No abstract

The yield losses due to weeds vary depending on the weed species, their density and environmental factors. For controlling weeds in wheat, the farmers rely on herbicides due to cost and time effectiveness. Keeping these facts in view a field experiment was conducted to identify appropriate herbicides for controlling weeds in wheat. The experiment was carried out at three locations of Kapilvastu, Rupandehi and Nawalparasi during 2016/17 and 2017/18. Pendimethalin 30 EC, Sulfosulfuron 30 g a.i ha-1 and control treatments were evaluated in the field of six farmers in an area of 330 m2 for each treatment and were replicated six times. Wheat variety Tilottama was planted in the experiment. The fertilizer was applied at the rate of 100:50:50 N: P2O5: K2O kg ha-1. Weed populations were recorded at 30, 60 and 90 days after sowing in an area of 0.25 m-2 at three spots of each treatment and growth, yield attributes and yield data of wheat were collected and data were analyzed using Genstat statistical package. In 2016/17 Pendimethalin 1 kg a.i. ha-1 and Sulsosulfuron @ 25 g a.i. ha-1 and control (no herbicide spray) treatments were significantly difference for plant height, spike m-2 and grain yield but not significant for spike length and 1000 grains weight at Bimiha, Bhagdari and Nadawa sites.  Both herbicides were found effective in controlling weed population.  Whereas in 2017/18 Pendimethalin 30 EC. 1 kg a.i. ha-1 as pre-emergence and sulfosulfuron 30 g a.i. ha-1 as post emergence herbicides were found effective to suppress weed population. Plant height, spike length and 1000 grains weight variables were not significant but spikes m-2 and grains yield were significant Based on the pooled  results it could be concluded that Pendimethalin 1 kg a.i. ha-1 and Sulsosulfuron @ 25 g a.i. ha-1 herbicides were found effective in controlling weed population and increased yield attributes and yield in wheat crop over weedy check.

Field experiments were conducted during rainy seasons of 2017 and 2018 at National Wheat Research Program (NWRP), Bhairahawa to identify the suitable age and appropriate dose of digestate/biogas slurry regarding yield maximization of rice (cv. Ram dhan). The experiment compared the effect of different age [5 days (fresh), 90 days (3 months) and 180 days (6 months)] and dose (0, 5, 10 and 15 t ha-1) of digestate/biogas slurry on rice yield. The experiment was laid out in Randomized Complete Block design (RCBD) with three replications. Grain yield of rice was significantly higher (4.5 t ha-1) with the application of biogas slurry of 5 days than 90 days (4.3 t ha-1) age, in 2017 A. D. Similarly, yield was significantly higher (4.6 t ha-1) with the application of biogas slurry 5 days than of 90 days (4.5 t ha-1) age, in 2018.  Yield due to the application of biogas slurry of 5 days was equal to the yield resulted from the use of biogas slurry of 180 days in 2017 and 2018.  The pooled analysis showed that the yield with the application of biogas slurry of 5 days age was significantly higher (4.6 t ha-1) than the yield due to the application of biogas slurry of 90 (4. 4 t ha-1) and 180 days (4.5 t ha-1) age. The yield of rice has been found increasing significantly as the dose of biogas slurry was incremented from 0 t ha-1   to 15 t ha-1 in 2017, 2018 and in pooled analysis. The yield of rice was significantly higher (4.6 t ha-1)   in 2018 than in 2017 (4.4 t ha-1), in pooled analysis. Thus, the use of biogas slurry of the age of 5 days with the dose of 15 t ha-1 produced the  higher grain yield of rice.