Effect of Plant Age at Harvest and Season on the Hydrocyanic Acid Potential of some Sorghum Cultivars Chaturvedi Vinod Kumar1, Devender Vishala Directorate of Sorghum Research, Rajendranagar, Hyderabad-500 030. (A.P.) India 1Author for correspondence: Central Plantation Crops Research Institute Regional Station, Krishnapuram P.O., Kayamkulam-690533Kerala e mail: vinodkumarchaturvedi827@gmail.com Phone No. 09288110929 Fax No. 0479 2445733
ABSTRACT The effect of harvesting at 30, 40, 50, 60, 70, 80 and 90 days after sowing (DAS) on the hydrocyanic acid potential (HCN-p) of two multicut (SSG-59-3 and X-988), two single cut (Pusa Chari-1 and IS 4776) and three dual purpose forage sorghum cultivars (CSV-10, Vidisha 60-1 and Chitta Jonna) was studied during kharif (rainy season 2005), rabi (post-rainy season 2005) and summer (2006) in pot experiments. The HCN-p tended to decrease with increase in plant age in all the seasons. HCN-p was lowest in Chitta Jonna in kharif, IS 4776 in rabi and SSG-59-3 in summer while it was highest in CSV-10 in all the seasons. The appropriate growth period for determining cultivar differences in HCN-p appeared to be 30 DAS in kharif and 40 DAS in both rabi and summer. At these plant ages in the respective seasons cultivar differences in HCN-p were prominent. Seasonal differences in HCN-p were significant and the highest was in summer followed by rabi and was lowest in kharif. Forage sorghum contained safe levels of HCNp (<200 ppm) at the recommended plant ages at harvest during kharif and rabi (45-60 DAS). Dual purpose sorghum also had safe levels of HCNp at the recommended plant ages at harvest for use as single cut forage during kharif and rabi seasons (60–90 DAS), with the exception of CSV-10, which had safe levels only at or after 80 DAS in rabi. But when summer grown, the safe plant age for harvesting the first cut of multicut sorghum was 60 DAS or later, whereas single cut and dual purpose sorghums, were not safe for feeding to cattle even up to 90 DAS in this season, with the exception of Chitta Jonna which showed safe levels at the recommended harvest stage. Top Keywords HCN, Sorghum, Forage, Plant age, Season. Top |