Research study on seed physical property of Mongolian wheat varieties

Four corn varieties, each representing early, medium and late maturity were sown respectively at various times from April 30 to August 5, and their fresh weight was investigated in 1959 and 1960 at the kikyogahara Branch of Nagano Agricultural Experiment Station. The results obtained were as follows: 1. Fresh weight of early maturing variety planted somewhat late is comparatively heavier than that planted at the other dates. While, fresh weight of late maturing variety planted earlier is heavier than that planted at the other dates. Increase in culm length shows a tendency similar to that of fresh weight throughout the growth period. In this respect, medium maturing variety shows the intermediate tendency between those of early and late maturing varieties. 2. Days from emergence to tassel differentiation are less in the cases of later planting. The time of tassel differentiation of early maturing variety is earlier than those of later maturing ones. The tassel of early variety initiates before the lowest internode begins to elongate. The duration of the lowest internode elongation is constant among varieties, if they are seeded at the same time. 3. Days from emergence to tassel differentiation or to the time of the lowest node elongation are affected by mean temperature and are scarcely affected by day length during the course of plant growth. 4. The fresh weight at the time of young tassel formation is varied according to planting time and also to varieties. 5. Fresh weight of plants during the time from the lowest ioternode elongation to tasselling is affected by temperature in the case of early maturing variety, while those of the medium and late maturing variety are affected by day length as well as by temperature. Extreme late maturing varieties are affected mainly by photoperiod. The earlier the tassel differentiation begins the less fresh weight is. 6. In early maturing variety, the degree of elongation of the lower internodes is remarkable when planted somewhat late. When planted extremely late, the elongation of the upper internode is inhibited by low temperatre and the number of nodes decreases. The elongetion rates of upper internode ate affected ramarkably by low temperature in the case of late maturing varieties planted rate, while the elongation of lower internode is promoted in the preceeding warm condition. Therefore in later maturing variety, the culm length of earlier planted one is longer than that of later planted one.

본 시험은 숙기가 다른 호밀 4품종(조생종=‘Koolgrazer’, 중생종=‘Homil22’ 및 만생종=‘Danko’)을 공시하여 수확시기를 4월 20일, 4월 26일 및 5월 4일로 달리하였을 때 호밀의 사초수량과 품질을 비교하기 위하여 천안연암대학실습농장에서 2001년에서 2002년까지 수행하였으며 얻어진 결과는 다음과 같다. Koolgrazer, Homil22 및 Danko의 출수기는 각각 4월 17일, 22일 및 29일 이었다. 건물률은 수확시기가 4월 10일에서 5월 4일로 늦어짐에 따라 15.6%에서 21.6%로 증가하였다. 한편 품종간 비교에서는 Koolgrazer, Homil22 및 Danko가 각각 20.9, 1838 및 16.3%로 Koolgrazer가 가장 높았다. 호밀의 건물수량은 수확시기가 늦어짐에 따라 ha당 11.2톤에서 13.9톤으로 증가하였으나, 호밀품종간에는 유의적인 차이가 없었다. 가소화영양소 총량(TDN) 수량은 수확시기가 늦어짐에 따라 ha당 7.4톤에서 8.4톤으로 증가하였으며 한편 품종간에는 유의적인 차이가 없었다. 조단백질 함량은 수확기기가 늦어짐에 따라 20.3%에서 17.1%로 감소하였으며, 품종 중에서는 만생종인 Danko가 Koolgrazer 및 Homil22보다 높았다. 섬유소 함량(NDF, ADF, ADL, Hemicellulose 및 Cellulose)에서는 만기수확인 5월 4일이 수확시기 중 가장 많았다. 한편 호밀의 품종간 비교에서는 조생종인 Koolgrazer가 중생종과 만생종인 호밀22 및 Danko보다 섬유소 함량이 많았다. Cellulase에 의한 유기물 소화율은 수확시기가 늦어짐에 따라 감소하였다. 품종간 비교에서는 조생종인 Koolgrazer가 가장 낮았다. 호밀의 품종과 수확기기간에는 사초생산성 뿐만아니라 품질에서도 유의적인 차이가 있었다. 사초생산성이 최대이고 적정 품질을 위한 조생종인 Koolgrazer 시기는 4월 24일에서 4월 28일, 종생종인 Homil22는 4월 29일에서 5월 3일, 만생종인 Danko는 5월 4일에서 5월 8일이라고 생각된다. This experiment was conducted at Cheonan Yonam Experimental Livestock Farm in 2001-2002 to detennine the effect of harvest date(20 April, 26 April and 4 May) on forage yield and quality of rye varieties of three different maturing groups(early maturing variety = ‘Koolgrazer’ midseason maturing variety = ‘Horni122’ and late maturing variety = ‘Danko’). The heading date of Kooigrazer, Hornil22 and Danko were 17, 22 and 29 April, respectively. Dry matter percentage increased from 15.6 to 21.6% as the harvest date was delayed from April 20 to May 4. Among the rye varieties tested, dry matter percentage of Koolgrazer, Hornil22 and Danko were 20.9, 18.8 and 16.3%, respectively. Dry matter yield increased from 1l.2 to 13.9 ton/ha as the harvest date was delayed, but no significant difference among rye varieties. As the harvest date was delayed, total digestible nutrients(TDN) yield also increased significantly from 7.4 to 8.4 ton/ha However no significant difference was found among rye varieties. Crude protein(CP) percentage decreased from 20.3 to 17.1% as the harvest date was delayed, and CP percentage of late maturing variety, Danko, was significantly higher than that of the other varieties. In content of fiber component(NDF, ADF, ADL, hemicellulose and cellulose) of rye, the late harvest date(4 May) showed the highest among harvest dates. From comparisoo within rye varieties tested, Kooigrazer, a early maturing variety had higher than a rnidseason and late maturing varieties, Hornill22 and Danko. The cellulase digestible of organic matter of dry matter(CDOMD) decreased as the harvest date was delayed. Among the rye varieties tested, the CDOMD of a early maturing variety, Koolgrazer was the lowest. Our study differences of winter rye in forage yield and quality resulting from variety maturity and harvest stage. A early maturing variety, Kooigrazer should be harvested between 24 and 28 April, Hamill 22(midseason maturing variety) harvested between 29 April and 3 May, Danko(late maturing variety) harvested between 4 and 8 May for maximum forage yield and optimum quality.

Relevance and methods. Research work for breeding purposes was conducted in the context of ISA-branch center FNAC VIM in 2016–2018 G. G. the article presents the results of studies of gen-otypes of soft winter wheat in the collector’s nursery in 20162019 Material for the study were 14 varieties (early maturing and late maturing varieties). The purpose of the work is to study and select varieties based on the elements of plant productivity and adaptability in the conditions of the Central non-Chernozem region.Results. According to the results of assessing the yield of winter wheat varieties in the Ryazan region, it was found that the average yield for 2016–2019 for early — maturing varieties was 5.9 t/ha, for late-maturing varieties-6.9 t/ha. On average, over the years of research, it was noted that higher yields were observed in early — maturing varietiesMironovskaya 29 (5.6 t/ha), Mironovskaya 63 (5.4 t/ha), late-maturing varieties DSV 1113 (7.3 t/ha) and MV Nador (6.4 t/ha). The coefficient of yield variation ranged from 17.3 to 23.8% for early-maturing varieties, and from 14.1 to 24.0% for late-maturing varieties. Based on the conducted research, it was found that the highest resistance to stress of early-maturing varieties was shown by Svet — Toch (-3.4) and Mironovskaya 29 (-3.8), and late-maturing varieties-Scepter (-5.7). Mironovskaya os-tistaya (-6.9), Mironovskaya 63 (-6.7), and DSV– 1113 (10.8) and Tambor (-10.7) had the lowest stress tolerance in early maturing varieties. The maximum genetic flexibility in early — maturing varieties was observed in Mironovskaya ostista and Mironovskaya 63 (5,6), and in latematuring varieties-Iststar (8,0).

Early and late maturing varieties of corn plants were planted during the period from April 30 to July 6. The following conclusions were drawn out from this experiment. The grain yield of early maturing variety planted somewhat late is comparatively more than that planted at the other times of the season. On the other hand, grain yield of late maturing variety planted earlier is more than that of late planted ones. In the case of early maturing variety, dry matter weight per plant is less in the earlier planted one than those in somewhat late planted ones throughout the growth period. In the case of late maturing variety, during the early stage of growth period, accumulation of dry matter in early planted one is more than those in the later planted ones. During the time from early stage of growth period to silking, increase in dry matter weight of early planted one shows the tendency almost similar to that in the later planted ones. After silking, increase in dry matter weight of early planted one is accelerated more than that in the later planted ones. Increase in nitrogen and carbohydrate content seemes to be similar to that in dry matter weight throughout the growth period. Early maturing variety is insensitive to day length. Therefor, once the plant has accomplished its basic vegetative growth, tassel primordium differentiates even under long day regime. Assimilated carbohydrates are accumulated in grains under ideal condition throughout the ripening period in early as well as in middle planted ones, however, vegetative growth of the former is less strong than that of the latter, because the former plant has grown under lower temperature than the others during the course of vegetative growth. In consequence, amount of carbohydrate accumulated in grains is less in early planting. Plant growth and yield of early maturing variety planted late are less than those planted at the other time of season due to the same reason as the case of late maturing varieties planted late. On the other hand, late maturing variety is sensitive to day length. Tassel primordium does not differentiate untill day length become shorter, so amount of vegetative growth is more than that of early maturing variety. In late planting, however shorter day length restricts vegetative growth and lower temperature during ripening period degresses photosynthesis and accumulation of cabohydrate in grains, and these bring decrease in yield finally. Grain yield is better when seeds are planted earlier.

Recently the chemical control of injurious insects became remarkably effective but resistant varieties must be used as the basal practice in agriculture for the purpose of increase in yields of crops.Although the breeders have exerted themselves to originate resistant varieties but excellent results are not obtained so easily, because the factors relating to resistance have to be take out from various compound factors. Most of the main factors related to insect resistance must be hereditery, therefore it is considered that these factors are contained within the seeds of plants. If so, the insect resistance of varieties may be compared with each other by the method which makes insect injure seedlings in the stage before the weaning period. Namely, in this stage the seedlings are depending upon the nutrition of albumen only, but not on fertilizers in soil.In this standing the authors have studied the varietal difference of injury caused by the feeding of rice stem maggot which is known to have remarkable varietal difference. The adults used in this investigation were collected from the field in the beginning of October and then were reared on Agrostis matsumurae HACK. (A. perennans matsum. non TUCK. pro parte.), cereal weed till oviposition. The eggs laid on the surface of said weeds were floated on the water in an experimental dish, with the leaves. After about a week the larvae hatched out and fell into the water. On the other hand, the seedlings of rice plants in the stage before the weaning period were cultured under constant temperature.Thus the artificial parasitisms of the larvae on seedlings were conducted and the seedlings were moved into an incubator of 25°C constant. The survivals and the body length of the larvae were surveyed about 10 days after artificial parasitisms because it was known, from the preliminary test, that the larvae reared on seedlings grew to the 3rd instar after 10 days from artificial parasitism.The results obtained are summarized as follows:1. There were considerable differences in the survivals of each instar but it was clear that the coincidental tendency in the total survival percent and the percentage of individuals that grew to 2nd and 3rd instar larvae, and the correlation coefficient between these two percentages is 0.9401.2. There were correlations between the total survival per cent (x) of larvae bred on seedlings and the number of injured panicles per 20 hills (y) of each variety observed in the field, and the correlation coefficients and the regression equations of each varietal group which was grouped by their heading date were r=0.8565 and y=45, 76+1.17x in early maturing varieties, r=0.9975 and y=1.25 x-7.96 in medium maturing varieties, and r=0.7088 and y=4.12+0.62x in late maturing varieties, respectively.3. The correlation coefficient between the total survival per cent (x) and the mean body length (y) of larvae bred on seedlings was 0.8273 and the regression equation was y=1.250+0.025x, and this equation agreed with 99% probability in any groups of varieties.4. The close correlation between the mean body length (x) of larvae bred on seedlings and the number of injured panicles per 20 hills (y) of each variety observed in the field was recognized, and the correlation coefficients and the regression equations of each varietal group were r=0.8540 and y=41.89x-7.71 in early maturing varieties, r=0.5284 and y=39.90x-40.58 in medium maturing varieties and r=0.8193 and y=22.16x-19.74 in late maturing varieties, respectively.5. From the observation on injured features of seedlings, the clear border of eating marks were recognized in the varieties on which larvae showed good growth

Light, temperature, water are important factors affecting the formation of rice yield. In order to investigate the response of different growth types of rice to climate factors under different sowing dates in Taihu region of Jiangsu province and to provide the basis for reasonable sowing date arrangement of different growth type varieties in the region, two different growth types with high-quality early maturing line Su 1785 and late maturing variety Suxiangjing 100 were planted at different sowing dates from 2018 to 2019 in the experimental farm of Suzhou Academy of Agricultural Sciences. The results showed that the yield of varieties with different growth stages decreased with the delay of sowing date. The yield variation of late maturing varieties was larger than that of early maturing varieties during sowing dates and years, and the stability of yield was poor. The effective panicles and the total grains per panicle of two varieties at different growth stages decreased with the delay of sowing date, while the differences of sowing dates of seed-setting rate and 1000-grain weight varied with different growth types. Early sowing dates significantly reduced the seed setting rate of early maturing varieties, while late sowing dates significantly decreased 1000-grain weight of late maturing varieties. The effects of sowing dates on photosynthetic production before heading stage of early maturing varieties were significantly higher than that of late maturing varieties, while the effects on dry matter accumulation and population productivity after heading stage were opposite. Under the condition of late sowing dates, the stem sheath matter export rate and translocation rate of late maturing varieties decreased rapidly, which was not conducive to the transport of stem sheath materials and accumulation of filling materials. The correlation analysis showed that sunshine hours were the first most important climatic factors affecting rice yield. The effects of daily average temperature and effective accumulated temperature on rice yield varied with different growth types. Daily average temperature and effective accumulated temperature were significantly positively correlated with the yield of early maturing varieties, but not with late maturing varieties. The effects of climate factors on yield were as follows: sunshine hours > average daily temperature, and effective cumulative temperature > precipitation.

Oats are widely used in cold regions as forage and grain crop, with early maturing oat varieties having long planting history. More attention is paid to variety maturity, including both naked and hulled types, for production in cold regions. Despite wide planting of early maturing oat in the cold regions in China, no systematic evaluation on yield and quality of the oat varieties in these regions has been conducted. Qinghai and Inner Mongolia are typically cold regions in China due to high elevation and high latitude respectively, and are representative areas for experimentation on growing oats in cold regions. In this study, we tested production and quality of early and late maturing oat varieties at five locations in Qinghai Province and one location in Inner Mongolia Autonomous Regions. We measured several growth, yield and quality parameters of four early maturing and three late maturing oat varieties in the former locations and six early maturing and one late maturing oat varieties at the latter locations. Parameters measured included leaf length, leaf width, panicle length, dry forage yield, seed yield crude protein and others. Attention was primarily paid to oats maturity due to the emphasis on forage and crop productivity without cons derma for to what the varieties were naked and hulled. The results showed that, in the regions of Qinghai Province with high altitude, forage yield and quality parameters of the early maturing varieties were not significantly different from those of the late maturing varieties. However, seed yield of the early maturing varieties (3702 kg/hm2) was significantly higher than that of the late maturing varieties (2759 kg/hm2) ( P <0.05). In the regions of Inner Mongolia with high latitude, the dried forage yield (3209 kg/hm2) and seed yield (8110 kg/hm2) of the early maturing varieties were significantly higher than those of the late maturing varieties. But the crude protein content in the early maturing varieties was not significantly with late maturing varieties. Our study shows that production and properties of early maturing oats used for forage and grain is similar to normally higher yielding late maturing oats, indicating that early maturing oats are better than late maturing varieties to the short grow season in cold regions. Therefore, early maturing oat varieties should be used as both cereal and forage in the cold regions.

The authors have investigated and examined the internode elongation in relation to the process of the ear emergence of rice plant, continually from the last report. In general the number of elongated nodes of rice plant was found to increase with a individal which has produced many leaves on a main culm within a same variety grown under a same cultural condition. Also the number of elongated nodes varies with different varieties and cultural season. Especially, regarding to cultural season, the individuals which have many elongated nodes tend to increase in number in the case of late planting of late maturing variety. This appearance may be due to a multiple action of day-length and atmospheric temperature change caused by the transfer of cultural season, but may mostly be due to the influence of atmospheric temperature. Thus, the number of elongated nodes in early or late maturing variety as well as the time of initiation of internode elongation may be determined by these factors. As we had suggested in the last report that the limiting or optimum atmospheric temperature for the period of young panicle differentiation of rice plant was not the same for the maturing time, we now ascertained that the time of the young panicle differentiation was not same as the time of internode elongation in case of early maturing variety and that they were same in case of late maturing variety. In other words, we considered that the atmospheric temperature necessary for the young panicle differentiation is different with the one for the internode elongation in case of early maturing variety, but both are about same in case of very late maturing variety. Accordingly, the number of elongated nodes of late maturing variety which has more elongated nodes than early one depends upon the temperature circumstances. And generally, the upper elongated internodes (1st, 2nd, 3rd internode as counted from ear-neck) which occupy the large part of culm length among all elongated internodes may be controlled greatly by low temperature, and on the contrary, the lower elongated internodes (4th, 5th, 6th internode as counted from ear-neck) which occupy a small part of culm length will elongate even by a little higher temperature than the limiting temperature. Therefore, in case of very late maturing variety, which has many elongated internodes and a short range from optimum temperature for young panicle differentiation to one for internode elongation, variation of number of elongated internodes will be observed frequently. On the other hand, in case of early maturing variety, the optimum temperature for young panicle differentiation differs from the one for internode elongation, so that the increase or decrease in number of elongated internodes or in culm elongation is less than these of late maturing variety. Moreover it is presumed that this phenomena might be promoted to some extent by the other factor the response to day-length of varieties.

This study was conducted to assess the suitability of two fallow species that are indigenous to West Africa, M. thonningii (Schum and Thonn) and P. santalinoides (L'Her), for alley cropping with maize and their effect on soil chemical properties. It was carried out during the rain-fed cropping season at Ibadan, Nigeria and Mbalmayo, Cameroon in 1993 and 1994. Total dry matter of P. santalinoides prunings was higher at the two sites than that of M. thonningii by about 35% to 37%. Maize grain yield in plots supplied with prunings was significantly higher (P > 0.05) than in control (no prunings or fertilizer application) at Ibadan. Grain yield in plots supplied with prunings plus 40 kg ha−1 urea fertilizer gave significantly higher yields than plots supplied with 80 kg N ha−1 urea fertilizer only. At Mbalmayo, there was no significant difference between grain yield in plots supplied with 80 kg N ha−1 and plots supplied with prunings plus 40 kg N ha-1 urea fertilizer though the latter had higher yields. Grain yield was also higher in the middle rows than in rows adjacent to the hedgerows and these were not significantly different. Weed dry matter was reduced by 27% to 43% when Pterocarpus prunings were applied and 13% to 31% with application of Millettia prunings. Weed flora in both locations changed from grasses to broad leaved. Soil chemical changes at soil depth 0 to 10 cm showed significant increases (pH, C, N, P and Ca) after two cropping seasons in plots supplied with prunings or prunings plus fertilizer than the initial values. At Mbalmayo, K was lower after cropping in treatments than the initial values while at Ibadan, K and Mg were lower except in plots supplied with Pterocarpus prunings only. P. santalinoides and M. thonningii have significant potential for agroforestry in this sub-region.

An improved water-use efficiency for maize grown under regulated deficit irrigation

Varietal responses of heading date, number of main culm leaves and leaf emergence interval have been investigated with 48 paddy rice cultivars differing date of maturity under five different levels of temperature using semi-open air controlling cabinets. Early maturing varieties tend to be more sensitive to temperature in heading and late ones show less sensitivety. But the relative order of heading date among varieties is rather stable and little disturbed by temperature treatments. Varietal responses to temperature in heading are explained in terms of number of main culm leaves and leaf emergence intervals in the following way. 1) When early maturing varieties are grown urLder warm condition, the leaf extension is accelerated and leaf emergcrence intervals are remarkably shortened. Also number of main culm leaves decreases under high temperature. They have large variability in heading: date under different air temperatures. 2) The situation is different in late maturing varieties. When they are grown under warm environment, the leaf emergence intervals are shortened on one hand, but numberof main culm leaves increases on the other hand. On the contrary late maturing varieties, grown under cool enviromrrent are slow in extending leaves but develop smaller number of leaves. In consequence late maturing varietis are less variable in heading date under various temperature conditions.

Nitrogen trials were carried out on hemp crops grown in Ireland over a 3 year period to identify nitrogen fertilization strategies which optimize the greenhouse gas (GHG) and energy balances of hemp crops grown for biomass. Nitrogen rates up to 150 kg N ha−1 were used in the study. Yield increased with nitrogen rate up to 120 kg N ha−1 for early (Ferimon), mid (Felina 32) and late maturing (Futura 75) varieties. Variety had a significant effect on yield with yields increasing with maturation date. In 2 years of the study, certain application rates of nitrogen were applied either at sowing, at emergence, after emergence or split between these dates to determine if nitrogen rates could be reduced by delaying or splitting the applications. The application of nitrogen at times later than sowing or in splits during the early part of the growing season had no significant effect on biomass yield compared with the practice of applying nitrogen at the time of sowing. Late applications of nitrogen reduced leaf chlorophyll content and height early in the growing season. Later in the growing season, there was no difference in height between treatments although the highest concentrations of chlorophyll were found in the leaves of the late application treatment. Nitrogen rate and the timing of nitrogen application had no effect on plant density. Biomass yield, net energy and net GHG mitigation increased up to an application rate of 120 kg N ha−1, this result was independent of soil type or soil nitrogen level. Net GHG and energy balance of hemp crops grown for biomass are optimized if late maturing varieties are used for biomass production and a nitrogen rate of 120 kg ha−1 is applied at sowing.

This study evaluated water use efficiency (WUE) of selected hybrid maize (Zea Mays L.) varieties in Zambia under rain-fed conditions. A randomized complete block field experiment was carried out during the 2014/2015 rainy season at the University of Zambia Agricultural Demonstration Centre. Treatments were 30 maize varieties from the early, medium and late maturity classes. WUE was calculated as the ratio of yield to evapotranspiration (ET) and transpiration (T). Results showed significant differences in WUE dry matter (DM) for transpiration (T) of early maturing varieties. However, no significant differences were observed in WUEDM for evapotranspiration (ET), WUE grain yield (GY), T and WUEGY, ET. WUEDM, T, WUEDM, ET, WUEGY, T, and WUEGY, ET were statistically the same among medium maturing varieties. Results further showed that among the late maturing varieties, WUEDM, T, WUEDM, ET and WUEGY, T showed significant differences but no significant differences were observed in WUEGY, ET. It was concluded that maize varieties from the same maturity classes have different WUEs. The study thus provided options in variety selection based on which varieties performed better, particularly SC 525, SC 513 and PAN 4M 21 from the early maturity class; PHB 30G19, ZMS 606, MRI 634 and SC 637 from the medium maturity class; and PAN ZM 83, SC 709, PAN 8M 93 and SC 719 from the late maturity class. It was recommended however, that repeated experiments over time should be done to validate the findings given that the trial was only conducted in one season.

One of the most important characteristics of modern strawberry cultivars is fruit size, whitch is estimated in the course of selection on the basis of the single fruit weight. The profitability of crops depends on the level and quality of production, the possibility of capitalization, but also on production costs, which should be as low as possible. The present study aims to analyze the economic efficiency in case of strawberry culture experiments performed with different culture technologies: ten cultivars, three different mulches and two fertilizers . Indicators of economic efficiency (unit cost of production, unit gross profit, profit rate, labor productivity, production costs on equivalent product) were calculated for each variant separately . Biological material was ten genotipes of strawberry, gruped in three maturing varieties [(early maturing: ‘ Alba’, ‘Premial’), medium maturing varieties (‘Kimberly’, ‘Korona’, , ‘Elsanta’, ‘Vima Zanta’) and late maturing varieties (‘Elliany’ ‘Viktoriana’ ‘Virena’, ‘Vima Xima’)], in the form of strawberry runners. The second experimental factor having three graduation was type of mulch (agro-textile, 0,04 mm thick black polyethylene and straw) and the third experimental factor fertilizer systems [poultry manure and chemical fertilizer (NPK complex 28:8:16 ratio)] . The research is based on a comparative analysis of revenue and expenditure per hectare of cultivation and the production results obtained in comparative experiments. Late maturing cultivars, being a productive varieties, which during all experimental years registered the highest production, is ranked first in terms of profit. The selling price level influences the achievement of a high uniform profit, also influenced by the adjustment mechanism of market supply and demand , depending on the seasonality of production. Normal 0 21 false false false RO X-NONE X-NONE

This study was done in Nyando, Kenya to model maize production under different climate scenarios and project the yields up to 2030 and 2050 using Decision Support System for Agrotechnology Transfer (DSSAT) under rain fed conditions. Three maize varieties were used; Katumani Comp B as early maturing variety, Hybrid 511 as a medium maturing variety and Hybrid 614 as a late maturing variety. Global coupled model Hadley Centre Global Environment Model version 2 (HadGEM2-ES) under representative concentration pathways (RCP) 4.5 and 8.5 was used to downscale Nyando&rsquo;s climate data for the years 2030 and 2050. Past climate data for 53 years and current data was obtained from Kisumu Meteorological station while crop growth and farm management data was obtained from 70 farmers in Nyando. Results showed a decrease in yields across the years from 2015, 2030 and 2050 under both RCP 4.5 and 8.5. Average simulated yields for 2015 were 2519 kg ha-1 while projected yields under RCP 4.5 were 2212 and 2081 kg ha-1 in 2030 and 2050 respectively.&nbsp; Average yield projections under RCP 8.5 were 2184 and 1806 kg ha-1 for the years 2030 and 2050 consecutively. The study found out that temperatures will increase and rainfall duration will reduce. In addition, Katumani Comp B maize variety was not very much affected by these changes in temperatures and rainfall compared to H511 and H614.&nbsp; Key words: Climate change, Decision Support System for Agrotechnology Transfer (DSSAT), global coupled models, maize yield.