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ThesisItem Open Access Standardisation of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)].(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ajmal Fayique, C; KAU; Usha C, ThomasThe study entitled “Standardization of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)]” was conducted at College of Agriculture, Vellayani, Kerala during Kharif 2017 to standardize the spacing and nutrient requirement of fodder rice bean and to study its impact on growth, yield and quality of the crop. The experiment was laid out in Randomised Block Design (33 confounded factorial) with three replications.The treatments consisted of three spacings (s1 - 30 cm x 10 cm, s2 - 30 cm x 20 cm and s3 - 30 cm x 30 cm), three levels of nitrogen (n0 - 0 kg ha-1, n1 - 20 kg ha-1 and n2 - 30 kg ha-1) and three levels of phosphorous (p0 - 0 kg P2O5 ha-1, p1 - 20 kg P2O5 ha-1 and p2 - 40 kg P2O5 ha-1) . FYM @ 5 t ha-1 and K2O @ 30 kg ha-1 were applied uniformly to all treatments as basal. The treatment s1 resulted in the highest plant height at 30 DAS and leaf: stem ratio at harvest. Application of N @ 20 kg ha-1 registered the highest plant height and was on par with 30 kg N (n2) while leaf stem ratio was the highest at n2. Levels of P had no significant impact on growth characters. The treatment combination s2n2p1 produced the tallest plants (173.17 cm) at harvest and treatments s1n0p1 and s1n2p2 recorded the highest leaf: stem ratio (0.82) but were on par with s1n0p0, s2n0p0, s n0p2, s1n1p0, s2n0p2 and s3n0p1. At 30 DAS, s1 produced the highest LAI (2.27) while at harvest, s2 was found superior. The highest NAR was observed at s1 and was on par with s3. Closer spacing (s1) enhanced the CGR at 30 DAS and harvest. Application of 30 kg N ha-1 (n2) enhanced LAI at both stages. At 30 DAS and at harvest, higher NAR were observed at n1 and n2. At 30 DAS, n2 and p1 registered the highest chlorophyll contents. The treatment s1 n2 p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1) resulted in the highest LAI, CGR and chlorophyll content at 30 DAS. Spacing and N levels had significant impact on green fodder yield (GFY) and dry fodder yield (DFY). The highest GFY (12.95 t ha-1) and DFY (2.59 t ha-1) were produced at s1 (30 cm x 10 cm) and was on par with s2. The highest GFY (13.66 t ha-1) and DFY (2.73 t ha-1) were produced at n2 (30 kg N ha-1) and was on par with n1. The S x N x P interaction s1 n2 p1 (30 cm x 10 cm + 30 kg N ha-1 + 20 kg P2O5 ha-1) recorded highest GFY (17.29 t ha-1) and DFY (3.46 t ha-1). The different spacing had no impact on crude protein (CP) but the lowest crude fibre (CF) was observed at s1. Application of 30 kg N ha-1 (n2) resulted in the highest CP content and the lowest CF content was estimated at 0 kg N ha-1. Among P levels, p2 recorded the highest CP (17.69%) and was on par with p1. The lowest CF (16.43 %) was observed at s2n0p1 (30 cm x 20 cm spacing + 20 kg P205 ha-1) and was on par with s1n0p0, s1n0p1, s1n2p0, s2n0p0, s2n0p2, s3n0p0 and s3n0p1. No variation in N uptake was observed due to treatments. Uptake of P varied with N levels only and n1 and n2 recorded the highest P uptake. Spacing and P levels influenced K uptake by the crop and the highest uptake was observed at s1 and p2 but p2 was on par with p1. The three factor interaction s1n2p1 registered the highest P and K uptake. However, it was on par with s1n1p2, s1n1p0, s2n1p1 and s3n0p2 in P uptake and with s1n2p2 in K uptake. Increasing N levels increased pH and EC of soil after the experiment. Soil available N after the experiment was the highest at s3 (on par with s2) and n2 (on par with n1). At wider spacing, application of N enhanced the availability of N in the soil after the experiment. Available P in the soil varied with S x P interaction but all treatment combinations were on par except s2p0 and s3p2. The highest soil available K was observed at n0 among N levels and at p1 among P levels. The interactions S x N, S x P and N x P significantly influenced available K in the soil. Economic analysis revealed the highest net income (₹ 35762) and BC ratio (3.22) at s1n2p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1). From the study, it can be concluded that fodder rice bean can be profitably cultivated at a spacing of 30 cm x 10 cm with application of 30 kg N ha -1 in two splits at 15 and 30 DAS and basal application of 20 kg P2O5 ha-1, 5 t ha-1 of FYM and 30 kg K2O ha-1.ThesisItem Open Access Response of sweet potato [Ipomoea batatas (L.) Lam.] to secondary nutrients(Department of Agronomy, College of Horticulture, Vellanikkara, 2020) Nengparmoi, TH; KAU; Prameela, PSweet potato is an important food crop with short duration and high nutrient requirement. As the deficiency of secondary nutrients is generally encountered in highly leached acid soils of Kerala and the research on supplementation of these nutrients in enhancing the productivity of sweet potato is limited, the present study entitled “Response of sweet potato [Ipomoea batatas (L.) Lam.] to secondary nutrients” was carried out. The objective was to assess the influence of secondary nutrients on growth, yield and quality of sweetpotato. The experiment was conducted from September 2019 to January 2020 at Agronomy Farm, College of Horticulture, Vellanikkara, Thrissur. The experiment was laid out in RBD with 11 treatments replicated thrice. The treatments included five levels of magnesium sulphate i.e., 0, 40, 60, 80 and 100 kg/ha along with N: P2O5 : K2O @ 75:50:75 kg/ha (KAU POP) and N : P2O5 : K2O @ 65:12:20 (soil test based). A high yielding sweet potato variety ‘Sree Kanaka’ was used. Growth parameters like vine length, leaf area, and total dry matter accumulation per plant were significantly influenced by nutrient management. Higher doses of N: P2O5 : K2O (75:50:75) irrespective of MgSO4 dose (0 to 100 kg/ha) showed higher values for these parameters compared to treatments receiving lower doses of N : P2O5 : K2O (65:12:20) along with MgSO4. At 30 days after planting (DAP), vine length ranged from 40.5 cm to 55.6 cm and it increased to 2.5m by 90 DAP. At this stage, all the treatments exhibited comparable vine length irrespective of nutrient doses, except T3 (65:12:20 + MgSO4 @ 60 kg/ha) and T7 (75:50:75 + MgSO4 @ 40 kg/ha) which registered higher values and differed significantly from others. Higher and comparable total dry matter accumulation was also observed in treatments where N : P2O5 : K2O @ 75:50:75 along with varying doses of MgSO4 was applied. The highest leaf area index of 3.48 was noticed in treatment T8 which received N : P2O5 : K2O (75:50:75) with MgSO4 @ 60 kg/ha and the lowest was seen in organic management (T11). Chlorophyll content at 60 DAP was not significantly influenced by varied doses of nutrients applied. Marketable tuber yield ranged from 19.8 to 35.9 t/ha and the treatments T7 (75:50:75 + MgSO4 @ 40 kg/ha) (35.9 t/ha) and T11 (organic management) (32.2 t/ha) resulted in higher tuber yields and were on par. Application of lower dose of N: P2O5: K2O based on soil test values resulted in lower yields compared to recommended dose. The highest harvest index of 0.72 was observed in T11 (Organic management) followed by T7 (0.60). Unmarketable tuber yield ranged from 1.0 to 1.7 t/ha. Higher and comparable unmarketable yield was observed in treatments T2 (65:12:20 + MgSO4 @ 40 kg/ha) and T3 (65:12:20 + MgSO4 @ 60 kg/ha) which received lower doses of N : P2O5 : K2O and MgSO4 and registered lower marketable yield. The unmarketable yield was the lowest in superior treatment T7 (75:50:75 + MgSO4 @ 40 kg/ha). Quality parameters of sweet potato tuber i.e. total, reducing and non-reducing sugar, crude fibre and crude protein were also estimated. In general, higher and comparable reducing sugar and total sugar content was observed in treatments which received higher doses of N : P2O5 : K2O and in tubers from organic nutrient management. Content of non-reducing sugar, crude fibre and crude protein did not vary significantly and the average values were 6.7, 2.6 and 14.3 % respectively. The soil chemical parameters in post-harvest soil showed a decline in pH and EC except in organic management where an increase in soil pH could be observed. The organic carbon was influenced by nutrient management however, it was in medium range in all the treatments. The average N, P and K uptake by sweet potato was 281, 10 and 156 kg/ha respectively, and the corresponding values for calcium, magnesium and sulphur were 20, 13 and 17 kg/ha respectively. Application of recommended dose of N : P2O5 : K2O along with 40 kg/ha magnesium sulphate resulted in the highest gross return (Rs. 5,38,500), net return (Rs. 4,05,619) as well as B:C ratio (4.1). Organic nutrient management system was the next best treatment with a net return of Rs. 2,88,050 and B:C ratio of 2.5. Hence N : P2O5 : K2O @ 75:50:75 along with 40 kg/ha of magnesium sulphate can be recommended in soils deficient in Mg for enhancing productivity of sweet potato. The results also indicate that organic nutrient management also will be economically viable in sweet potato production if premium price can be assured for the produce.ThesisItem Open Access Chemical Priming for improving salinity tolerance in rice(Department of Agronomy, College of Agriculture, Vellanikkara, 2020) Liz J, Kappen; KAU; Deepa, ThomasMeasures to improve abiotic stress tolerance in plants is gaining importance due to raised concerns on climate change and food security issues all over the world. Though different methodologies for combating abiotic stress like conventional breeding and molecular breeding have been in existence, they are often limited by time and biosafety concerns respectively. Chemical priming is a cost-effective approach in managing abiotic stress. It is reported that use of chemicals, both synthetic and natural, prior to stress events can enhance tolerance to abiotic stresses such as salinity and drought. Application of chemical agents externally can impart a minor stress which will help to generate stress signals that can lead to certain biological changes resulting in increased stress tolerance in later stages of the crop. Rice is a crop badly affected by salinity. Use of chemicals such as beta amino butyric acid (BABA), sodium nitroprusside and calcium chloride as seed primers to improve salinity tolerance may turn promising. With this objective a study was formulated with three experiments. The experiments were screening rice varieties for salinity tolerance, effect of seed priming on germination of rice varieties under salt stress condition and field trial to assess the effect of priming in rice fields with saline water intrusion. The First experiment was a lab study to screen three rice varieties namely Jyothi, Uma and Vytilla-10 at five salinity levels i.e., non-saline, 3 dS/m, 6 dS/m, 9 dS/m and 12 dS/m. Based on the results it was concluded that at 16 DAS with salinity level of 6 dS/m variety Vytilla-10 was highly tolerant (score 1). Variety Jyothi was found susceptible at 6 dS/m (score 7) whereas variety Uma was moderately tolerant (with score 5). At 21 DAS, varieties Uma and Vytilla-10 were found to be susceptible at salinity levels of 6 and 9 dS/m respectively with a score of 7. Objective of second experiment was to assess whether chemical priming could improve salinity threshold of the three varieties. The design used was two factorial CRD with three replications. The treatments were four priming chemicals and two salinity levels. Based on the results of the first experiment, threshold salinity level for Jyothi, Uma and Vtyilla-10 were estimated. Jyothi and Uma were susceptible at 6 dS/m, while Vytilla-10 was susceptible at 9 dS/m. Therefore, in second experiment variety Jyothi, salinity levels of 6 dS/m and 9 dS/m, for variety Uma salinity levels of 6 dS/m and 9 dS/m and for Vytilla-10 salinity levels 9 dS/m and 12 dS/m were taken. Each variety was primed using three chemicals, namely beta amino butyric acid (BABA 1 Mm/L), sodium nitroprusside (SNP,100 μM) and calcium chloride (CaCl2, 2%), water priming was included as control. The efficacy of each priming chemical was analyzed based on germination percentage, growth parameters and visual salt injury symptoms. Priming seeds with calcium chloride was found to influence both the growth parameters and salinity tolerance of seedlings. Based on the results of second experiment, a field trial was undertaken to assess the efficacy of priming chemicals as seed primers and as foliar spray. An experiment was laid out at Rice Research Station, Vytilla in factorial RBD with three replications. The treatments were three priming chemicals namely beta amino butyric acid (BABA), sodium nitroprusside (SNP) and calcium chloride (CaCl2), with water priming as control and three foliar sprays at weekly intervals, fortnightly intervals and weekly water spray. Rice variety Vytilla-10 was used for the study. The seedlings were transplanted to main field and foliar spraying of priming chemicals was done at weekly intervals at 30, 37 and 45 DAS, fortnightly intervals at 30, 45 and 60 DAS as well as weekly water spray. Calcium chloride seed priming was found effective in increasing plant height at 60 DAT, leaf area index, number of panicles, percentage of filled grains, thousand grain weight, yield, proline content in leaf and chlorophyll content (at 60 DAT). Most of the growth and yield parameters were influenced by weekly spray of calcium chloride. More tillers/m2 was observed in seedlings primed using SNP and weekly foliar spraying of SNP was effective in increasing tillering. Total chlorophyll content was found to increase with SNP seed priming and foliar spraying of SNP at fortnightly intervals was found most effective at 60 DAT to increase chlorophyll content. Grain filling was found to increase with BABA seed priming and weekly foliar spray of the same chemical was highly effective. Priming rice seeds with 2 % calcium chloride and foliar spraying of calcium chloride at 2 % on a weekly basis was found to be a reliable method to combat salinity stress and for improving growth, yield and yield attributes of rice.ThesisItem Open Access Perfomance of high yielding varieties of finger millet [Eleusine coracana (L.)] (Gaertn)(Department of Agronomy, College of Agriculture, Vellanikkara, 2020) Kishore, Neeruganti; KAU; Prameela, PAn experiment entitled “Performance of high yielding varieties of finger millet (Eleusine coracana (L.) Gaertn)” was undertaken during the period from July 2018 to January2019 at the Agronomy Farm, College of Agriculture, Vellanikkara, Thrissur.The objective of the experiment was to evaluate the performance of some prominent high yielding varieties of ragi suitable for Kharif and Rabi seasons in central Kerala. Randomized block design was adopted with nine varieties and three replications in both seasons. The plot size was 5 m x 4 m and the seeds were line sown at a spacing of 25 cm x 15 cm. The high yielding varieties included were VR 708 (Champavathi), Vakula, Hima, Maruthi and PR 202 (Godavari) (released from Andhra Pradesh), GPU 48, GPU 28 and KMR 201 (released from Karnataka) and Co15 (released from Tamil Nadu). All the management practices were done as per Package of Practices Recommendations of KAU. Observations on growth parameters were taken at 30 DAS, flowering and at harvest. Quality parameters of grain (crude protein, crude fibre, Ca and Fe), yield and yield attributes were also recorded. Varietal differences were significant with respect to plant height. In Kharif, when plant height was recorded at harvesting, GPU 28 (109.71 cm) and PR 202 (111.07 cm) were superior to all other varieties with statistically comparable values. The shorter varieties were GPU 48 (77.75 cm) and VR 708 (78.39 cm). At this stage in Rabi, CO15 had the tallest plants (100.41 cm). However, PR 202 also had statistically comparable plant height (98.65 cm). VR 708, Maruthi and GPU 48 were statistically on par and were inferior to other varieties with plant height in the range 72.17cm to 73.99cm. The varieties differed significantly with respect to total number of tillers in both the seasons. In general, Rabi crop had a greater number of basal tillers than the Kharif crop. The average number of basal tillers was 5.80 in Kharif and 6.80 in Rabi. In Kharif, variety VR 708 (9.27) was statistically superior with respect to basal tillers produced than other varieties. Variety Vakula produced only 3.6 tillers per plant. In Rabi, the greater number of tillers were produced by VR 708 (10.27) and CO15 (9.93). Total number of tillers showed an increase in most of the varieties, and in Hima and Vakula, a sharp increase in tiller number during Rabi was registered compared to Kharif. Seasonal differences were not pronounced in many varieties with respect to days to flowering but variation to the extent of up to 11 days was noticed in variety GPU 28. On an average, the days to 50 per cent flowering was 69 in Kharif and 72 in Rabi season. In Kharif season, PR 202 took the longest period for 50 percent flowering (79 days). The calcium content in ragi grain showed wide variability among varieties ranging from 326mg/100g to 564 mg/100g over the seasons and Fe content was in a narrow range of 6.25 – 8.91 mg/100g. There was no significant difference in fibre content of various varieties. More productive tillers were produced by CO15 and the minimum number of productive tillers were produced by Maruthi. Wide variations in finger length was observed among varieties and the values ranged from 5.30cm to 11.87 cm in Kharif and 6.23 to 11.97 cm in Rabi season. Vakula had the highest value in both seasons and was significantly superior to all others. The test weight ranged from 1.53 to 3.53 g in Kharif and from 1.51 to 3.25 g in Rabi among the varieties. Variety PR 202 had the highest 1000 grain weight of 3.53g. The average straw yield was 3592 kg/ha in Kharif whereas a higher value of 4010 kg/ha was realized in Rabi. The highest straw yield was for KMR 201(5100 kg/ha & 5141 kg/ha in Kharif and Rabi)) which was on par with GPU 48 (4578 kg/ha) in Kharif. The straw yields were low in Maruthi (3059.7 kg/ha), Vakula (3388.8 kg/ha) and VR 708 (3550 kg/ha) in both seasons. Among the nine varieties tried, six varieties - GPU 48, GPU 28, Hima, CO15 , PR 202 (Godavari) and KMR 201 performed better in Kharif as well as in Rabi season. The variety KMR 201 was found to be superior in terms of yield in both the seasons (3008.3 and 2737 kg/ha, respectively), whereas the white seeded variety Hima was found to be ideal for Rabi season due to its superior yield of 3092 kg/ha . Variety CO15 showed more adaptability to Kharif with grain yield of 2355 kg/ha and the performance was poor in Rabi (1833.33 kg/ha). Three varieties VR 708, Vakula and Maruthi are not ideal varieties for Kerala especially for Kharif seasonThesisItem Open Access Weed management for upland rice(Department of Agronomy, College of Horticulture, Vellanikkara, 2020) Basila, Y; KAU; Anitha, SRice is one of the principal food crops in Asia and can be grown in wetland and upland conditions. Upland rice is grown in rainfed, naturally well drained soils with bunded or unbunded fields without surface water accumulation. Moisture stress, weed infestation, poor soil fertility and incidence of pests and diseases are major problems in upland rice cultivation. Among these, weeds are considered to be most serious. Hence an effective and timely control of weed is essential to achieve higher productivity in upland rice. Field experiment was conducted at Agronomy Farm, College of Horticulture, Vellanikkara from June 2019 to September 2019 to develop cost effective weed management strategy for upland rice. The experiment was laid out in RBD with eight treatments and three replications. Treatments were T₁: Brown manuring (Cowpea) by application of 2,4-D on 25 DAS, T₂: In situ green manuring (Cowpea), on 25 DAS, T₃: Oxyfluorfen on the day of sowing fb HW at 30 DAS, T₄: Oxyfluorfen on the day of sowing fb bispyribac sodium on 20 DAS, T₅: Pyrazosulfuron on 6 DAS fb HW at 30 DAS, T₆: Pyrazosulfuron ethyl on 6 DAS fb bispyribac sodium on 20 DAS, T₇: Hand weeded control and T₈: Unweeded control. Dominant grass weed species observed were Echinochloa colona, Digitaria sanguinalis, Eleusine indica, Panicum maximum, Setaria spp, and Brachiaria spp. Dominant broad-leaf weed species were Alternanthera bettzickiana, Mitracarpus hirtus, Euphorbia hirta, Euphorbia geniculata, Ludwigia perennis, Scoparia dulcis, Ageratum conyzoides, Phyllanthus amara, Cleome burmannii, Commelina benghalensis, Lindernia crustacea, Catharanthus pusillus, Trianthema portulacastrum, Mollugo disticha and Hemidesmus indicus. Cyperus iria was the only sedge observed in the experimental field. Lowest weed dry matter production was recorded in hand-weeded control at 20 and 45 DAS. Application of oxyfluorfen fb HW at 30 DAS was as effective as hand weeded control and resulted in lesser weed count, weed dry matter, weed index and high weed control efficiency. Application of oxyfluorfen fb HW at 30 DAS resulted in maximum WCE of 92.60 % at 20 DAS and 98.58 % at 45 DAS. Lowest weed index was resulted from oxyfluorfen fb HW at 30 DAS (5.02 %) and was on par with pyrazosulfuron-ethyl on 6 DAS fb HW at 30 DAS (10.35 %). In situ green manuring and brown manuring resulted in significant reduction in weed dry matter production and high WCE at early stages of crop growth as compared to unweeded control, but it was not as effective as herbicide application. Application of oxyfluorfen fb HW at 30 DAS resulted in highest number of tillers per hill, leaf area index and number of hills/m². Hand-weeded control resulted in significantly higher grain yield (2888 kg/ha) and was on par with application of oxyfluorfen fb HW at 30 DAS (2743 kg/ha) and pyrazosulfuron-ethyl fb HW at 30 DAS (2589 kg/ha). Weed competition resulted in 78.05 % yield reduction in upland rice. Oxyfluorfen fb HW at 30 DAS resulted in highest straw yield (5898 kg/ha), which was on par with pyrazosulfuron-ethyl fb HW at 30 DAS (5886 kg/ha) and hand-weeded control (5415 kg/ha). Unweeded control resulted in significantly lower grain yield (634 kg/ha) and straw yield (943 kg/ha). Application of oxyfluorfen fb HW at 30 DAS resulted in higher N uptake by rice at all stages of observation and higher P uptake at harvest. At 30 DAS, application of pyrazosulfuron-ethyl fb bispyribac sodium resulted in higher P and K uptake by rice. At 60 DAS, the treatment brown manuring resulted in higher P uptake and application of oxyfluorfen fb bispyribac sodium resulted in higher K uptake by rice. At harvest, application of pyrazosulfuron-ethyl fb HW at 30 DAS resulted in higher K uptake by rice. Less N, P and K removal by weeds was observed in treatments oxyfluorfen fb HW at 30 DAS and hand-weeded control. Brown manuring resulted in higher organic carbon and soil microbial biomass carbon. Higher soil N and P availability was recorded in plots sprayed with oxyfluorfen fb bispyribac sodium and higher soil K availability was in pyrazosulfuron-ethyl on 6 DAS fb HW at 30 DAS. Application of oxyfluorfen 23.5 EC @ 0.15 kg/ha on the day of sowing fb HW at 30 DAS resulted in higher gross return, net return and B: C ratio, which was on par with pyrazosulfuron-ethyl 10 WP @ 0.03 kg/ha on 6 DAS fb hand weeding at 30 DAS. Hence, either of these pre-emergence herbicides followed by one hand weeding at 30 DAS can be recommended for a cost effective weed management in upland rice.ThesisItem Open Access Micronutrient management of sweet corn (Zea mays var. saccharata) hybrids for yield and quality(Department of Agronomy, College of Agriculture, Padannakkad, 2020) Deepa Mary, Varghese.; KAU; Vandana, VenugopalAn investigation entitled “Micronutrient management of sweet corn (Zea mays var. saccharata) hybrids for yield and quality” was undertaken with the objectives to evaluate the performance of sweet corn hybrids for yield and quality and to study the role of zinc and boron in increasing the productivity, quality and profitability of the crop. The study was carried out at College of Agriculture, Padannakkad and Regional Agricultural Research Station, Pilicode during 2019-2020. The experiment was laid out in factorial randomized block design with 12 treatments replicated thrice. The treatment combinations included three hybrids viz., H1- Sugar 75, H2- KSCH 333, H3- Misthi and four levels of micronutrient application viz., M1- RDN of Maize as per KAU POP (control), M2- RDN of Maize as per KAU POP + Spray of Boron as Solubor @ 0.15 per cent once at tasseling and silking, M3- RDN of Maize as per KAU POP + Spray of Zinc as ZnSO4 @ 1.0 per cent at 20 and 40 days after sowing and M4- RDN of Maize as per KAU POP + Spray of Boron as Solubor @ 0.15 per cent once at tasseling and silking + Spray of Zinc as ZnSO4 @ 1.0 per cent at 20 and 40 days after sowing. Perusal of the results on growth attributes revealed that sweet corn hybrids did not significantly influence plant height, number of leaves, leaf area, days to 50 per cent tasseling and silking, days to maturity and number of harvests. However, significant effects of hybrids were recorded in dry matter production. Highest dry matter accumulation was noticed in Sugar 75 (12027 kg ha-1) and was statistically on par with Misthi (9962 kg ha-1). Recommended dose of nutrients alone had resulted in highest plant height at 15 DAS and was on par with combined foliar application of zinc and boron. Leaf area was recorded maximum at 15 and 45 DAS in control plot and at 45 DAS, the treatment was on par with foliar application of zinc. Number of days taken for 50 per cent tasseling, silking and maturity was least in the control plot. Number of harvests did not differ significantly with micronutrient application. However, growth attributes did not show any significant variation between hybrids and their interaction with zinc and boron. Hybrids did not differ in any of the yield attributes recorded. However, total cob yield and green stover yield varied significantly with hybrids. Among the different hybrids tested, Sugar 75 was superior recording a cob yield of 11102 kg ha-1. Green stover yield was the highest in Sugar 75 (20667 kg ha-1) and was on par with Misthi (19111 kg ha-1). Among the yield attributes, the highest cob length was noticed in the control plot and was on par with foliar application of zinc and boron. Maximum cob girth was recorded in the control plot and was statistically on par with foliar application of zinc. Cob weight without husk was maximum when treated with recommended dose of fertilizers alone and was on par with foliar application of boron. Foliar nutrition with either zinc, boron or both had no influence on number of cobs per plant, number of kernel rows per cob, number of kernels per cob, hundred fresh kernel weight, cob weight with husk, total cob and stover yield. Visual symptoms of boron deficiency were observed in cobs irrespective of the treatments. The hybrids and their interaction with foliar application of micronutrients did not show significant influence on yield attributes. However, maximum cob yield (11640 kg ha-1) was recorded when recommended dose of nutrients alone were given and among interaction effects, the highest cob yield (13813 kg ha-1) was recorded when Sugar-75 was provided with recommended dose of nutrients alone and was on par with KSCH 333 and recommended dose of nutrients alone (13247 kg ha-1). Organic carbon and available boron content in the soil was not significantly influenced by hybrids, micronutrient application and their interaction. However, after harvest, there was an increase in the organic carbon content in the soil. Available boron content in the soil was in deficient range before and after the experiment. Chlorophyll content did not vary significantly with hybrids and micronutrient application. Highest chlorophyll content (2.44 mg g-1) was recorded when KSCH 333 was treated with recommended dose of fertilizers alone and was on par with all the interaction effects except when KSCH 333 was treated with foliar application of zinc and boron. Ascorbic acid content and moisture content was not significant among treatments. Among the hybrids, mean per cent damage by fall army worm was recorded the lowest in Misthi. Micronutrient application and their interaction with hybrids did not significantly influence the pest incidence. Highest net profit of ₹ 225710 ha-1 and BCR of 2.03 was realized with Sugar 75. Therefore, it can be concluded from the study that growing sweet corn hybrid Sugar 75 is beneficial for getting higher yield per unit area and maximum economic returns. Visual symptoms of boron deficiency were evident, reflected as unfilled kernel rows within the cobs of sweet corn. The study also reveals that boron is a critical nutrient that influences the yield and yield attributes in sweet corn. Foliar application of boron @ 0.15 per cent once at tasseling and silking did not meet the requirements of the crop when grown in boron deficient soil. Hence, foliar application of a nutrient alone cannot alleviate the nutrient deficiency in the crop when grown under limited soil nutrient supply.ThesisItem Open Access Combined application of granular preparations of pre-emergent herbicides and fertilizers in rice(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Bindu, N K; KAU; John, P SA field experiment was conducted at the Agricultural Research Station, Mannuthy under the Kerala Agricultural University during the first crop season of 1994 to find out the effect of pre-emergent herbicides and fertilizers in rice. The experiment was laid out in a randomized block design and consisted of fourteen treatments with three replications. Broadleaved weeds and sedges dominated the field. Among broadleaved weeds, Mono choria vaginalis and sphenocleazeylanica were predomint. Shoenoplectus lateriflorus and Cyperus difformis were the prominent sedges present in the field and Echinochloa colonum,saccolepis interrrupta and Isachne miliacea were the important grasses present. Butachlor, anilofos and oxyflourfen under different methods of application reduced the weed Population. Though oxyflourfen recorded high weed control efficiency, it was highly phytotoxic to the rice crop and resulted in poor crop stand. Butachlor and anilofos applied as homemade granular (GP) preparation or as spray alone, or in combination with fertilizer was safe to the crop. The available nutrient in the soil was not affected by the different methods of application of butachlor and anilofos, alone or when combined with fertilizer. Butachlor and anilofos as spray or as GP applied alone, or in combination with fertilizer recorded similar crop growth characteristics, yield and yield attributes. Nutrient up taken by weeds was lower in butachlor and anilofos treatment. Lower weed index values were recorded in butachlor and anilofos treatment. The highest return per rupee was obtained from anilofos treatments. The highest return per rupees was obtained from anilofos treatments. In general, combined application of anilofos or butachlor GP with fertilizer gave efficient control of weed, produced higher grain yields and high return per rupee invested. It also reduced cost, energy and time of weed control operation.ThesisItem Open Access Standardisation of fertilizer schedule for export oriented production of bhindi(Department of Agronomy, College of Agriculture, Vellayani, 1993) Sajitharani, T; KAU; Pushpakumari, RAn experiment was conducted at the instructional farm, College of Agriculture, Vellayani to find out the effect of different levels of fertilizers and their split application on the growth, yield, quality and nutrient uptake of bhindi. Abelmoschus esculentus (L) Moench. The treatments consisted of four levels of nutrients Viz. (330: 110: 220 kg N2 P2O5 & K2O), the present T & V recommendation, 2/3 of the T & V recommendation, 1/3 of the T & V recommendation and 50: 8: 30 kg NP2O5 & K2O per hectare the present package of practices recommendation and 3 methods of application viz. nutrients in 2 splits, 4 splits and 6 splits. The results revealed that nutrient levels significantly influenced most of the growth and yield contributing characters and yield of bhindi. Biometric characters like plant height, LAI, CGR, DMP and yield contributing characters like days to 50 percent flowering, number of flowers formed, number of fruits formed total yield of fruits and quality parameters like protein content and ascorbic acid content increased with increasing levels of nutrients, recording their maximum value at F1 level, (T and V recommendation). Uptake of nutrients by plants, fruits and total was also maximum for the same treatment. However yield attributes viz. setting percentage, length and girth of fruits etc. remain unchanged with increasing levels of nutrients. Application of fertilizer nutrients in different splits viz. 2,4 or 6 cause significant variation in some of the growth and yield characters. An increase in the plant height at 60 DAS, DMP, days taken for 50 percent flowering and uptake of nutrients was noticed when nutrients were supplied in two equal splits, viz half as basal and half 30 DAS (S1). On the other hand the ascorbic acid content in fruits was maximum when nutrients were applied in six splits. Application of nutrients in 6 splits caused a significant reduction in the crude fibre content also. From the economic point of view, the maximum net profit of Rs.13682.54 was obtained by F3 level (2/3 of T and V recommendation) and Rs.14710.8 by S1 (2 equal splits half as basal and half 30 DAS).ThesisItem Open Access Biology and management of goose weed (Sphenoclea zeylanica Gaertner) in wetland rice(Department of Agronomy, College of Agriculture, Vellayani, 2020) Mallu Sai Sarath Kumar, Reddy.; KAU; Ameena, MAn investigation entitled ‘Biology and management of goose weed (Sphenoclea zeylanica Gaertner) in wetland rice’ was conducted at College of Agriculture, Vellayani during 2018-2020. The major objectives were to study the biology of the weed, its allelopathic effect on crop and also to develop an effective and economic management strategy using herbicides in wet seeded rice. The field experiment was undertaken at IFSRS, Karamana during kharif 2019. Weed biology was studied by observing randomly selected sample plants in weedy check plots starting from the emergence of the weed. The field experiment was laid out in randomized block design with eight treatments and three replications. The weed control treatments included T1: bensulfuron methyl + pretilachlor @ 60+600 g ha-1 at 5 days after sowing(DAS), T2: pyrazosulfuron ethyl @ 25g ha-1 at 5 DAS, T3: bispyribac sodium @ 25 g ha-1 at 15-20 DAS, T4 :penoxsulam + cyhalofop butyl 6% OD at 150 g ha-1 at 20 DAS, T5: metsulfuron methyl + chlorimuron ethyl @ 4g ha-1 at 20 DAS, T6: ethoxysulfuron @ 15 g ha-1 at 20 DAS, T7 : hand weeding at 20 and 40 DAS, T8 : weedy check ( unweeded control) and the treatments T1 to T6 were followed by hand weeding at 35-40 DAS. The lab experiment on allelopathic effect of goose weed on germination and growth of rice seedlings was evaluated with treatments T1: Fresh leaves aqueous extract 10%, T2: Dry leaves aqueous extract 10%, T3: Fresh stem aqueous extract 10%, T4: Dry stem aqueous extract 10%, T5: Fresh inflorescence aqueous extract 10%, T6: Dry inflorescence aqueous extract 10%, T7: Fresh whole plant aqueous extract before flowering 10%, T8: Fresh whole plant aqueous extract after flowering 10%, T9: Distilled water (control). The data on weed biology identified goose weed as an annual. The weed seeds took 3-7 days for germination, 15 days for flowering and 36 days for first spike maturity with an average duration of 69 days in wet seeded rice fields. The weed was observed to propagate by seeds with enormous seed production potential. The average dry matter produced per plant and total dry matter production were to the tune of 26.24 g per plant and 3.75 t ha-1 respectively in the weedy check. The weed was analysed to contain 1.306, 0.087 and 1.695 per cent N, P and K respectively. In the field experiment, Sphenoclea zeylanica was the dominant weed flora during all the growth stages of the crop. Initially, a lower weed density was recorded in T1, but taken over by T4 at 30, 45 and 60 DAS. The weed dry weight was the lowest in T1 at 15 and 30 DAS (0.08 and 6.41 g m-2), whereas at 45 and 60 DAS, T4 recorded the lowest values (1.35 and 4.61 g m-2). T1 registered lesser relative weed density of S. zeylanica up to one month and later by T4. Unweeded plot showed dominance of the weed over other flora with a relative density of 70.33 per cent. Though weed control efficiency was higher in T1 upto 30 DAS (99.28 and 96.22 per cent), T4 recorded higher values during critical stages of crop growth at 45 and 60 DAS (99.54 and 98.85 per cent). T4, T1 and T5 recorded minimum NPK removal and to be precise only one tenth of N removal registered in weedy check in comparison to others due to lower weed dry matter accumulation Among the weed management practices tested, T1 recorded higher plant height at 30, 60 DAS and at harvest. Both T1 and T4 recorded higher yield and yield attributes like number of panicles m-2(320 and 308.3), number of grains panicle-1 (173 and 177), grain yield (5461 and 5355 kg ha-1) and straw yield (7710 and 7646 kg ha-1). Bensulfuron methyl + pretilachlor @ 60+600 g ha-1 at 5 DAS followed by hand weeding at 35-40 DAS turned out to be the most economic weed management practice with a higher B: C ratio of 1.83. This was followed by penoxsulam + cyhalofop butyl 6% OD at 150 g ha-1 at 20 DAS followed by hand weeding at 35-40 DAS with a B: C ratio of 1.77. Higher nutrient uptake by the crop was noticed in bensulfuron methyl + pretilachlor (T1), T4 and T5 due to higher dry matter production. The extent of yield reduction due to presence of weeds in wet seeded rice was estimated to be 57 per cent. The study on allelopathic influence of goose weed revealed strong inhibitory influence for its dry leaves and dry inflorescence on germination percentage (92.67 and 80%) and dry weight (96.98 and 96.12%) of rice seedlings. Shoot length, root length, fresh weight, dry weight and vigour index were also recorded the lowest in T2 and T6. From the results of the study, it could be concluded that Sphenoclea zeylanica could become a serious weed in wetland rice fields being a prolific seed producer with high dry matter production. Application of bensulfuron methyl + pretilachlor @ 60+600 g ha-1at 5 DAS followed by hand weeding at 35-40 DAS was found to be the most effective and economic management strategy. The inference of allelopathic studies indicated that dry leaves and inflorescence of goose weed have strong inhibitory influence affecting germination and growth of rice.
