Integrating cover crops into farming systems may contribute to meeting N demands of succeeding crops and therefore decrease fertilization and environmental concerns. To study the trend of released N in buried (BR) and surface residues (SR) of three different cover crops a 2‐yr field experiment was conducted in a randomized complete block design on a fine sandy loam. Forage radish (Raphanus sativus L.) and winter pea (Pisum sativum subsp. arvense L.) decomposition rate and N release trend were compared with cereal rye (Secale cereale L.), as the conventionally grown cover crop in Massachusetts, to evaluate if forage radish or winter pea would provide more N for early planted crops in the spring than cereal rye. Forage radish produced the highest dry matter yield (3.46 Mg ha−1) followed by winter pea (3.1 Mg ha−1) and cereal rye (2.42 Mg ha−1). All of the cover crops had a faster residue decomposition and release of N when buried in the soil. Through the decomposition period, forage radish and winter pea lost their initial biomass and N concentration faster than cereal rye in both BR and SR due to higher C/N ratio and lignin concentration in rye. Our results showed a greater potential of forage radish or winter pea for a synchronous N release relative to crop N demands early in the spring than with cereal rye.Core Ideas Forage radish has great potential for synchronous N release with cash crop N demands early in the spring. A high N yielding winterkilled cover crop is preferred over rye if early planting of cash crop is target. Rye may not provide the succeeding crop with sufficient N when terminated early.

Six modern varieties of potatoes (Diamant, Cardinal, Granola, Felsina, Provento and Asterix) were investigated for their growth parameters and yield to determine their suitability for production in Bangladesh. Results indicate significant variations among the varieties in the yield and morphological characteristics and no difference in the number of main stems per hill. Among the six studied varieties, Asterix produced the greatest yield (29.60 t/ha), the greatest number of tubers per hill (13 tubers/hill), the largest percentage (84%) of medium sized tubers (28 -55 mm diameter), and the greatest plant height (61.33 cm). Diamant performed second after Asterix with a yield of 28.33 t/ha, and a plant height of 59.0 cm. Felsina produced the lowest yield (25.13 t/ha) and the lowest number of tubers per hill (8.67 tubers/hill). In a farmers' perception study, where farmers scored the yield and resistance to diseases and insect damage of the six varieties, from 1 to 6 (6 being the highest and 1 being the lowest), Asterix was the most preferred variety by farmers with scores of 6, 5.67 and 5.83 for yield, disease resistance and insect resistance respectively. Provento was the least preferred by farmers with a score of overall performance of 4. The results of this study indicate that Asterix and Diamant have the potential to be grown successfully by the farmers in Bangladesh.

No abstract

The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contributing traits. Spring wheat cultivar of 25 genotypes were selected and cultivated under late sowing condition at the Regional Wheat Research Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017. Significant variability among the genotypes exposed for different traits related to heat tolerance. Results showed that the genotypes G24, G10, G01, G13, G16, G25 and G14 ranked as better category considering maximum number of traits in mean performance indicating their tolerance to heat stress under late sowing condition. Phenotypic variances ( 2 p σ ) of all traits were greater than those of genotypic variances ( 2 g σ ). The same trends were also found in their co-efficient of variances. The phenotypic co-efficient of variances (PCV) of all traits were greater compare to those of genotypic co-efficient of variances (GCV) and their values were closer to each other. The heading days (HD), canopy temperature at vegetative stage (CT vg ), canopy temperature at grain filling stage (CT gf ), biomass, plant height (PH), spike/m 2 (SPM), spikelet/spike (SPS), grain/ spike (GPS), thousand grain weight (TGW) and yield exhibited higher heritability ( 2 b h ) estimated under irrigated late sowing (ILS) condition. Under the same ILS condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic advance (GA) obtained through computing their mean percentage (%) and the rest traits HD, maturity days (MD), CT vg , CT gf , biomass, PH and harvest index (HI) exposed smaller genetic advance (% mean).

No abstract