PERFORMANCE OF SWEET CORN HYBRID UNDER DIFFERENT LEVELS OF IRRIGATION AND NITROGEN APPLIED THROUGH DRIP SYSTEM

A field experiment was conducted at Maize Research Station, AICMIP, Agricultural Research Institute, Acharya N. G. Ranga Agricultural University, Rajendranagar, Hyderabad during rabi 2011-12 to study the “Performance of sweet corn hybrid under different levels of irrigation and nitrogen applied through drip system”. The experiment was laid out in a factorial RBD with combinations of five Irrigation levels viz., I1 Drip irrigation at 60% Epan, I2 Drip irrigation at 80% Epan, I3 Drip irrigation at 100% Epan, I4 Drip irrigation at 120% Epan and I5 – Ridge and furrow/surface irrigation at 1.0 IW/CPE and four N fertigation levels viz., N1-120 Kg ha, N2-160 Kg ha , N3-200 Kg ha and N4240 kg ha and was replicated thrice. Sweet corn hybrid HSC-1(Haryana sweet corn-1) was sown on 15-11-2011 at a spacing of 60 x 20 cm with one seed hill. 60 kg P2O5 and 50 kg K2O ha were applied in the form of SSP and MOP as basal to all the treatments. The experimental soil was clay loam with low in available nitrogen, medium in available phosphorus and potassium. The irrigation and fertigation treatments were scheduled once in two days and six days respectively as per the treatments. The mean maximum and minimum temperature were 30.8c and 14.4c respectively during crop growth period. No rainfall was received during experimental period. The mean bulk density and available soil moisture in 60 cm depth of soil was 1.417 g cm and 121.28 mm respectively. Plant height LAI and dry matter production were not influenced by drip irrigation and N fertigation levels at 20 DAS. The maximum plant height, LAI and dry matter production were recorded with drip irrigation scheduled at 120% Epan at 40, 60 DAS and at harvest and statistically on par with 100% Epan. Among the nitrogen levels, application of N at 240 kg ha recorded maximum plant height, LAI and dry matter production and it was on par with 200 kg N ha but significantly superior over other treatments. The interaction effect of treatments was not significant on plant height and LAI at all crop growth stages whereas dry matter production was significantly influenced by interaction of treatments at 60 DAS and at harvest. Dry matter production was higher at drip irrigation level of 120% Epan along with 240 kg ha(I4N4) and was at par with I4N3, I3N4 and I3N3. The leaf stem ratio was significantly influenced due to irrigation and nitrogen levels at all the growth stages. Maximum leaf stem ratio was registered with drip at 120% Epan it was statistically on par with 100% Epan. Each increment of N level from 120 kg ha to 240 kg ha significantly influenced leaf stem ratio at 20 and 40 DAS reaching a maximum at 240 kg ha but it was on par with 200 kg N ha at 60 DAS and at harvest. The less number of days to reach 50 per cent tasseling and silking was recorded with drip irrigation scheduled at 120% Epan and 100% Epan. Application of 200 and 240 kg N ha took same number of days to reach 50 per cent tasseling and silking. Yield attributes viz., cob length, fresh cob weight, number of kernels per row, number of cobs per plant and test weight were significantly higher by scheduling drip irrigation at 120% Epan and it was on par with drip at 100% Epan but superior over other treatments. Each increment in N levels significantly increased all these attributes up to 200 kg ha. Cob girth was maximum with drip irrigation scheduled at 120% E pan and it was on par with 80 and 100% Epan. Cob girth recorded at 240 kg N ha was higher and it was on par with 160 and 200 kg N ha. Interaction between Irrigation and nitrogen levels was not significant on these attributes except number of cobs plant The response of sweet corn to drip-fertigation was found superior in terms of green cob yield and fodder yield. Maximum green cob yield and fodder yield were recorded with drip irrigation scheduled at 120% Epan followed by 100% Epan and both were significantly superior from remaining levels of irrigation. Lowest yield was recorded with surface irrigation at 1.0 IW/CPE ratio. All the drip irrigation levels were significantly superior over surface method of irrigation. Among the nitrogen levels, application of 240 kg N ha was recorded maximum green cob yield and fodder yield which was on par with 200 kg N ha and both were significantly differed from remaining dose of nitrogen levels. Minimum green cob and fodder yield were recorded at 120 kg N ha.The interaction effect between drip irrigation scheduling and N fertigation levels showed that significantly higher green cob yield and fodder yield were obtained with drip irrigation at 120% Epan and N fertigation of 240 ka ha(I4N4) but drip at 120% and 100% Epan along with application of 240 and 200 kg N ha recorded on par results but significantly superior from other treatments. Crude protein content of sweet corn kernels was superior with drip at 120% Epan and 100% Epan. Application of nitrogen levels of 240 and 200 kg ha recorded on par results but superior performance over other treatments. Sucrose content of sweet corn was significantly influenced by nitrogen levels only and it increased with increase in levels of nitrogen from 120 to 240 kg ha. Application of 240 kg N ha recorded maximum per cent of sucrose in the grain but it was found on par with 200 kg N ha. Maximum uptake of nutrients (N, P and K) at harvest was observed with drip irrigation scheduled at 120% Epan and was on par with drip irrigation scheduled at 100% Epan while in case of nitrogen levels, significantly higher uptake was obtained with application of 240 kg N hafollowed by 200 kg N ha and superior over remaining treatments. Influence of varying irrigation and nitrogen levels on nutrient status of soil at harvest showed significant difference for available nitrogen only. Maximum availability of N was noticed in drip irrigation schedule at 100% E pan followed by 120% E pan and both were at par. Available nitrogen content of soil increased with higher doses of nitrogen (240 kg N ha) however it was on par with 200 kg N ha. Irrigation scheduling through drip at 120% Epan resulted in higher crop coefficient value (Kc) at 20, 40, 60 DAS and at harvest. Kc values increased linearly with advancement of crop life, attained peak values at mid season stage and decreased towards late season stage. The seasonal crop ETa was highest in drip at 120% Epan followed by 100% Epan. Highest field water use efficiency (FWUE) efficiency was recorded with drip at 60% Epan followed by drip at 80%, 100% and 120% Epan respectively. Crop water use efficiency was significantly higher with drip irrigation scheduled at 60% Epan. However, Drip at 80%, 100% and 120% Epan recorded on par results of crop water use efficiency but significantly superior to surface irrigation scheduled at 1.0 IW/CPE. Crop water use efficiency increased with increase in N levels reaching a maximum at 240 and 200 kg ha respectively. The economics of sweet corn hybrid as influenced by drip irrigation and N fertigation revealed that the highest net returns (Rs.57266 ha) were obtained with drip irrigation scheduled at 120% Epan followed by 100% Epan. Regarding the nitrogen levels, highest net returns (Rs.50342 ha) were obtained with 240 kg N ha followed by 200 kg ha. Higher B: C ratio (2.6) was obtained with drip irrigation scheduled at 120% Epan and 100% Epan and the lowest (1.5) was recorded with surface irrigation. Among the nitrogen levels, the highest B: C ratio (2.4) was obtained with 240 kg N ha and 200 kg N ha. The lowest B:C ratio was with 120 kg N ha (1.8). It can be concluded that for maximizing production of sweet corn, drip irrigation scheduling at 100% Epan and N fertigation at 200 Kg ha can be recommended in semiarid climate of Andhra Pradesh.