Nitrogen, sulphur and thiourea nutrition of pearl millet [Pennisetum glaucum (L.) R. Br.] - I. Effect on growth and dry matter production

Effects of nitrogen, sulphur and thiourea application on growth and dry matter production of pearl millet [Pennisetum glaucum (L.) R. Br.] were studied for three pears under arid conditions. On an average, 80 kg N ha(-1) was as good as 120 kg N ha(-1) but proved superior to 40 kg N ha(-1). Depending on the crop growth stage, N at 80 kg ha(-1) increased the plant height by 15.5 to 40.9% and number of green leaves by 17.1 to 37.0% over the control. Maximum leaf area index (LAI) of 3.5 was recorded with 80 kg N ha(-1) as against 2.4 in control plants at peak growth period (45 DAS). Nitrogen application also significantly increased number of tillers and dry matter accumulations. The improvements in crop grow th were reflected in increased net assimilation rate (NAR) and crop growth rate (CGR) at 45 and 60 DAS. Soil application of sulphur did not significantly improve anp of the growth parameters, inspite of the low availability of S in soil (<10 ppm), indicating presence of efficient sulphur uptake aid translocation mechanisms in pearl millet. Thiourea, seed plus foliar, treatment increased the plant height by 5.7, 7.5 and 9.9 cm over untreated control at 45, 60, and 75 DAS, respectively. The increase in number of green leaves plant(-1) was between 0.9 and 2.6 which increased the LAI by 0.1-0.2 at various growth stages. Additional gain in dry matter accumulation due to thiourea over untreated control ranged between 1.6-1.7 g plant(-1). The NAR improved from 4.8 g m(-2) day(-1) under untreated to 5.4 g m(-2) d(-1) with thiourea treatment at 45 DAS. Corresponding improvement hi CGR was from 9.9 g m(-2) day(-1) to 11.4 g m(-2) day(-1). Delayed leaf ageing, slower senescence and increased photosynthetic efficiency led to enhanced growth due to thiourea treatment.