comparisons between the flood mapping results and the ground reference data indicated an overall accuracy of 97.9% and Kappa coefficient of 0.62 achieved for 2008, and 95.7% and 0.77 for 2011, respectively. These results were reaffirmed by close agreement (R2>0.8) between comparisons of the two datasets at the provincial level. The crop mapping results compared with the ground reference data revealed that the overall accuracies and Kappa coefficients obtained for 2008 were 88.5% and 0.82, and for 2011 were 84.1% and 0.76, respectively. A strong correlation was also found between MODIS-derived rice area and rice area statistics at the provincial level (R2>0.7). Rice crop maps overlaid on the flood-affected area maps showed that approximately 16.8% of the rice cultivation area was affected by floods in 2011 compared to 4.9% in 2008. A majority of the flood-expanded area was observed for the double-cropped rice (10.5%), probably due to flood-induced effects to the autumn–summer and rainy season crops. Information achieved from this study could be useful for agricultural planners to mitigate possible impacts of floods on rice production.

Production and nutritional value of sorghum and black oat forages under nitrogen fertilization

AbstractThe effect of nitrogen (N) fertilization on the dry‐matter (DM) yield and nutritional value of sorghum (Sorghum sp., cv. Jumbo) and black oat (Avena strigosa cv., IPR 61) was investigated in the context of forage and livestock production in southern Brazil. Sorghum was cultivated with 0, 37·5, 75, 150, 225, 300 and 375 kg N ha−1 during the summer crop seasons of 2010/11 and 2011/12. Black oat received 0, 40, 80, 120, 160, 200 and 240 kg N ha−1 in the winter of 2011. According to the adjusted polynomial regression, sorghum DM yield increased in response to N up to 288 (12·9 t ha−1) and 264 kg ha−1 (5·6 t ha−1) in 2010/11 and 2011/12 respectively. Crude protein (CP) content of sorghum was highest at 349 and 328 kg N ha−1, but in vitro dry‐matter digestibility (IVDMD) was highest at 212–207 kg N ha−1 in 2010/11 and 2011/12 respectively. Sorghum neutral detergent fibre (NDF) and acid detergent fibre (ADF) were not affected by N fertilization. In black oat, the maximum DM yield (6·0 t ha−1) was obtained with 187 kg N ha−1; the IVDMD, NDF and ADF were not affected by N fertilization, but the CP content increased up to 220 kg N ha−1. It is concluded that these forage species can improve the year‐to‐year amount and quality of forage produced but high rates of N fertilizer are required to achieve high yields. Fertilizer N rates of 210–280 kg N ha−1 in sorghum and 180 kg N ha−1 in black oat in the crop rotation provide the greatest responses in DM yield consistent with good nutritional quality for livestock production.

Performance of Sunnhemp (Crotalaria juncea L.) as a Summer Season (Pre-Monsoon) Crop for Fibre

The field experiments were conducted during the summer (pre-monsoon) seasons of 2008-2009 and 2009-2010 at Sunnhemp Research Station, CRIJAF-ICAR, Pratapgarh, U.P., India to assess the feasibility of sunnhemp cultivation for fibre purpose during summer season after harvest of wheat crop. The experiments were laid out in randomized block design. The data from different experiments indicated that sowing of sunnhemp crop for fibre purpose during 2nd fortnight of April at the spacing of 15cm x 10cm and harvesting at 90 days after sowing recorded higher fibre yield. The summer season crop escaped from the attack of most of the insect pest besides allowing time for the transplanting of rice crop also. The results indicated that sunnhemp could be easily accommodated in prevailing rice-wheat cropping system during summer season.

Climate, vegetation and ecology during Harappan period: excavations at Kanjetar and Kaj, mid-Saurashtra coast, Gujarat

A multi-proxy study was carried out to address climate–culture relationship from two trenches one each from Kaj and Kanjetar (mid-Saurashtra coast) deposited in a lacustrine setting, since ∼1960 Cal BC and ∼2230 Cal BC, respectively. The salinity of aqueous soil solution (0.1 ppt) and fresh water thecamoebians in both the sites indicate fresh water depositional environment. But, an increase in salinity (0.2 ppt) in the top clayey sediment in Kanjetar is attributed to water evaporation through upward capillary action from moisture deficit exposed land. The fragments of ancient potteries and other artefacts recovered from the bottom sediment provide evidences of Sorath-Harappan colonization in the vicinity which was not an urban site. The abundant cyanobacterium remains, low terrigenous organic matter, aquatic pollen and low thecamoebians in bottom sediment indicates low precipitation and arid climatic conditions ∼2000 BC. During this period the dominance of evergreen and moist deciduous arboreals from both the sites do not show equilibrium with the prevailing dry/arid climate and therefore, the pollen assemblage here represents the remnants of wetter middle Holocene vegetation in the region. Phytoliths of drought-tolerant summer season crops also reflects here changes made in the agricultural strategy by Harappans in response to climate. The increase in deciduous arboreal pollen since the last ∼2000 years represents equilibrium with the dry/arid climate. But, enhanced limnic conditions recorded with the help of thecamoebians during this period is attributed to changes in wetland configuration induced by hydrostatic changes in the river mouth that was largely defined by the dynamics of sediment deposition through rain-fed rivers/streams in the region.

Composition and diversity of weed communities in Al-Jouf province, northern Saudi Arabia

The aim of this study was to identify the main weed communities in Al-Jouf province in northern Saudi Arabia. Moreover, the composition and diversity of these communities were studied in relation to soil variables and crop type. Some 54 stands representing olive orchards, date palm orchards, wheat crop and watermelon crop were studied, using ten quadrats (1×1m) per stand. A total of 71 species belonging to 22 families and 61 genera were observed. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) resulted in the recognition of four vegetation groups representing wheat crop, orchards in winter season, orchards in summer season and watermelon crop. These results suggested the importance of both crop and season for the formation of weed community. Detrended Correspondence Analysis (DCA) showed that these groups are clearly distinguished by the first two DCA axes. The species richness was higher in both olive and date palm orchards than in wheat and watermelon crops. This pattern of species richness could be related to farm management practices and habitat micro-heterogeneity. Soil electrical conductivity, organic carbon and soil texture showed significant correlations with species richness and the cover values of some dominant species, suggesting the significant role of soil characteristics in weed community structure and diversity.

Soil microbial biomass under different tillage and levels of applied pig slurry

ABSTRACT The objective of this work was to evaluate the changes in microbial biomass C, N and P due to the application of pig slurry under different soil tillage systems. The experiment was established in a clayey Oxisol, Eutrophic Red Latossol in Palotina, PR. Different quantities of pig slurry (0, 30, 60 and 120 m3 ha-1 year-1) were applied to the soil prior to the summer and winter crop season under conventional tillage (CT) and no tillage (NT), in three replicates. The area was cultivated with soybean (Glycine max L.) or maize (Zea mays L.) in the summer and wheat (Triticum sativum Lam.) or oat (Avena sativa L.) in the winter. The soil samples were collected in March and October of 1998 and 1999 at depths of 0-5, 5-10 and 10-20 cm. The soil tillage and pig slurry application influenced the microbial biomass C, N and P. The microbial biomass and the microbial activity presented high sensibility to detect changes in the soil due to tillage and the application of pig slurry. The soil microbial biomass and Cmic/Corg relation increased as the quantity of applied pig slurry increased. The metabolic quotient under CT increased with depth while under NT it decreased. The soil microbial biomass was enriched in N and P under NT and as the quantity of applied pig slurry increased.

Fate of Pesticides in Combined Paddy Rice-Fish Pond Farming Systems in Northern Vietnam

During the last decades, high population growth and export-oriented economics in Vietnam have led to a tremendous intensification of rice production, which in turn has significantly increased the amount of pesticides applied in rice cropping systems. Since pesticides are toxic by design, there is a natural concern on the impact of their presence in the environment on human health and environmental quality. The present study was designed to examine the water regime and fate of pesticides (fenitrothion, dimethoate) during two consecutive rice crop seasons in combined paddy rice-fish pond farming systems in northern Vietnam. Major results revealed that 5 and 41% (dimethoate), and 1 and 17% (fenitrothion) of the applied mass of pesticides were lost from the paddy field to the adjacent fish pond during spring and summer crop seasons, respectively. The decrease of pesticide concentration in paddy surface water was very rapid with dissipation half-life values of 0.3 to 0.8 and 0.2 d for dimethoate and fenitrothion, respectively. Key factors controlling the transport of pesticides were water solubility and paddy water management parameters, such as hydraulic residence time and water holding period. Risk assessment indicates that the exposure to toxic levels of pesticides for aquaculture (, ) is significant, at least shortly after pesticide application.

Soil enzyme activities under pig slurry addition and different tillage systems

The objective of this work was to evaluate the changes in soil enzyme activities due to application of pig slurry under different soil tillage systems. The experiment was conducted in a clayey Oxisol in Palotina, PR, using different quantities of pig slurry (0, 30, 60 and 120 m3 ha-1 year-1) applied to the soil prior to the summer and winter crop season under conventional tillage (CT) and no tillage (NT), with three replicates. The areas were cultivated with soybean (Glycine max L.) and maize (Zea mays L.) in the summers of 1998 and 1999, respectively, and with wheat (Triticum sativum Lam.) in the winters of both years. The soil samples were collected in March and October of 1998 and 1999 at depths of 0-5 cm, 5-10 cm and 10-20 cm. The pig slurry application and the soil tillage systems influenced enzyme activities in the soil. The increase of pig slurry application decreased the ratio of soil enzyme activities to microbial biomass carbon. The phosphatase activity had a negative relationship with soil-available phosphorus. The acid phosphatase activity decreased both under CT and NT systems at all depth studied due to pig slurry application.

IMPACT OF TIME OF SOWING AND IN SITU SUN DRYING OF COTTON STALKS AND ON THE MANAGEMENT OF COTTON STEM WEEVIL, PEMPHERULUS AFFINIS FAUST

ABSTRACT Impact of time of sowing and sun drying of cotton stalks and on the management of cotton stem weevil , Pempherulus affinis Faust was studied at Cotton Research Station, Srivilliputtur, Tamil Nadu. In early sown cotton crop infestation and plant mortality was more compared to the late sown cotton crop. It was also observed that off season crop (i.e., Winter season crop in the Summer Cotton Tract) was much affected compared to the regular season crop (i.e.,Summer season crop in the Summer Cotton Tract). Weevil emergence was nil from sun dried cotton stalks kept under sun in situ after pulling out. But weevil emergence was observed in stored / heaped cotton stalks. Importance of in situ drying of cotton stalks after pulling out the cotton stalks to arrest the carry over of the pest to next season is brought out in the present study

EFFECT OF PRECEDING WINTER CROPS, RELAY CROPPING, INTERCROPPING SYSTEM AND NITROGEN FERTILIZER RATES ON SOME SOIL PHYSICAL, HYDROPHYSICAL AND CHEMICAL PROPERTIES

Field experiments were carried out on clay soil at the experimental farm of El-Gemmeiza Agricultural Research Station, El-Gharbia governorate, during two years (2006 and 2007), to investigate the effect of preceding winter crops, relay cropping, intercropping system and N fertilization levels on soil properties. The experiments were conducted in randomized complete block design in a split–plot, with three replicates, where preceding winter crops (i.e., wheat, sugar beet and faba bean) occupied the main plots and nitrogen fertilizer rates for maize plant (90, 105, 120 and 135 Kg N/fed.) were assigned to the sub plots, in both years. Results can be summarized as follows:- 1- All preceding winter crops induced significant changes in all soil properties under study, but faba bean was more effective than wheat or sugar beet on decreasing the values of soil bulk density (Db), settling %, water consumption (CU), soil reaction (pH), soluble Ca, Mg and HCO3 andC/N ratio of the soil, where take the following order: faba bean > sugar beet > wheat. On the other hand, the effects of preceding winter crops on total porosity (E), void ratio (e), pore size distribution (>9µ, 9-0.2 µ and <0.2 µ), hydraulic conductivity (Kh), soil moisture content (θw) just before harvesting, saturation percentage (SP), field capacity (FC), wilting point (WP), available water (AW), water use efficiency (WUE), soil salinity (EC), soluble Na, K, Cl, SO4, total N, organic carbon (OC) and availability of soil macronutrients (N, P and K) were increased these characters and take the same order. 2- Faba bean planting as a preceding winter crop with the addition of 90 Kg N/fed to maize in summer season gave the lowest values of (CU), while faba bean with 135 Kg N./fed to maize was the best treatment, since it gave the highest value of (WUE) in the first and second years. 3- The addition of 135 Kg N/fed resulted in a decrease of (pH), soluble HCO3 and C/N ratio of the soil and increase in (WUE), total N, organic carbon (OC) and availability of soil macronutrients (N, P and K). 4- It could be concluded that the sowing of faba bean, sugar beet and wheat plants in winter season, relay cropping and intercropping system with increasing nitrogen fertilizer for summer crops led to a markedly improvement in soil physical, hydrophysical and chemical properties as well as the status of nutrients which reflect on higher yield of summer season crops.

경남지방에서 조사료 주년생산 작부체계에 관한 연구

주년 조사료 생산을 위한 작부체계에서 하계작물에서는 수수<TEX>${\times}$</TEX>수단그리스 교잡종이 청예수량이 가장 많았고, 다음이 옥수수이었으며, 건물수량은 옥수수>수수<TEX>${\times}$</TEX>수단그라스 교잡종>수수>귀리의 순이었다. 작부체계에서 동계작물의 종류가 하계작물의 청에 및 건물생산에 미치는 영향을 검토한 결과 통계적 유의성을 볼 수 있었다. 동계작물들의 청에 및 건물 생산량은 5월 중순 예취시 귀리가 가장 많았으며, 트리티케일>이탈리안 라이그라스>호밀>청보리의 순이었다. 앞작물로 재배된 하계작물의 종류가 동계작물의 청예 및 건물수량에 미치는 영향은 적은 것으로 보였다. 하계작물의 사료가치는 귀리가 조단백질 함량이 가장 높았으며, ADF는 수수, 그리고 NDF는 수수<TEX>${\times}$</TEX>수단그라스 교잡종이 다소 높았다. 또한 옥수수가 RFV와 TDN이 가장 많았다. 동계작물의 사료가치는 조단백질 함량은 귀리가 가장 높았으나, ADF와 NDF 등의 섬유소 함량은 작물간 큰 차이를 보이지 않았다. RFV는 호밀과 트리티케일에서 높았으며, 귀리가 다소 낮은 경향을 보였다. 한편 TDN 함량은 트리티케일에서 가장 높게 나타났다. 주년 조사료 생산을 위한 작부조합별 건물 생산량은 옥수수와 호밀, 옥수수와 트리티케일에서 가장 높아 유망한 작부체계로 보였다. 한편 옥수수와 트리티케일, 옥수수와 호밀, 그리고 수수<TEX>${\times}$</TEX>수단그라스 교잡종과 트리티케일/호밀의 작부체계가 TDN 생산량을 고려할 때 유망한 작부조합으로 나타났다. 토양 pH, EC 및 유기물 함량은 시험전에 비해 시험후에 높아지는 경향이었다. 예취시기별 동계작물의 사료가치를 검토한 결과 조단백질 함량은 4월 중순보다 5월 중순 예취시 많았으며, ADF와 NDF 함량은 수확시기가 늦어질수록 증가 하였다. 또한 RFV와 TDN 함량은 생육후기로 갈수록 낮아졌다. Present experiment was conducted at the field of Gyeongnam Agricultural Research and Extension Services in Jinju city for two continuous cropping seasons to develop several adaptable and valuable year-round forage-producing system for elevating self-sufficiency and dollar-saving by reduced importing of crude forage. Twenty cropping systems were tested in experiment using whole crop barley (WCB), oat, rye, Italian ryegrass (IRG), and triticale in winter season and com, sorghum, sorghum <TEX>${\times}$</TEX> sudangrass hybrid, and oat in summer time. Sorghum <TEX>${\times}$</TEX> sudangrass hybrid showed highest fresh forage yield among experimented summer season crops, and followed com. Com produced the most dry matter yield, and followed sorghum<TEX>${\times}$</TEX>sudangrass hybrid, sorghum and oat in order. There was no significant effect of former winter crops on fresh and dry matter production succeeding summer time crops. Among winter season forage crops tested, oat showed the highest fresh and dry matter when clipped on mid-May, and followed triticale, IRG, rye and WCB. Winter-time cultivated crops showed no clear effect on the growth and forage (fresh and dry matter) producing ability of following summer crops. There was the most protein content in oat plant among summer season planted crops, and in sorghum for acid detergent fiber (ADF) and in sorghum <TEX>${\times}$</TEX> sudangrass hybrid for neutral detergent fiber (NDF), respectively. While, com showed highest value of relative feed value (RFV) and total digestive nutrients (TDN) among those crops. Among winter crops, the highest crude protein was in oat plant showing no significant differences of ADF and NDF, while, relatively higher value of RFV was recognized with rye and triticale. Also, triticale contained more TDN as compare to other forage crops. The cropping combinations such as com followed by (fb) rye and maize fb triticale were regarded as promising systems having higher dry matter producing ability among tested combinations. Considering TDN producing potential, the combinations with sorghum <TEX>${\times}$</TEX> sudangrass hybrid fb triticale andlor rye were would be suitable ones, coincidently. There was a tendency which elevating pH, electric conductivity (EC) and organic matter (OM) contents in soil after experiment comparing to before planting. More crude protein content in plant was shown at mid-May clipping as compared to the forage at April cut in all winter season grown crops. ADF and NDF contents were increased by delayed clipping showing decreased tendency of RFV and TDN in plant. In conclusion, many cropping systems would be available using above mentioned forage crops according to farmer's conditions and scale, etc.

Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

The main goal was to understand the trends of actual evapotranspiration (AET) and crop coefficient (&lt;I&gt;K&lt;sub&gt;c&lt;/sub&gt;&lt;/I&gt;) in summer and winter seasons crops in Japan, maize, soybean, wheat and Italian rye-grass. Bowen ratio energy balance technique (BREB) was applied to measure the AET and heat flux between ground surface and atmosphere. Measurements were carried out using an automatic weather station (AWS) installed seasonally in the experimental farm of Tokyo University of Agriculture and Technology (TUAT). Penman-Monteith equation recommended by FAO was used to calculate reference crop evapotranspiration (ET&lt;SUB&gt;0&lt;/SUB&gt;) and &lt;I&gt;K&lt;sub&gt;c&lt;/sub&gt;&lt;/I&gt; was obtained from the ratio of AET to ET&lt;SUB&gt;0&lt;/SUB&gt;. The results indicated that the average amount of daytime AET in the winter and summer seasons crops were approximately 2.5 and 3.5 mm, respectively monthly daytime. Daytime AET varied between 1.3 and 5.7 mm in winter season crops and between 1.4 and 6.5 mm in summer season crops. No significant differences between daily average values of AET for winter season as well as for summer season crops were found at 5% level of confidence (&lt;I&gt;t&lt;/I&gt; = 0.9278, wheat and Italian rye-grass and &lt;I&gt;t&lt;/I&gt; = 0.6781, soybean and maize). Average &lt;I&gt;K&lt;sub&gt;c&lt;/sub&gt;&lt;/I&gt; values of summer season crops were found to be slightly higher than those of winter seasons crops. For planning the irrigation scheduling, it is quite necessary to understand the behaviors of AET and &lt;I&gt;K&lt;sub&gt;c&lt;/sub&gt;&lt;/I&gt; during the growing season.

Natural Survivorship of Immature Stages of Culex vishnui (Diptera: Culicidae) Complex, Vectors of Japanese Encephalitis Virus, in Rice Fields in Southern India

Abstract The development and survival of immatures of Culex vishnui (Diptera: Culicidae) complex, vectors of Japanese encephalitis virus, were studied in transplanted rice, Oryza savita L., fields during three crop growing seasons. The total duration of development from the first instar to adult emergence varied from 6 to 8 d. Survival rate estimates ranged from 0.003 to 0.524, but they generally were &amp;lt;0.1. Unusually high survival rates (0.192–0.524) were observed in summer and long-term monsoon crop seasons during 1993. A multiple regression method using backward elimination was used to analyze the factors responsible for these variations. The model identified nine parameters related with survival rates that explained 99% of the variance. Area of water surface and hardness were negatively related, whereas green algae, notonectid adults, anisopterans, dytiscids, salinity, water depth, and dissolved oxygen were positively associated with immature survival.