Quality and yield response of soybean (Glycine max L. Merrill) to drought stress in sub–humid environment

The aim of the study was to determine the response of soybean [Glycine max (L.) Merr.] to drought at various stages of development in a sub-humid environment of Turkey. Drought-stress treatments was applied to plants in 2005 and 2006 by withholding irrigation at six critical stages: completely vegetative (fifth trifoliate) (T2), flowering (T3), podding (T4), seed fill (T5), full bloom + podding (T6), and podding + seed fill (T7). Growth and production was compared in each treatment to full irrigated (T1) and nonirrigated (T8) controls. Each drought treatment reduced shoot biomass and seed yield compared to wellwatered plants, but only  non-irrigated plants or plants droughted at vegetative or flowering stages produced fewer seed pods and seeds. Seed protein and oil content was highest among treatments when plants were droughted during the seed filling stage. Yield increased exponentially with crop water use and ranged from 2.1 - 2.5 tons haSup>-1 in non-irrigated plants to 3.5 - 4.0 tons ha-1 in the well-watered controls. However, plants droughted during the vegetative stage of development produced the highest yield per unit of irrigation water applied (that is,  irrigation water use efficiency). This research results will be useful for maximizing soybean production and/or seed quality when irrigation water is limited.Key words: Glycine max, flowering, irrigation, seed development, water use efficiency

Investigations on yield and quality characteristics of some oil rapeseed (brassica napus ssp. Oleifera) cultivars

Bu araştırma, Bursa bölgesinde kışlık tahıllarla ekim nöbetine girebilecek ve yağ üretimine katkıda bulunabilecek yüksek verimli ve kaliteli kışlık kolza.çeşitlerini saptamak amacıyla yapılmıştır. Denemede 5 adet yağlık kolza ve 1 adet yağ şalgamı çeşiti kullanılmıştır. Denemeler, kışlık ve yazlık olmak üzere 2 ayrı dönemde 3 tekerrürlü tesadüf blokları deseni içinde yürütülmüştür. Yazlık ekimde, aslında kışlık gelişme tabiatında olduğu bildirilen çeşitler gerekli soğuklanmayı alamadıkları için sapa kalkamamışlar ve çiçeklenememişlerdir. Denemede, çeşitlerin morfolojik ve fizyolojik özellikleri yanında verim ve verim komponentlerine ilişkin özellikler ile kalite Özellikleri üzerinde durulmuştur. Denemeye alman çeşitler arasında bitki boyu, yandal sayısı, sapa kalkma süresi ve çiçeklenme süresi bakımından önemli farklılıklar saptanmıştır. Bitki boyu bakımından en yüksek değer Si 6720/76 çeşitinde saptanırken yandal sayısı bakımından en yüksek değeri alan Rex çeşiti aynı zamanda en erken sapa kalkan ve çiçeklenen çeşit olma özelliğini de almıştır. Ana sap başına kapsül sayısı bakımından çeşitler arasında önemli bir farklılık olmadığı halde kapsül başına tane sayısı ve 1000 tane ağırlığı bakımından çeşitler arasındaki farklılık önemli çıkmıştır. Denemeye alınan çeşitler arasında tane verimi bakı mından ise önemli farklılıklar gözlenememiştir. Buna rağmen, en düşük verime sahip Si 6720/76 çeşiti ile en yüksek verime sahip. Chr. 1617/82 çeşiti arasında 40 kg'lık bir farklılık vardır, Chr. 1617/82 çeşiti 210 kg/da verim verirken, ikinci sırayı alan Rex çeşitinin verimi ise 198 kg/da olmuştur. Denemeye alınan tüm çeşitlerde yağ oranı % 40' m üzerinde bulunmuştur. Diğer yandan, bu çeşitlerde erusik asit sıfır düzeyindedir. Yağ asitleri kampozisyonu da yağ kalitesi yönünden ye terli düzeydedir. Sonuç olarak, denemeye alınan çeşitlerin yağ oranı ve yağ kalitesi yönünden oldukça yüksek düzeyde bulunduğunu söylemek mümkündür. Kolza, bölgemizde serin iklim tahılları yerine ikame olabilecek iyi bir münavebe bitkisidir. Tahıllardan daha önce olgunluca geldiği için ikinci ürün yetiştirme programlarında ön bitki olarak kullanılabilir. Özellikle, verimli çeşitlerin ekilmesiyle hem yağ üretimine katkıda bulunulmuş olacak, hem de yeni bir münavebe sistemi doğmuş olacaktır.This research, was caried out to determine the high yielding and quality winter rapeseed cultivars in order to use cereals-sun flower cropping system and to increase oil production in Bursa. The materyal of the research consisted of 1 turnip rape and 5 rapeseed varieties. The research was designed in randomized block design with 5 replications, in two different seeding time as winter and summer seeding. In this research morphologicial and bhysiological characte ristics of varieties, production and quality traits were examined. Significant differences between varieties in plant height, num ber of lateral branch, stem elongation and blooming time were noted. It was determined that Si 6720/76 variety was the tallest while Rex which had the most lateral branch was also the eafcliest in stem elon gation and blooming. Despite no difference between varieties in respect to the number of pod per main stem, there v/as a significant difference between varieties in number of grain per pod and the 1000-seed weight. There were no significant differences between varieties in seed yield but it was obtained 40 kg/da yield difference between the lowest (Si 6720/76) and the highest (Chr. 1617/82) yielding varieties. The seed yield of Chr. 1617/82 and Rex varieties were 210 kg/da and 198 kg/da, respectively. Oil percent of all varieties examined was higher than 40 % and the oil didn't contain erusic acid. The composi tion of oil acids was also suitable in oil quality. Due to it couldn't be met enough vernalization of the winter type varieties the stems arise and reach blooming stage in the summer seeding. In conclusion, it is possible to say that the oil content and its quality of all winter seeding plants tested in this research were considerably higher. Seemingly rapeseed will be one of the best rota tion crop to replace of cool season cereals in the region. Because of its earlier maturation than cereals rapeseed can be seeded as a main crop in two crop production system. Not only will it have been contributed to oil production but also a new rotation system will have been improved by sowing especially the productive rapeseed varie ties

Dry matter accumulation and forage quality characteristics of different soybean genotypes

Three different soybean [Glycine max(L.) Merr.] cultivars (A-3127, Derry, and Yemsoy) were evaluated for dry matter (DM) yield, plant components, and crop growth rate (CGR) at different row spacings and harvesting stages in 3 locations with Mediterranean- type climate in a split-split plot design with 3 replications in 2009 and 2010. In addition, crude protein (CP), crude protein yield (CPY), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and relative feed value (RFV) of harvested forage soybeans were determined at the Bursa (Turkey) location. Increased row spacings significantly reduced DM yield at all locations. Combined over other main effects, the 25-cm row spacing produced 35% more DM yield than the 75-cm row spacing. Row spacings greatly affected DM yield at the R5 and particularly the R7 stage, but this effect was minimal at the R1 stage. The forage-type cultivar Derry produced significantly higher DM yield in all locations, particularly at the R5 and R7 stages. The constituent components of DM were similar at different row spacings of soybean cultivars. In general, the CGR decreased from 25-cm row spacing to 75-cm row spacing in all locations, and the CGR of the cultivars varied significantly according to harvest period, row spacing, and location. Derry had a significantly higher CGR than the other cultivars in the Antalya and Bursa locations. Quality characteristics of soybean forage were not significantly affected by row spacing and showed little effect by cultivar. Harvest stage significantly affected CP, ADF, NDF, TDN, and RFV concentrations of soybean forage. It was concluded that in Mediterranean environments forage-type soybeans (i.e. Derry) can be seeded in narrow rows (25 cm) at high plant population (100 kg ha–1) and offer the most DM yield when harvested at later R stages (e.g., R7) rather than at the early reproductive stage.Three different soybean [Glycine max(L.) Merr.] cultivars (A-3127, Derry, and Yemsoy) were evaluated for dry matter (DM) yield, plant components, and crop growth rate (CGR) at different row spacings and harvesting stages in 3 locations with Mediterranean- type climate in a split-split plot design with 3 replications in 2009 and 2010. In addition, crude protein (CP), crude protein yield (CPY), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), and relative feed value (RFV) of harvested forage soybeans were determined at the Bursa (Turkey) location. Increased row spacings significantly reduced DM yield at all locations. Combined over other main effects, the 25-cm row spacing produced 35% more DM yield than the 75-cm row spacing. Row spacings greatly affected DM yield at the R5 and particularly the R7 stage, but this effect was minimal at the R1 stage. The forage-type cultivar Derry produced significantly higher DM yield in all locations, particularly at the R5 and R7 stages. The constituent components of DM were similar at different row spacings of soybean cultivars. In general, the CGR decreased from 25-cm row spacing to 75-cm row spacing in all locations, and the CGR of the cultivars varied significantly according to harvest period, row spacing, and location. Derry had a significantly higher CGR than the other cultivars in the Antalya and Bursa locations. Quality characteristics of soybean forage were not significantly affected by row spacing and showed little effect by cultivar. Harvest stage significantly affected CP, ADF, NDF, TDN, and RFV concentrations of soybean forage. It was concluded that in Mediterranean environments forage-type soybeans (i.e. Derry) can be seeded in narrow rows (25 cm) at high plant population (100 kg ha–1) and offer the most DM yield when harvested at later R stages (e.g., R7) rather than at the early reproductive stage